This PDF file contains the front matter associated with SPIE Proceedings Volume 8000, including the Title Page, Copyright information, Table of Contents, Introduction, and Conference Committee listing.

Electron Multiplying CCDs (EMCCDs) are used much less often than they might be because of the challenges they offer camera designers more comfortable with the design of slow-scan detector systems. However they offer an entirely new range of opportunities in astrophysical instrumentation. This paper will show some of the exciting new results obtained with these remarkable devices and talk about their potential in other areas of astrophysical application. We will then describe how they may be operated to give the very best performance at the lowest possible light levels. We will show that clock induced charge may be reduced to negligible levels and that, with care, devices may be clocked at significantly higher speeds than usually achieved. As an example of the advantages offered by these detectors we will show how a multi-detector EMCCD curvature wavefront sensor will revolutionise the sensitivity of adaptive optics instruments and been able to deliver the highest resolution images ever taken in the visible or the near infrared.

EMCCDs are capable of extreme low light imaging thanks to sub-electron read-out noise, enabling single-photon counting. The characterization of e2v's CCD60 (128 x 128), CCD97 (512 x 512) and CCD201-20 (1024 x 1024) using a controller optimized for the driving of EMCCDs at a high (≥10 MHz) pixel rate per output with < 0.002 e^- total background signal. Using the CCD Controller for Counting Photons (CCCP), the horizontal and vertical CIC, dark current and EM gain stability are characterized.

The European Space Agency has funded e2v’s development of an image sensor for the visible instrument in the Euclid space telescope. Euclid has been selected for a medium class mission launch opportunity in 2020. The project aims to map the dark universe with two complementary methods; a galaxy red-shift survey and weak gravitational lensing using near infrared and visible instruments. The baseline for the visible instrument was to be the CCD203-82, which has been successfully flown on NASA’s Solar Dynamics Observatory. However, to optimise the device for Euclid, e2v have designed and manufactured the CCD273-84. This device has a higher-responsivity lower-noise amplifier, enhanced red response, parallel charge injection structures and narrower registers which improve low signal charge transfer efficiency. Development models for Euclid have been manufactured with a thinner gate dielectric than standard for improved tolerance to ionising radiation. This paper describes the imager sensor in detail and focuses on the novel aspects of the device, package and interface.

We describe work at Lawrence Berkeley National Laboratory (LBNL) to develop enhanced performance, fully depleted, back-illuminated charge-coupled devices for astronomy and astrophysics. The CCDs are fabricated on high-resistivity substrates and are typically 200–300 μm thick for improved near-infrared response. The primary research and development areas include methods to reduce read noise, increase quantum efficiency and readout speed, and the development of fabrication methods for the efficient production of CCDs for large focal planes. In terms of noise reduction, we will describe technology developments with our industrial partner Teledyne DALSA Semiconductor to develop a buried-contact technology for reduced floating-diffusion capacitance, as well as efforts to develop ”skipper” CCDs with sub-electron noise utilizing non-destructive readout amplifiers allowing for multiple sampling of the charge packets. Improvements in quantum efficiency in the near-infrared utilizing ultra-high resistivity substrates that allow full depletion of 500 μm and thicker substrates will be described, as well as studies to improve the blue and UV sensitivity by investigating the limits on the thickness of the back-side ohmic contact layer used in the LBNL technology. Improvements in readout speed by increasing the number of readout ports will be described, including work on high frame-rate CCDs for x-ray synchrotrons with as many as 192 amplifiers per CCD. Finally, we will describe improvements in fabrication methods, developed in the course of producing over 100 science-grade 2k × 4k CCDs for the Dark Energy Survey Camera.

We describe vacuum ultraviolet sensitivity measurements of a new high performance silicon-based CMOS sensor from Teledyne Imaging Sensors. These sensors do not require the high voltages of MCP detectors, making them a lower mass and power alternative to the more mature MCP technology. These devices demonstrate up to 40 percent quantum efficiency at vacuum ultraviolet wavelengths, either meeting or greatly exceeding 10 percent quantum efficiency across the entire 100-200 nm wavelength region. As with similar visible sensitive devices, backside illumination results in a higher quantum efficiency than frontside illumination. Measurements of the vacuum ultraviolet sensitivity of the Teledyne silicon PIN detectors were made by directing a known intensity of ultraviolet light at discrete wavelengths onto the test detectors and reading out the resulting photocurrent. The sensitivity of the detector at a given wavelength was then calculated from the intensity and wavelength of the incoming light and the relative photodiode to NIST-traceable calibration diode active areas. A custom electromechanical interface was developed to make these measurements within the SwRI Vacuum Radiometric Calibration Chamber. While still in the single pixel stage, full 1K × 1K focal plane arrays are possible using existing CMOS readout electronics and hold great promise for inclusion in future spaceflight instrument concepts.

We describe recent progress in the development of anti-reflection coatings for use at UV wavelengths on CCDs and other Si-based detectors. We have previously demonstrated a set of coatings which are able to achieve greater than 50% QE in 4 bands from 130nm to greater than 300nm. We now present new refinements of these AR-coatings which will improve performance in a narrower bandpass by 50% over previous work. Successful test films have been made to optimize transmission at 190nm, reaching 80% potential transmission.

Microwave Kinetic Inductance Detectors, or MKIDs, have proven to be a powerful cryogenic detector technology due to their sensitivity and the ease with which they can be multiplexed into large arrays. An MKID is an energy sensor based on a photon-variable superconducting inductance in a lithographed microresonator. It is capable of functioning as both a photon detector across the electromagnetic spectrum and a particle detector. We have recently demonstrated the world's first photon-counting, energy-resolving, ultraviolet, optical, and near infrared MKID focal plane array in the ARCONS camera at the Palomar 200" telescope. Optical Lumped Element (OLE) MKID arrays have significant advantages over semiconductor detectors such as charge coupled devices (CCDs). They can count individual photons with essentially no false counts and determine the energy (to a few percent) and arrival time (to ≈1μs) of every photon, with good quantum efficiency. Initial devices were degraded by substrate events from photons passing through the Titanium Nitride (TiN) material of the resonator and being absorbed in the substrate. Recent work has eliminated this issue, with a solution found to be increasing the thickness of the TiN resonator from 20 to 60 nm.

The success of the next generation of instruments for 8 to 40-m class telescopes will depend upon improving the image quality (correcting the distortion caused by atmospheric turbulence) by exploiting sophisticated Adaptive Optics (AO) systems. One of the critical components of the AO systems for the E-ELT has been identified as the Laser/Natural Guide Star (LGS/NGS) WaveFront Sensing (WFS) detector. The combination of large format, 1760x1680 pixels to finely sample (84x84 sub-apertures) the wavefront and the spot elongation of laser guide stars, fast frame rate of 700 (up to 1000) frames per second, low read noise (< 3e-), and high QE (> 90%) makes the development of such a device extremely challenging. Design studies by industry concluded that a thinned and backside-illuminated CMOS Imager as the most promising technology. This paper describes the multi-phased development plan that will ensure devices are available on-time for E-ELT first-light AO systems; the different CMOS pixel architectures studied; measured results of technology demonstrators that have validated the CMOS Imager approach; the design explaining the approach of massive parallelism (70,000 ADCs) needed to achieve low noise at high pixel rates of ~3 Gpixel/s ; the 88 channel LVDS data interface; the restriction that stitching (required due to the 5x6cm size) posed on the design and the solutions found to overcome these limitations. Two generations of the CMOS Imager will be built: a pioneering quarter sized device of 880x840 pixels capable of meeting first light needs of the E-ELT called NGSD (Natural Guide Star Detector); followed by the full size device, the LGSD (Laser Guide Star Detector). Funding sources: OPTICON FP6 and FP7 from European Commission and ESO.

In this paper, we present an overview of high-performance CMOS image sensor products developed at BAE SYSTEMS Imaging Solutions designed to satisfy the increasingly challenging technical requirements for image sensors used in advanced scientific, industrial, and low light imaging applications. We discuss the design and present the test results of a family of image sensors tailored for high imaging performance and capable of delivering sub-electron readout noise, high dynamic range, low power, high frame rates, and high sensitivity. We briefly review the performance of the CIS2051, a 5.5-Mpixel image sensor, which represents our first commercial CMOS image sensor product that demonstrates the potential of our technology, then we present the performance characteristics of the CIS1021, a full HD format CMOS image sensor capable of delivering sub-electron read noise performance at 50 fps frame rate at full HD resolution. We also review the performance of the CIS1042, a 4-Mpixel image sensor which offers better than 70% QE @ 600nm combined with better than 91dB intra scene dynamic range and about 1 e- read noise at 100 fps frame rate at full resolution.

Future space-based X-ray telescope missions are likely to have significantly increased demands on detector read out rates due to increased collection area, and there will be a desire to minimize radiation damage in the interests of maintaining spectral resolution. While CCDs have met the requirements of past missions, active pixel sensors are likely to be a standard choice for some future missions due to their inherent radiation hardness and fast, flexible read-out architecture. One form of active pixel sensor is the hybrid CMOS sensor. In a joint program of Penn State University and Teledyne Imaging Sensors, hybrid CMOS sensors have been developed for use as X-ray detectors. Results of this development effort and tests of fabricated detectors will be presented, along with potential applications for future missions.

We present the results of x-ray measurements on a hybrid CMOS detector that uses a H2RG ROIC and a unique bonding structure. The silicon absorber array has a 36μm pixel size, and the readout array has a pitch of 18μm; but only one readout circuit line is bonded to each 36x36μm absorber pixel. This unique bonding structure gives the readout an effective pitch of 36μm. We find the increased pitch between readout bonds significantly reduces the interpixel capacitance of the CMOS detector reported by Bongiorno et al. 2010¹ and Kenter et al. 2005.²

We present preliminary results from our ongoing program to develop CMOS detectors as single photon counting, soft X-ray imaging spectrometers. The Smithsonian Astrophysical Observatory in collaboration with SRI International/ Sarnoff has been developing monolithic CMOS detectors optimized for x-ray astronomy. Our latest detector consists of an array of 1k × 1k 16 μm pixels manufactured on 15μm epitaxial Si. These detectors are designed to be packaged and thinned for back illumination. The devices have on-chip CDS and are optimized to have high (~ 40 frame/sec) read-out rates. Such monolithic CMOS imaging sensors would be ideal candidate detectors for the focal planes of space-borne soft x-ray astronomy missions. The high through-put, low noise and excellent low energy response, provide high dynamic range and good time resolution; bright and time varying x-ray features could be temporally and spectrally resolved without saturation or photon pile-up.

The J-PAS (Javalambre Physics-of-the-Accelerating-Universe Astrophysical Survey) project will perform a five-year survey of the northern sky from a new 2.5m telescope in Teruel, Spain. We describe the design concept of a complete cryogenic camera with a mosaic focal plane and 1.2 gigapixel science array which is to be commercially supplied. The focal plane is contained within a novel liquid-nitrogen-cooled vacuum cryostat, with proximity drive electronics designed to achieve a 4 e- readout noise from the 224-channel CCD system.

We will report on the on-sky, on-CCD, tip-tilt image compensation performance of GPC1, the 1.4 gigapixel mosaic focal plane CCD camera for wide field surveys with a 7 square degree field of view. The camera uses 60 Orthogonal Transfer Arrays (OTAs) with a novel 4 phase pixel architecture and the STARGRASP controller for closed loop multi-guide star centroiding and image correction. The Pan-STARRS project is also constructing GPC2, the second 1.4 gigapixel camera using 64 OTAs. GPC2 will include design enhancements over GPC1 including a new generation of OTAs, titanium mosaic focal plane with adjustable three point kinematic mounts, cyro flex wiring and the recent software distributed over 32 controllers. We will discuss the design, cost, schedule, tools developed, shortcomings and future plans for the two largest digital cameras in the world.

The science focal plane of the Large Synoptic Survey Telescope is made up of 21 modules designated "raft towers". Each raft tower module (RTM) is an autonomous, fully-testable and serviceable 144 Mpixel imager consisting of nine highly-segmented CCDs with complete readout electronics chain. To minimize noise and obscuration the RTM is housed in a compact enclosure fully contained within the camera cryostat. The RTM is required to meet strict performance goals for image plane flatness, readout speed, noise, and power dissipation. Key components include the 4K × 4K fully-depleted CCDs with 16 outputs each, ceramic CCD support structure, and ASIC electronics for video processing and clock/bias generation. In addition to CCD signal handling, the RTM electronics also includes monitoring for temperature, voltage, and current, makeup heater control, ASIC configuration and readback, powerdown modes, and specialized diagnostic outputs. Digitized data are transmitted out of the camera cryostat over a single 3Gb/s serial link.

Teledyne’s silicon hybrid CMOS focal plane array technology has matured into a viable, high performance and high- TRL alternative to scientific CCD sensors for space-based applications in the UV-visible-NIR wavelengths. This paper presents the latest results from Teledyne’s low noise silicon hybrid CMOS visible focal place array produced in 4K×4K format with 10 μm pixel pitch. The H4RG-10 readout circuit retains all of the CMOS functionality (windowing, guide mode, reference pixels) and heritage of its highly successful predecessor (H2RG) developed for JWST, with additional features for improved performance. Combined with a silicon PIN detector layer, this technology is termed HyViSI™ (Hybrid Visible Silicon Imager). H4RG-10 HyViSI™ arrays achieve high pixel interconnectivity (<99.99%), low readout noise (<10 e- rms single CDS), low dark current (<0.5 e-/pixel/s at 193K), high quantum efficiency (<90% broadband), and large dynamic range (<13 bits). Pixel crosstalk and interpixel capacitance (IPC) have been predicted using detailed models of the hybrid structure and these predictions have been confirmed by measurements with Fe-55 Xray events and the single pixel reset technique. For a 100-micron thick detector, IPC of less than 3% and total pixel crosstalk of less than 7% have been achieved for the HyViSI™ H4RG-10. The H4RG-10 array is mounted on a lightweight silicon carbide (SiC) package and has been qualified to Technology Readiness Level 6 (TRL-6). As part of space qualification, the HyViSI™ H4RG-10 array passed radiation testing for low earth orbit (LEO) environment.

To improve the signal to noise level, devices for optical and x-ray astronomy use techniques to suppress background events. Well known examples are e.g. shutters or frame-store Charge Coupled Devices (CCDs). Based on the DEpleted P-channel Field Effect Transistor (DEPFET) principle a so-called Gatebale DEPFET detector can be built. Those devices combine the DEPFET principle with a fast built-in electronic shutter usable for optical and x-ray applications. The DEPFET itself is the basic cell of an active pixel sensor build on a fully depleted bulk. It combines internal amplification, readout on demand, analog storage of the signal charge and a low readout noise with full sensitivity over the whole bulk thickness. A Gatebale DEPFET has all these benefits and obviates the need for an external shutter. Two concepts of Gatebale DEPFET layouts providing a built-in shutter will be introduced. Furthermore proof of principle measurements for both concepts are presented. Using recently produced prototypes a shielding of the collection anode up to 1 • 10⁻⁴ was achieved. Predicted by simulations, an optimized geometry should result in values of 1 • 10⁻⁵ and better. With the switching electronic currently in use a timing evaluation of the shutter opening and closing resulted in rise and fall times of 100ns.

We developed and tested X-ray PNCCD focal plane detectors for the eROSITA (extended ROentgen Survey with an Imaging Telescope Array) space telescope. General scientific goal of the eROSITA project is the exploration of the X-ray universe in the energy band from about 0.2 keV up to 10 keV with excellent energy, time, and spatial resolution in combination with large effective telescope areas. The observational program divides into an all-sky survey and pointed observations. The mission duration is scheduled for 7.5 years. The German instrument will be launched in near future to the Lagrange point L2 on the Russian satellite SRG. The detection of single X-ray photons with precise information about their energy, angle of incidence and time is accomplished for eROSITA by an array of seven identical and independent PNCCD cameras. Each camera is assigned to a dedicated mirror system of Wolter-I type. The key component of the camera is a 5 cm • 3 cm large, back-illuminated, 450 μm thick and fully depleted frame store PNCCD chip. This chip is a further development of the sensor type that is in operation as focal plane detector on the XMMNewton satellite since launch in 1999 to date. Development and production of the CCDs for the eROSITA project were performed by the MPI Halbleiterlabor, as already in the past for the XMM-Newton project. According to the status of the project, a complete design of the seven flight cameras including the camera electronics and the filter wheel has been developed. Various functional and performance tests have been accomplished for a detailed characterization of the eROSITA camera system. We focus here especially on the focal plane detector design and the performance of the detectors, which are essential for the success of the X-ray astronomy space project.

The Mercury Imaging X-ray Spectrometer (MIXS) is an instrument on board of the 5th ESA cornerstone mission BepiColombo. This Spectrometer comprises two instruments for imaging x-ray spectroscopy of the Mercury surface. The detector plane arrays (DPA) for the energy and spatial resolved detection of x-rays are based on DEPFET (Depleted P-channel FET) macropixel detectors with 64×64 pixel each and 300×300 μm² pixel size. The MIXS target energy band is from 0.5 to 7 keV with an energy resolution better than 200 eV at 1 keV at mission end. This allows to access the Fe-L line at about 0.7 keV, which was not accessible to previous instruments, and to separate the x-ray lines of the elements of interest. Before a detector chip is integrated into a detector module, it is electrically pre-characterized in order to select only the best chips for the complex and time-consuming integration. The high degree of complexity of the integration process comes from the need to thermally decouple the detector chip from its readout and steering ASICs by a sophisticated mechanical structure, due to the limited amount of cooling power available for the instrument. After the spectroscopic characterization of the detector modules, the flight and flight spare detectors were calibrated at the PTB (Physikalisch-Technische Bundesanstalt) beamlines at the BESSY-II synchrotron. We report on the pre-characterization, integration, qualification and calibration of MIXS flight and flight spare detectors, which is now successfully completed.

The Chandrayaan-2 Large Area Soft X-ray spectrometer (CLASS) is due to be launched by the Indian Space Research Organisation (ISRO) in 2014. It will map the elemental composition of the lunar surface, building on the Chandrayaan-1 X-ray spectrometer (C1XS) heritage. CLASS will use an array of e2v technologies CCD236 swept charge devices (SCD) providing an active detector area of approximately 64 cm², almost three times the active area of C1XS which used the first generation of SCD, the CCD54. The CCD236 is designed as a soft X-ray detector, 0.8 keV to 10 keV, and benefits from improvements in design to allow for increased detector area, a reduction in split X-ray events and improvements to radiation hardness. This paper describes the investigation into the performance requirements of the CCD236, focussing on an optimisation of the energy resolution of a device irradiated to the estimated worse case end of life proton fluence.

The development of new focusing optics based on wide band Laue lenses operating from ~60 keV up to several hundred keV is particularly challenging. This type of hard X-ray or gamma ray optics requires a high performance focal plane detector in order to exploit to the best their intrinsic capabilities. We describe a three dimensional (3D) position sensitive detector prototype suitable as the basic module for a high efficiency Laue lens focal plane detector. This detector configuration is currently under study for use in a balloon payload dedicated to performing a high significance measurement of the polarization status of the Crab between 100 and 500 keV. The prototype is made by packing 8 linear modules, each composed of one basic sensitive unit bonded onto a thin supporting ceramic layer. Each unit is a drift strip detector based on a CZT crystal, irradiated transversally to the electric field direction. The anode is segmented into 8 detection cells, each comprising one collecting strip and 8 surrounding drift strips. The drift strips are biased by a voltage divider. The cathode is divided into 4 horizontal strips for the reconstruction of the Z interaction position. The detector readout electronics is based on RENA-3 ASIC and the data handling system uses a custom electronics based on FPGA to provide the ASIC setting, the event handling logic, and the data acquisition. This paper mainly describes the components and the status of the undergoing activities for the construction of the proposed 3D CZT prototype and shows the results of the electronics tests.

The performance of the current high speed near infrared HgCdTe sensors operating in fringe trackers, wavefront sensors and tip-tilt sensors is severely limited by the noise of the silicon readout interface circuit (ROIC), even if state-of-the- art CMOS designs are used. A major improvement can only be achieved by the amplification of the photoelectron signal directly at the point of absorption by means of avalanche gain inside the infrared pixel. Unlike silicon, HgCdTe offers noiseless avalanche gain. This has been verified with the LPE grown 320x256 pixel λ_c=2.5 μm HgCdTe eAPD arrays from SELEX both on a prototype ROIC called SWALLOW and on a newly developed ROIC, specifically designed for AO applications, called SAPHIRA. The novel features of the new SAPHIRA ROIC, which has 32 parallel video channels operating at 5 MHz, will be described, together with the new high speed NGC data acquisition system. Performance results will be discussed for both ROICs. The LPE material on the SWALLOW prototype was excellent and allowed operation at an APD gain as high as 33. Unfortunately, the LPE material of the first devices on the SAPHIRA ROIC suffers from problems which are now understood. However, due to the excellent performance of the SAPHIRA ROIC even with the limitations of present HgCdTe material, it is possible with simple double correlated sampling to detect test patterns with signal levels of 1 electron. An outlook will be given on further developments of heterojunctions grown by MOVPE, which eventually may replace eAPD arrays grown by LPE.

The European Space Agency (ESA) has funded SELEX Galileo, Southampton, UK to develop large format near infrared (NIR) detectors for its future space and ground based programmes. The UKATC has worked in collaboration with SELEX Galileo to test and characterise the new detectors produced during phase-1 of the development. In order to demonstrate the detector material performance, the HgCdTe (MCT) detector diodes (grown on GaAs substrate through MOVPE process in small 320×256, 24μm pixel format) are hybridised to the existing SELEX Galileo SWALLOW CMOS readout chip. The substrate removed and MCT thinned detector arrays were then tested and evaluated at the UKATC following screening tests at SELEX. This paper briefly describes the test setup, the operational aspects of the readout multiplexer and presents the performance parameters of the detector arrays including: conversion gain, detector dark current, read noise, linearity, quantum efficiency and persistence for various detector temperatures between 80K and 140K.

In preparation for the large number of infrared pixels required in the era of Extremely Large Telescopes, Teledyne, in partnership with the University of Hawaii and GL Scientific, has been funded to develop the next generation of largeformat infrared focal plane array for ground-based astronomy; the 4096 × 4096 pixel (15 micron pitch) H4RG-15. Teledyne has successfully designed, produced, and tested the first generation H4RG-15 prototype arrays. This paper reports on the functionality and performance test results of the H4RG-15 prototypes and provides status of the 2012 pilot production effort.

The primary goal of the HAWAII 4RG-15 (H4RG-15) development is to provide a 16 megapixel 4096x4096 format at significantly reduced price per pixel while maintaining the superb low background performance of the HAWAII 2RG (H2RG). The H4RG-15 design incorporates several new features, notably clocked reference output and interleaved reference pixel readout, that promise to significantly improve noise performance while the reduction in pixel pitch from 18 to 15 microns should improve transimpedance gain although at the expense of some degradation in full well and crosstalk. During the Phase-1 development, Teledyne has produced and screen tested six hybrid arrays. In preparation for Phase-2, the most promising of these are being extensively characterized in the University of Hawaii’s (UH) ULBCam test facility originally developed for the JWST H2RG program. The end-to-end performance of the most promising array has been directly established through astronomical imaging observations at the UH 88-inch telescope on Mauna Kea. We report the performance of these Phase-1 H4RG-15s within the context of established H2RG performance for key parameters (primarily CDS read noise), also highlighting the improvements from the new readout modes.

A camera operating a Teledyne H2RG in H and Ks bands is under construction at Caltech to serve as a near-infrared tip-tilt sensor for the Keck-1 Laser Guide Star Adaptive Optics system. After imaging the full field for acquisition, small readout windows are placed around one or more natural guide stars anywhere in the AO corrected field of view. Windowed data may be streamed to RAM in the host for a limited time then written to disk as a single file, analogous to a “film strip”, or be transmitted indefinitely via a second fiber optic output to a dedicated computer providing real time control of the AO system. The various windows can be visited at differing cadences, depending on signal levels. We describe a readout algorithm that maximizes exposure duty cycle, minimizes latency, and achieves very low noise by resetting infrequently then synthesizing exposures from Sample Up The Ramp data. To illustrate which noise sources dominate under various conditions, noise measurements are presented as a function of synthesized frame rate and window sizes for a range of detector temperatures. The consequences of spatial variation in noise properties, and dependence on frame rate and temperature are discussed, together with probable causes of statistical outliers.

Teledyne’s H2RG focal plane arrays have been widely used in scientific infrared and visible instruments for ground-based and space-based telescopes. The majority of applications use the H2RG with 2.5 micron cutoff HgCdTe detector pixel at an operating temperature of ~77 K (LN₂). The exceptionally low dark current of the 2.5 micron H2RG allows for operation at higher temperatures which facilitates simplified instrument designs and therefore lower instrument cost. Performance data of 2.5 micron H2RG arrays at 77K, 100 K, and 120 K are presented and are discussed as a function of detector bias and pixel readout rate. This paper also presents performance data of 1.75 micron and 5.3 micron H2RG focal plane arrays and discusses some of the inherent performance differences compared to 2.5 micron cutoff arrays. A complete infrared camera system that uses the H2RG focal plane array and SIDECAR ASIC focal plane electronics is introduced.

ESO has recently funded the development of the AQUARIUS detector at Raytheon Vision Systems, a new mega-pixel Si:As Impurity Band Conduction array for use in ground based astronomical applications at wavelengths between 3 – 28 μm. The array has been designed to have low noise, low dark current, switchable gain and be read out at very high frame rates. It has 64 individual outputs capable of pixel read rates of 3MHz, implying continuous data-rates in excess of 300 Mbytes/second. It is scheduled for deployment into the VISIR instrument at the VLT in 2012, for next generation VLTI instruments and base-lined for METIS, the mid-IR candidate instrument for the E-ELT. A new mid-IR test facility has been developed for AQUARIUS detector development which includes a low thermal background cryostat, high speed cryogenic pre-amplification and high speed data acquisition and detector operation at 5K. We report on all the major performance aspects of this new detector including conversion gain, read noise, dark generation rate, linearity, well capacity, pixel operability, low frequency noise, persistence and electrical cross-talk. We describe the many possible readout modes of this detector and their application. We also report on external issues with the operation of these detectors at such low temperatures. Finally we report on the electronic developments required to operate such a detector at the required high data rates and in a typical mid-IR instrument.

The James Webb Space Telescope Fine Guidance Sensor makes use of three 2048x2048 five micron cutoff HAWAII-2RG HgCdTe detectors from Teledyne Imaging Systems. The FGS consists of two Guider channels and a Near-InfraRed Imager and Slitless Spectrograph (NIRISS) channel. We report here on the characterization of the flight detectors at the sub-system level and after integration to the flight instrument. The FGS-Guider has a number of unique readout modes which are required to support observatory operations. Of critical importance is the identification and classification of pixels which, if left unmasked or unprocessed, would compromise the guider performance. We report on these classification methods and on the detailed behaviour of key bad pixel types which can impact guider performance.

The ESA/NASA Solar Orbiter mission, to be launched in 2017, will explore the Sun at a much closer distance than any previous solar observatory. On board the spacecraft, a high-resolution magnetograph (PHI) will provide two-dimensional measurements of the photospheric vector magnetic field and line-of-sight velocity. The environmental conditions encountered during the mission, together with the stringent performance requirements of the instrument, define the set of specifications for the camera system. A custom designed CMOS sensor (with 2048×2050 pixels) has been developed to fulfill the aimed radiation hardness and performance. This sensor must demonstrate a cadence above 10 fps with a full-well capacity higher than 10⁵ electrons in a 10-μm pixel pitch. We report the characterization and qualification tests. The radiation test campaign has been completed up to a TID of 150 krad(Si), proton fluence up to 4 × 10¹¹ at 10 MeV and 2 × 10¹¹ at 20 MeV, and with heavy ions to check for latch-up and SEFI failures. In parallel, a radiation tolerant camera electronic readout system has been built to control the sensor and readout images, digitize the data, and communicate with the data handling system of the PHI instrument. In addition, we present the main issues related to the camera design and future perspectives.

As electrons are transferred through a radiation damaged Charge Coupled Device (CCD), they may encounter traps in the silicon in which they will be captured and subsequently released. This capture and release of electrons can lead to a 'smearing' of the image. The dynamics of the trapping process can be described through the use of Shockley-Read-Hall theory, in which exponential time constants are used to determine the probability of capture and release. If subjected to a hostile radiation environment, such as in space where the dominant charged particle is the proton, these incident protons can cause displacement damage within the CCD and lead to the formation of stable trap sites. As the trap density increases, the trapping and release of signal electrons can have a major impact on the Charge Transfer Efficiency (CTE) to the detriment of device performance. As the science goals for missions become ever more demanding, such as those for the ESA Euclid and Gaia missions, the problem of radiation damage must be overcome. In order to gain a deeper understanding of the trapping process and the impact on device performance, a Monte Carlo simulation has been developed to model the transfer of charge in a radiation damaged CCD. This study investigates the various difficulties encountered when developing such a model: the incorporation of appropriate clocking mechanisms, the use of suitable trap parameters and their degeneracy, and the development of methods to model the charge storage geometry within a pixel through the use of three-dimensional Silvaco simulations.

Euclid is a medium class mission selected for launch in 2019, with a primary goal to study the dark universe using the weak lensing and baryonic acoustic oscillations techniques. Weak lensing depends on accurate shape measurements, therefore it is beneficial that the effects of radiation-induced charge transfer inefficiency (CTI) in the Euclid CCD over the six year mission are understood and minimised. This paper describes the initial evaluation of the tolerance to radiation induced charge transfer inefficiency (CTI) of the CCD273 produced by e2v technologies plc, making comparisons with the previous CCD selected for Euclid the CCD203. The CCD273 benefits from the inclusion of a charge injection structure for trap suppression and a reduction in the register channel width. The improvement in tolerance to radiation induced serial CTI achieved by reducing the channel width from 50 μm to 20 μm was measured experimentally to be a factor of 1.7, which compares well to a factor of 1.9 found using a charge volume model

The charge transfer efficiency of a CCD is based on the average level of signal lost per pixel over a number of transfers. This value can be used to directly compare the relative performances of different structures, increases in radiation damage or to quantify improvements in operating parameters. This number does not however give sufficient detail to mitigate for the actual signal loss/deference in either of the transfer directions that may be critical to measuring shapes to high accuracy, such as those required in astronomy applications (e.g. for Gaia’s astrometry or the galaxy distortion measurements for Euclid) based in the radiation environment of space. Pocket-pumping is an established technique for finding the location and activation levels of traps; however, a number of parameters in the process can also be explored to identify the trap species and location to sub-pixel accuracy. This information can be used in two ways to increase the sensitivity of a camera. Firstly, the clocking process can be optimised for the time constant of the majority of traps in each of the transfer directions, reducing deferred charge during read out. Secondly, a correction algorithm can be developed and employed during the post-processing of individual frames to move most of any deferred signal back into the charge packet it originated from. Here we present the trap-pumping techniques used to optimise the charge transfer efficiency of p- and n-channel e2v CCD204s and describe the use of trap-pumped images for on-orbit calibration and ground based image correction algorithms.

We have studied timing properties of the Amptek Silcon Drift Detectors (SDD) using pulsed X-ray source designed at NASA Goddard Space Flight Center. The proposed Neutron Star Interior Composition Explorer (NICER) mission will use 56 of these detectors as X-ray sensors in an attached payload to the International Space Station to study time variability of millisecond X-ray pulsars. Using a rastered pinhole we have measured the delay times for single X-ray photons as a function of the impact position on the detector, as well as signal rise time as a function of impact position. We find that the interdependence of these parameters allows us to determine photon position on the detector by measuring the signal rise time, and, improve the accuracy of the photon arrival time measurement.

This paper describes the use of a swept-charge device (SCD) silicon X-ray detector in a laboratory based X-ray fluorescence (XRF) facility for calculating elemental abundance ratios from planetary analogue powder samples. The facility was developed to support the Chandrayaan-1 X-ray Spectrometer (C1XS) detector development and calibration activities prior to the flight of the instrument onboard the Indian Space Research Organisation (ISRO) Chandrayaan-1 mission to the Moon in 2008. The test facility has subsequently been used to carry out XRF analysis of homogenous samples made from mixtures of MgO, Al₂O₃ and SiO₂ powders, all of grain size <44 μm, across a range of mixture ratios and at a high level of X-ray flux data in order to develop an algorithm which will allow the calculation of elemental abundance ratios. This paper also presents an analysis of XRF data collected from lunar regolith simulant JSC-1A and an Etna Basalt powder sample to enable calibration of various model parameters. The operation of the SCD, the XRF test facility, the sample preparation methodology and the process of obtaining elemental abundance ratios from planetary analogue samples using the test facility are discussed in this paper.

We developed a camera with a 264 × 264 pixel pnCCD of 48 μm size (thickness 450 μm) for X-ray and optical applications. It has a high quantum efficiency and can be operated up to 400 / 1000 Hz (noise≈ 2:5 ē ENC / ≈4:0 ē ENC). High-speed astronomical observations can be performed with low light levels. Results of test measurements will be presented. The camera is well suitable for ground based preparation measurements for future X-ray missions. For X-ray single photons, the spatial position can be determined with significant sub-pixel resolution.

Tight requirements on the Large Synoptic Survey Telescope point spread function (PSF) demand sensor contribution to PSF be both small and well characterized. The sensor PSF is determined by the lateral charge diffusion on the drift path from the photon conversion point to the gates. The maximum drift path occurs for photons converted at the window, for blue optical photons in particular. Charges generated at the window surface undergo "worst case" charge spreading and the blue optical PSF is used to characterize the sensor's PSF. Different techniques for charge diffusion characterization have been developed, each with its own systematics and measurement difficulties. A new way to measure charge diffusion using an X-ray source is presented. We demonstrate the effectiveness and limitations of our technique and discuss relation of charge diffusion value obtained with X-ray measurements to sensor PSF.

LAM is developing a high-contrast imaging testbeds for in-lab demonstration of new instrumental concepts requiring high contrast imaging: in particular, for solar and stellar coronagraphy applications. In such applications, a faint target has to be detected close to a very bright source. For these test-benches, a high-dynamic range detector is required to characterize and/or to determine the performance of a new concept. Beyond the capability to detect the target, an imaging detector has to be accurate, reliable and provide reproducible performances. In order to identify a commercial camera for the development of laboratory demonstrators working with high contrast scenes, we carried out a test campaign at the Laboratoire d’Astrophysique de Marseille (LAM) evaluating several cameras implementing different detector technologies. This paper presents the results of the test campaign, carried out at LAM, providing a quantitative comparison between the investigated technologies

A system has been designed and built for developing the technique of Digital Correlated Double Sampling (DCDS) to eliminate reset noise in CCD camera systems. It allows a wide range of DCDS methods and algorithms to be tested and is based on the CCD203 from e2v technologies. The test system is described and sub-system noise characterisation test results are presented and compared with the theoretically expected performance. Furthermore, tests based on the weighted averaging of samples are described and results presented.

Scientific CCD detectors are typically readout using the Correlated Double Sampling (CDS) technique. At low pixel rates, noise of ~2e- RMS is typically achieved. The limitation for reaching lower noise comes from the 1/f component on the output of the CCD, and this noise cannot be eliminated using CDS. A new readout technique based on a digital filter is presented here for suppressing the 1/f. Using this new technique a noise of 0.4e- is achieved.

IRS² is a Wiener-optimal approach to using all of the reference information that Teledyne’s HAWAII-2RG (H2RG) detector array provides. Using a new readout pattern, IRS² regularly interleaves reference pixels with the normal pixels during readout. This differs from conventional clocking, in which the reference pixels are read out infrequently, and only in a few rows and columns around the outside edges of the detector array. During calibration, the data are processed in Fourier space, which is close to the noise’s eigenspace. Using IRS², we have reduced the read noise of the James Webb Space Telescope (JWST) Near Infrared Spectrograph’s (NIRSpec) H2RGs by 15% compared to conventional readout. We are attempting to achieve further gains by calibrating out a recently recognized non-stationary noise component that appears at the frame rate. Teledyne’s new HAWAII- 4RGs (H4RG) build in a flexible capability to interleave reference pixels. We eagerly look forward to applying IRS² techniques to H4RGs when the opportunity arises.

We report a study of the performance of an avalanche photodiode (APD) as a function of temperature from 564 K to 74 K. The dark current at avalanche onset decreases from 564 K to 74 K by approximately a factor of 125 and from 300 K to 74K the dark current at avalanche offset is reduced by a factor of about 10. The drop would have been considerably larger if the activation energy at avalanche onset (E_a) did not also decrease with decreasing temperature. These data give us insights into how to improve the single-photon counting performance of a GaN based ADP.

Euclid is one of the M-class missions selected for the next phase of ESA’s long-term Cosmic Vision programme. The primary goal of this mission is to observe the distribution and shapes of distant galaxies, with the aim of mapping and characterising the dark energy which makes up about 70% of the universe. This will be achieved by measuring the effects of weak lensing on the captured images, in terms of the distortion caused to the elipticity of galaxy shapes [1]. The e2v CCD273 was designed for the Euclid mission and is adapted from an older design (the CCD203) with changes made to improve CTE under irradiation by solar protons. Reducing the effects of radiation damage in the image sensor will result in images which have minimal distortion. This paper is focused on the on-going development and verification of 3D device models and their integration with Monte Carlo radiation damage models. Parameters such as charge interaction volume versus signal size, pixel full well capacity, and charge transfer behaviour for both the parallel and serial registers will be discussed. The main mission goals are aimed at measuring distortion due to weak lensing, so it is important to differentiate this from distortion due to radiation damage. This work will eventually lead to a method of post processing images to remove the effects of radiation damage.

PLATO is a candidate mission for an European Space Agency M-class launch opportunity. The project aims to detect exo-planets from their transits across host stars and to characterise those stars by studying their oscillations, hence the name PLATO for, PLAnetary Transits and Oscillations of stars. In order to achieve this aim the mission proposes to fly a satellite with a focal plane of up to 34 mini-telescopes, each containing 4 large area back illuminated Charge-Coupled Devices (CCDs) to provide ultra high precision photometry. If successful, the satellite will have nearly 0.9 m² of image sensors and will be by far the largest composite detector focal plane ever flown. To meet the mission requirements e2v have developed the CCD270 which has 4510 by 4510 pixels, each pixel is 18 μm by 18 μm, in a development funded by the European Space Agency. This large area (81 mm x 81 mm) full frame image sensor is intended for precision photometry with a dynamic range in excess of 30,000. The CCD270 has been manufactured with a thinner gate dielectric and a higher buried channel dose than standard devices to increase the full well capacity in the image area. The additional advantages of the thinner gate are lower power dissipation, smaller clock voltage swing for standard channel doses and higher tolerance to ionising radiation. This paper describes the imager sensor in detail and focuses on the novel aspects of the device, package and interface.

The ESPaDOnS spectrograph at the Canada-France-Hawaii Telescope was recently upgraded to use an E2V CCD42-90 deep-depletion CCD. While changing to this device from a standard silicon CCD42-90 had many benefits such as much higher red QE and much lower fringing, it was also found that the new device exhibited persistence. After talking with E2V, a solution to the persistence was found, but this resulted in reduced resolution on the spectrograph from charge diffusion. This paper will describe the solution found to allow the detector to run with no persistence and with limited charge diffusion.

The University of Arizona Imaging Technology Laboratory (ITL) has been developing back illuminated detectors and detector technologies for several astronomical projects in recent years. These projects include the WIYN telescope One Degree Imager (ODI) mosaic of Orthogonal Transfer Array CCDs, the VIRUS detectors for the University of Texas' Hobby-Eberly Telescope Dark Energy Experiment (HETDEX), detector and packaging development for the Large Synoptic Survey Telescope (LSST), and 10kx10k and 4kx4k CCDs for several instruments. In this paper we discuss these projects with an emphasis on backside processing issues and detector characterization results which may be relevant to other groups. We will also focus packaging techniques and metrology for achieving very flat and stable focal planes. Results will include device flatness at cryogenic temperatures, process yield, photo-response non-uniformity and cosmetics, quantum efficiency, read noise, linearity, charge transfer efficiency, and photon transfer data.

The demand from the astronomical community for high resolution low noise CCDs has led to the development of the STA1600LN, a 10560 × 10560 pixel, 95mm × 95mm, full-frame CCD imager with 9×9 μ² pixels. The device improvements include noise reduction to below 3ē at 100kHz, improved quantum efficiency, as well as packaging developments for improved fill factor in mosaic systems. We provide test results from production devices, along with updates on scientific systems utilizing the STA1600 for astronomy.

The Geostationary Lightning Mapper (GLM) instrument selected to fly on the National Oceanic and Atmospheric Administration (NOAA) GOES-R Series environmental satellites has very unique requirements as compared to an imaging array. GLM's requirements to monitor lightning on a continental scale will provide new insight into the formation, distribution, morphology and evolution of storms. A 500 frame per second backside illuminated frame transfer CCD imager (STA3900A) with variable pixel size has been developed to meet these requirements. A variable pixel architecture provides a near uniform mapping of the curved surface of the earth, while 56 outputs running at 20 MHz yield greater than a 1.1 Gigapixel per second data rate with low RMS noise and high MTF. This paper will provide detailed information on design trades required. We will report CCD read noise, dark current, full well capacity, and quantum efficiency (QE).

The Reionization And Transients Infra-Red camera has been built for rapid Gamma-Ray Burst followup and will provide simultaneous optical and infrared photometric capabilities. The infrared portion of this camera incorporates two Teledyne HgCdTe HAWAII-2RG detectors, controlled by Teledyne’s SIDECAR ASICs. While other ground-based systems have used the SIDECAR before, this system also utilizes Teledyne’s JADE2 interface card and IDE development environment. Together, this setup comprises Teledyne’s Development Kit, which is a bundled solution that can be efficiently integrated into future ground-based systems. In this presentation, we characterize the system’s read noise, dark current, and conversion gain.

In ground based astronomy, mainly all designs of sky survey telescopes are limited by the requirement that the detecting surface is flat whereas the focal surface is curved. Two kinds of solution have been investigated up to now. The first one consists in adding optical systems to flatten the image surface; however this solution complicates the design and increases the system size. Somehow, this solution increases, in the same time, the weight and price of the instrument. The second solution consists in curving artificially the focal surface by using a mosaic of several detectors, which are positioned in a spherical shape. However, this attempt is dedicated to low curvature and is limited by the technical difficulty to control the detectors alignment and tilt between each others. Today we would like to propose an ideal solution which is to curve the focal plane array in a spherical shape, thanks to our monolithic process developed at CEA-LETI based on thinned silicon substrates which allows a 100% optical fill factor. Two infrared uncooled cameras have been performed, using 320 x 256 pixels and 25 μm pitch micro-bolometer arrays curved at a bending radius of 80 mm. These two micro-cameras illustrate the optical system simplification and miniaturization involved by curved focal plane arrays. Moreover, the advantages of curved detectors on the optical performances (Point Spreading Function), as well as on volume and cost savings have been highlighted by the simulation of the opto-mechanical architecture of the spectrometer OptiMOS-EVE for the European Extremely Large Telescope (E-ELT).

Several of the next generation instruments require high-resolution visible or infrared focal plane arrays that can only be achieved by building large mosaics of individual detector arrays. A significant step towards enabling these mosaics has been the introduction of the SIDECAR ASIC by Teledyne Imaging Sensors, a single chip for generating biases and clocks to the image sensor, and for digitizing up to 36 sensor outputs. To support large detector mosaics, we have developed a new control electronics approach that operates up to 32 SIDECAR ASIC / HxRG detectors in parallel. Important properties of the electronics include separately programmable voltage supplies for each ASIC with programmable over-current and over-voltage protection, synchronized operation of all ASICs, and support for post-processing of science data like co-adding of frames, sample-up-the-ramp processing, or centroiding. All ASIC and detector modes are supported, including window/guide mode operation. The electronics uses a full mode CameraLink interface to provide 680 MBytes/s of sustained bandwidth. In this paper, we present an overview of the electronics architecture, including the general computer infrastructure for data acquisition, storage and sharing. We will discuss benefits and features of the chosen approach, and present data captured using a SIDECAR ASIC and H2RG detector. The effort was funded by NASA's WFIRST project as part of an initial technology demonstration for large space-based detector mosaics.

In the frame work of the European Space Agency's Cosmic Vision program, the Euclid mission has the objective to map the geometry of the Dark Universe. Galaxies and clusters of galaxies will be observed in the visible and near-infrared wavelengths by an imaging and spectroscopic channel. For the Near Infrared Spectrometer instrument (NISP), the state-of-the-art HAWAII-2RG detectors will be used, associated with the SIDECAR ASIC readout electronic which will perform the image frame acquisitions. To characterize and validate the performance of these detectors, a test bench has been designed, tested and validated. This publication will present preliminary measurements on dark current, read noise, conversion gain and power consumption, In summary, the following results have been obtained in our system: dark current of 0.014 e^-/s/pixel at 82K; readout noise of 23 e^- for a single CDS pair and 5.4e^- for a Fowler(32); a total electric power consumption of 203 mW in LVDS (excluding I/O power) mode. The SIDECAR ASIC has also been characterized separately at room temperature. Two references voltages, VPreAmpRef1 and VrefMain, used to adjust the offset of the pre-amp DAC has been studied. The reset voltage, V_reset, was measured to have a root mean square stability of 22μV over 15 minutes and a root mean square stability value of 24μV over a 15 hours measurement period. An offset between set value and measured value of around 60mV for low set voltages has been noticed. The behavior of VPreAmpRef1 and VrefMain with a adjustable external input voltage has been conducted in order to tune these two biases to cover the desired input range with the best linearity.

MOSFIRE is a new multi-object near-infrared spectrometer for the Keck 1 telescope with a spectral resolving power of R~3500 for a 0.7″ slit (2.9 pixels). The detector is a substrate-removed 2K × 2K HAWAII 2-RG HgCdTe array from Teledyne Imaging Sensors with a cut-off wavelength of 2.5 μm and an operational temperature of 77K. Spectroscopy of faint objects sets the requirement for low dark current and low noise. MOSFIRE is also an infrared camera with a 6.9′ field of view projected onto the detector with 0.18″ pixel sampling. Broad-band imaging drives the requirement for 32-channel readout and MOSFIREs fast camera optics implies the need for a very at detector. In this paper we report the final performance of the detector selected for MOSFIRE. The array is operated using the SIDECAR ASIC chip inside the MOSFIRE dewar and v2.3 of the HxRG software. Dark current plus instrument background is measured at <0.008 ē s⁻¹ pixel⁻1 on average. Multiple Correlated Double Sampling (MCDS) and Up-The-Ramp (UTR) sampling are both available. A read noise of <5ē rms is achieved with MCDS 16 and the lowest noise of 3ē rms occurs for 64 samples. Charge persistence depends on exposure level and shows a large gradient across this detector. However, the decay time constant is always ~660 seconds. Linearity and stability are also discussed.

NIRSpec (Near Infrared Spectrograph) is one of the four science instruments of the James Webb Space Telescope (JWST) and its focal plane consists of two HAWAII-2RG sensors operating in the wavelength range 0.6−5.0μm. As part of characterizing NIRSpec, we studied the noise properties of these detectors under dark and illuminated conditions. Under dark conditions, and as already known, 1/f noise in the detector system produces somewhat more noise than can be accounted for by a simple model that includes white read noise and shot noise on integrated charge. More surprisingly, at high flux, we observe significantly lower total noise levels than expected. We show this effect to be due to pixel-to-pixel correlations introduced by signal dependent inter-pixel crosstalk, with an inter-pixel coupling factor, α, that ranges from ~ 0.01 for zero signal to ~ 0.03 close to saturation.

We present in this paper a performance characterization of an Electron Multiplication CCD (EMCCD) camera which has been deployed on the Brazilian Tunable Filter Imager (BTFI) instrument for the SOAR telescope in Chile. The BTFI instrument has two e2v CCD207 EMCCDs with a format of 1600-by-1600 pixels. The CCD207s are full-frame devices and are read out at a pixel rate of 10MHz with very low noise using an EMCCD controller (the CCD Controller for Counting Photons or CCCP for short) which was custom-built by a group based in the University of Montreal and is now commercialized by Nüvü Camēras. The first laboratory characterizations were done in Montreal in October, 2011 and the "first-light" results with the camera operating at the telescope are presented.

Observations in seeing limited imaging conditions with an extremely large telescope - such as the European Extremely Large Telescope (E-ELT) - will require large detectors and very fast cameras (around F/1.0). The correction of field curvature is a complex task, requiring numerous optical elements operating with high incidence angles. Large format (60 to 90 mm square) concave detectors with a curvature radius between 500 and 250 mm would considerably simplify the optical design, while improving image quality and cutting cost of optical components. Potential applications are not limited to astronomy exclusively. The associated advantages of curved image sensors inside (mosaicked) focal planes have been described in our paper “The challenge of highly curved monolithic imaging detectors”, presented at SPIE 2010 [1]. This paper compares in a first step important developments in the area of curving CCD and CMOS detectors using different technical approaches linked to specific thinning processes with a novel approach followed after ESO’s initial feasibility study: First results of the latter are described with a report on the chosen curving technology aimed at producing 500 to 250 mm radius of curvature silicon detectors of approximately 60 mm square format (typical astronomical 4k × 4k CCDs). The curvature technique has been developed for front-illuminated devices with the goal of extending the process to back-illuminated sensors in the near future. We will discuss the fabrication process of curving the devices as well as the difficulties encountered during development. Characterization results from a curved detector, including metrology, and electrical performance before and after curvature are presented.

Hyper Suprime-Cam (HSC)¹,² is a wide field imaging camera with the field of view (FOV) 1.5 degree diameter, which is to be installed at the prime focus of the Subaru Telescope. The large FOV is realized by the 116 2K × 4K pixels fully depleted back-illuminated CCD (FDCCD) with 15 μm pixel square. The acceptance inspection of the CCDs started around the end of 2009 and finished June 2011. We measured basic characteristics such as charge transfer efficiency (CTE), dark current, readout noise, linearity and the number of the dead column for all CCDs, and measured the quantum effciency (QE) of 21 CCDs. As a result, we confirmed exceptional quality and performance fdor all CCDs ans were able to select the best pissible 116 CCDs. We also measured the flatness of each CCD at room temperature, and optimally placed them on the focal plane plate. In this paper, we report the results of the acceptance inspection asn the installation process into the HSC dewar³,⁴.

The instrumentation group of the Herzberg Institute of Astrophysics was commissioned by the Gemini Observatory to develop a new focal plane assembly for the Gemini Multi-Object Spectrograph with an array of three deep-depletion Hamamatsu CCDs. The main objective of the upgrade is to improve the sensitivity of the instrument in the red and nearinfrared wavelengths, with the additional benefits of reduced fringing, faster readout, and better performance in the "nod and shuffle" mode. We describe what we learned about these relatively new CCDs, including several problems encountered during testing, and report on the performance of the system.

The visual imaging instrument VIS on board Euclid baselines 36 newly designed CCD273-84 devices from e2v. While these new devices have a 4kx4k format with four readout nodes, the Euclid Imaging Consortium (EIC) has performed extensive test campaigns on both irradiated and un-irradiated devices of the 4kx1k Euclid precursor variant CCD204-22. In support of the CCD development and characterization, and to enable an independent assessment of the Euclid CCDs (the procurement of which is ESA’s responsibility), ESA/ESTEC has built a test bench. This test bench allows for a flexible operation and readout of the CCDs, originally for CCD204 and shortly also for CCD273-84. It provides the basic tools for noise and gain calibration, and CTI, QE, MTF and PRNU measurements. In addition, the bench provides scanning spot illumination with a spot size well below the pixel size, for measurement of the intra-pixel response of the CCDs before and after radiation damage. Such measurements are of great importance for the characterization and modeling of the VIS instrument’s PSF, in particular to enable the prediction of the evolution of the PSF shape under the influence of the L2 radiation environment during the mission. This set-up will also allow for simulation of typical Euclid sky images in the lab. The capabilities and validation of this bench at ESA are described in this paper.

Euclid is the ESA mission to map the geometry of the dark Universe using two cosmological probes, namely Weak Lensing and Baryonic Acoustic oscillations. The visual imager, a CCD based optical imaging channel will be used to measure the shapes of galaxies in one single wide visual band spanning the wavelength range of 550-920 nm. The focal plane array supports 36 CCDs (4k×4k pixels each) with 0.101 arcsec pixel platescale, giving a geometric field of 0.55 deg². With the weak lensing technique, the mass distribution of the lensing structures can be traced back. The originally baselined CCDs were e2v CCD203-82. Following the results from a dedicated radiation damage test activity on their CCD204 variant, a new version, called 273 has been designed and made available in a front-illuminated version in April 2012. For Euclid, the accuracy with which the shape of the galaxies has to be measured is considerable: 1% and has never been demonstrated. The radiation damage effects will adversely affect this measurement and thus need to be characterized. Therefore, several test campaigns on the characterization of the CCD radiation damages for Euclid are carried out by ESA and by the Euclid Imaging Consortium. For this purpose, a test bench has been implemented at ESTEC to characterize CCD devices, with radiometric measurements, point source illumination and lab simulation of typical Euclid sky images. The preliminary results obtained at ESA on a non-irradiated front-illuminated Euclid prototype CCD 273-84-2-F16 will be shown in this article.

As part of the LSST sensor development program we have developed an advanced CCD emulator for testing new multichannel readout electronics. The emulator, based on an Altera Stratix II FPGA for timing and control, produces 4 channels of simulated video waveforms in response to an appropriate sequence of horizontal and vertical clocks. It features 40MHz, 16-bit DACs for reset and video generation, 32MB of image memory for storage of arbitrary grayscale bitmaps, and provision to simulate reset and clock feedthrough ("glitches") on the video channels. Clock inputs are qualified for proper sequences and levels before video output is generated. Binning, region of interest, and reverse clock sequences are correctly recognized and appropriate video output will be produced. Clock transitions are timestamped and can be played back to a control PC. A simplified user interface is provided via a daughter card having an ARM M3 Cortex microprocessor and miniature color LCD display and joystick. The user can select video modes from stored bitmap images, or flat, gradient, bar, chirp, or checkerboard test patterns; set clock thresholds and video output levels; and set row/column formats for image outputs. Multiple emulators can be operated in parallel to simulate complex CCDs or CCD arrays.

The PAU Camera (PAUCam) [1,2] is a wide field camera that will be mounted at the corrected prime focus of the William Herschel Telescope (Observatorio del Roque de los Muchachos, Canary Islands, Spain) in the next months. The focal plane of PAUCam is composed by a mosaic of 18 CCD detectors of 2,048 x 4,176 pixels each one with a pixel size of 15 microns, manufactured by Hamamatsu Photonics K. K. This mosaic covers a field of view (FoV) of 60 arcmin (minutes of arc), 40 of them are unvignetted. The behaviour of these 18 devices, plus four spares, and their electronic response should be characterized and optimized for the use in PAUCam. This job is being carried out in the laboratories of the ICE/IFAE and the CIEMAT. The electronic optimization of the CCD detectors is being carried out by means of an OG (Output Gate) scan and maximizing it CTE (Charge Transfer Efficiency) while the read-out noise is minimized. The device characterization itself is obtained with different tests. The photon transfer curve (PTC) that allows to obtain the electronic gain, the linearity vs. light stimulus, the full-well capacity and the cosmetic defects. The read-out noise, the dark current, the stability vs. temperature and the light remanence.

We report on the status of the detector system for the Robert Stobie Spectrograph Near Infrared Arm (RSS-NIR) for the Southern African Large Telescope (SALT). The detector is a HAWAII-2RG array with a 1.7 μm cutoff wavelength. The controller incorporates a Teledyne cryogenic SIDECAR ASIC board inside the dewar and an FPGA interface card, developed by the Inter-University Centre for Astronomy and Astrophysics (IUCAA), outside the dewar. Data acquisition software written by IUCAA runs under a Linux operating system and communicates to the detector system through USB to fiber optic converters for electrical isolation on the telescope. System characterization is performed at the University of Wisconsin RSS-NIR Lab in a liquid nitrogen cooled test dewar. The test dewar contains a thermal control system that emulates operation of the cryocooler used in the instrument dewar and maintains a stable detector operating temperature of 120 K. Light is provided to the detector with near infrared LEDs mounted inside the dewar. We present preliminary data on system noise and plans for further characterization tests.

A CCD test-bench has been built at the Universidad Complutense´s LICA laboratory. It is initially intended for commissioning of the MEGARA¹ (Multi-Espectrógrafo en GTC de Alta Resolución para Astronomía) instrument but can be considered as a general purpose scientific CCD test-bench. The test-bench uses an incandescent broad-band light source in combination with a monochromator and two filter wheels to provide programmable narrow-band illumination across the visible band. Light from the monochromator can be directed to an integrating sphere for flat-field measurements or sent via a small aperture directly onto the CCD under test for high accuracy diode-mode quantum efficiency measurements. Point spread function measurements can also be performed by interposing additional optics between sphere and the CCD under test. The whole system is under LabView control via a clickable GUI. Automated measurement scans of quantum efficiency can be performed requiring only that the user replace the CCD under test with a calibrated photodiode after each measurement run. A 20cm diameter cryostat with a 10cm window and Brooks Polycold PCC closed-cycle cooler also form part of the test-bench. This cryostat is large enough to accommodate almost all scientific CCD formats has initially been used to house an E2V CCD230 in order to fully prove the test-bench functionality. This device is read-out using an Astronomical Research Camera controller connected to the UKATC´s UCAM data acquisition system.

In the frame work of the European Space Agency's Cosmic Vision program, the Euclid mission has the objective to map the geometry of the Dark Universe. Galaxies and clusters of galaxies will be observed in the visible and near-infrared wavelengths by an imaging and spectroscopic channel. For the Near Infrared Spectrometer instrument (NISP), the state-of-the-art HAWAII-2RG detectors will be used, associated with the SIDECAR ASIC readout electronic which will perform the image frame acquisitions. To characterize and validate the performance of these detectors, a test bench has been designed, tested and validated. This publication describes the pre-tests performed to build the set up dedicated to dark current measurements and tests requiring reasonably uniform light levels (such as for conversion gain measurements). Successful cryogenic and vacuum tests on commercial LEDs and photodiodes are shown. An optimized feed through in stainless steel with a V-groove to pot the flex cable connecting the SIDECAR ASIC to the room temperature board (JADE2) has been designed and tested. The test set up for quantum efficiency measurements consisting of a lamp, a monochromator, an integrating sphere and set of cold filters, and which is currently under construction will ensure a uniform illumination across the detector with variations lower than 2%. A dedicated spot projector for intra-pixel measurements has been designed and built to reach a spot diameter of 5 μm at 920nm with 2nm of bandwidth [1].

Even though the last instruments built with the previous generation of MPIA-ROE are offering in the meantime most of the standard readout modes, the current generation ROE is based on the experience of the last years, and besides other properties like small volume, more channels, less power consumption, etc., it will also allow extended readout modes in the near future by using the detector engineering and data interfaces of GEIRS. The Hawaii-2-RG detector has a large amount of operational flexibilities to support extended readout modes. With special properties in the pattern generator of the ROE and in GEIRS, new extended readout modes can be implemented identically for the Hawaii-2 and the Hawaii-2RG in multichannel mode. This paper presents an overview of the standard readout schemes and describes additional selectable options, offered idle-modes, and some new extended modes available with this generation of MPIA-ROE for the next instruments and instrument updates using HgCdTe-detectors. During the last 15 years MPIA has built 8 sets of previous readout electronics (ROE) for 8 astronomical infrared instruments^1-8. The generic infrared camera software GEIRS (spoken like 'cheers') is used in these instruments either as a pure readout software layer or as an overall control software for IR-instruments, the last case in particular with instruments for the Calar-Alto observatory in Spain.

The unique linear avalanche properties of HgCdTe preserve the Poisson statistics of the incoming photons, opening up new opportunities for GHz bandwidth LADAR and space communications applications. Raytheon has developed and previously reported ₍₁₎ unique linear mode photon counting arrays based on combining advanced HgCdTe linear mode APDs with their high gain SB415B readout. Their use of HgCdTe APDs preserves the Poisson statistics of the incoming photons, enabling (noiseless) photon counting. This technology is of great potential interest to infrared astronomy but requires extension of noiseless linear HgCdTe avalanching down to much lower bandwidths (100 to 0.001 Hz) with corresponding reductions in dark count rate. We have hybridized the SB415B readout to SWIR HgCdTe APDs optimized for low dark count rate and have characterized their photon counting properties at bandwidths down to 1 KHz. As bandwidth is reduced, the performance becomes limited by the intrinsic properties of the SB415B readout, particularly readout glow, stability and 1/f noise. We report the results of these measurements and the status of hybrid arrays utilizing a newly developed readout which draws on Raytheon’s astronomical readout heritage, specifically the Virgo charge integrating source follower, as a path to much lower dark count rate photon counting operation.

Quad photoreceivers, namely a 2 x 2 array of p-i-n photodiodes followed by a transimpedance amplifier (TIA) per diode, are required as the front-end photonic sensors in several applications relying on free-space propagation with position and direction sensing capability, such as long baseline interferometry, free-space optical communication, and biomedical imaging. It is desirable to increase the active area of quad photoreceivers (and photodiodes) to enhance the link gain, and therefore sensitivity, of the system. However, the resulting increase in the photodiode capacitance reduces the photoreceiver's bandwidth and adds to the excess system noise. As a result, the noise performance of the front-end quad photoreceiver has a direct impact on the sensitivity of the overall system. One such particularly challenging application is the space-based detection of gravitational waves by measuring distance at 1064 nm wavelength with ~ 10 pm/√Hz accuracy over a baseline of millions of kilometers. We present a 1 mm diameter quad photoreceiver having an equivalent input current noise density of < 1.7 pA/√Hz per quadrant in 2 MHz to 20 MHz frequency range. This performance is primarily enabled by a rad-hard-by-design dualdepletion region InGaAs quad photodiode having 2.5 pF capacitance per quadrant. Moreover, the quad photoreceiver demonstrates a crosstalk of < -45 dB between the neighboring quadrants, which ensures an uncorrected direction sensing resolution of < 50 nrad. The sources of this primarily capacitive crosstalk are presented.

We have demonstrated advances in mosaic hybridization that will enable very large format far-infrared detectors. Specifically we have produced electrical detector models via mosaic hybridization yielding superconducting circuit paths by hybridizing separately fabricated sub-units onto a single detector unit. The detector model was made on a 100mm diameter wafer while four model readout quadrant chips were made from a separate 100mm wafer. The individually fabricated parts were hybridized using a flip-chip bonder to assemble the detector-readout stack. Once all of the hybridized readouts were in place, a single, large and thick silicon substrate was placed on the stack and attached with permanent epoxy to provide strength and a Coefficient of Thermal Expansion match to the silicon components underneath. Wirebond pads on the readout chips connect circuits to warm readout electronics; and were used to validate the successful superconducting electrical interconnection of the model mosaic-hybrid detector. This demonstration is directly scalable to 150 mm diameter wafers, enabling pixel areas over ten times the area currently available.

EMIR is the NIR imager and multiobject spectrograph being built as a common user instrument for the GTC and it is currently entering in the integration and verification phase at system level. EMIR is being built by a Consortium of Spanish and French institutes led by the IAC. In this paper we describe the readout modes of EMIR detector, a Hawaii2 FPA, after two full calibrations campaigns. Besides the standard set of modes (reset-read, CDS, Fowler, Follow-up the ramp), the modified SDSU-III hardware and home made software will also offer high dynamic range readout modes, which will improve the ability of the instrument to sound densely populated areas which often are made of objects with large differences in brightness. These new high dynamic range modes are: single readout with very short integration time, window mode and combination of both. The results show that the new modes behave linearly with different exposition times, improve the maximum frame rate and increase the saturation limit in image mode for EMIR instrument.

Solar-C is the third generation solar observatory led by JAXA. The accepted ‘Plan-B’ payload calls for a radiation-hard solar-staring photon-counting x-ray spectrometer. CMOS APS technology offers advantages over CCDs for such an application such as increased radiation hardness and high frame rate (instrument target of 1000 fps). Looking towards the solution of a bespoke CMOS APS, this paper reports the x-ray spectroscopy performance, concentrating on charge collection efficiency and split event analysis, of two baseline e2v CMOS APSs not designed for x-ray performance, the EV76C454 and the Ocean Colour Imager (OCI) test array. The EV76C454 is an industrial 5T APS designed for machine vision, available back and front illuminated. The OCI test arrays have varying pixel design across the chips, but are 4T, back illuminated and have thin low-resistivity and thick high-resistivity variants. The OCI test arrays’ pixel variants allow understanding of how pixel design can affect x-ray performance.

Cadmium-Zinc-Telluride (CZT) is thought to be a primary work horse for hard X-ray astronomy in future. Due to the relatively large band-gap, it offers near room temperature operation while maintaining much better energy resolution then scintillator detectors operating in similar energy range. Further, CZT detectors are available in the form of pixilated detectors with area up to few cm² and hence it is possible to realize very large detector area by having an array of such pixilated CZT detectors. However, it is well known that the energy spectrum of mono-energetic X-ray measured by CZT detectors does not have a Gaussian shape but has significant low-energy tail. This is mainly due to relatively poor mobility and small life time of the charge carriers, particularly of holes, in the CZT crystals. Thus, in order to understand spectral response for a large array of CZT detectors consisting of multiple elements / pixels, it is essential to characterize the mobility-lifetime products of charge carriers for each individual elements / pixels. Here we present experimental measurements of charge carrier mobility-lifetime products for large sample of multi-pixel CZT detectors. The mobility-lifetime products are measured by simultaneously fitting a ‘CZT line’ model to pixel wise spectra of 122 keV X-rays from ⁵⁷Co at three different bias voltages. These were carried out as a part of selection of CZT detector modules for the “High Energy X-ray spectrometer (HEX)” onboard Indian moon mission – Chandrayaan-1.

We present the formulation of an analytical model which simulates charge transport in Swept Charge Devices (SCDs) to understand the nature of the spectral redistribution function (SRF). We attempt to construct the energy-dependent and position dependent SRF by modeling the photon interaction, charge cloud generation and various loss mechanisms viz., recombination, partial charge collection and split events. The model will help in optimizing event selection, maximize event recovery and improve spectral modeling for Chandrayaan-2 (slated for launch in 2014). A proto-type physical model is developed and the algorithm along with its results are discussed in this paper.

We are presenting the results of our ongoing efforts to develop a new type of focal plane detector for the 10 to 100 keV band with an energy resolution of 0.1 %. The device will measure energy and position by using microwave kinetic inductance detectors (MKIDs) to sense athermal phonons created by photon absorption in a dielectric substrate. We have fabricated a proof-of-concept detector of size 2 cm × 2 cm × 1 mm on silicon, which has demonstrated a baseline energy resolution of = 0.38 keV and = 0.55 keV at 30 keV.

EMCCDs have been used in the astronomical observations in many ways. Recently we develop a camera using an EMCCD TX285. The CCD chip is cooled to −100°C in an LN2 dewar. The camera controller consists of a driving board, a control board and a temperature control board. Power supplies and driving clocks of the CCD are provided by the driving board, the timing generator is located in the control board. The timing generator and an embedded Nios II CPU are implemented in an FPGA. Moreover the ADC and the data transfer circuit are also in the control board, and controlled by the FPGA. The data transfer between the image workstation and the camera is done through a Camera Link frame grabber. The software of image acquisition is built using VC++ and Sapera LT. This paper describes the camera structure, the main components and circuit design for video signal processing channel, clock driver, FPGA and Camera Link interfaces, temperature metering and control system. Some testing results are presented.

PAUCam is a new camera for studying the physics of the accelerating universe. The camera will consist of eighteen 2Kx4K HPK CCDs: sixteen for science and two for guiding. The camera will be installed at the prime focus of the WHT (William Herschel Telescope). In this contribution, the architecture of the readout electronics system is presented. Back- End and Front-End electronics are described. Back-End consists of clock, bias and video processing boards, mounted on Monsoon crates. The Front-End is based on patch panel boards. These boards are plugged outside the camera feed-through panel for signal distribution. Inside the camera, individual preamplifier boards plus kapton cable completes the path to connect to each CCD. The overall signal distribution and grounding scheme is shown in this paper.

The Dark Energy Camera (DECam) was developed for use by the Dark Energy Survey (DES). The camera will be installed in the Blanco 4M telescope at the Cerro Tololo Inter-American Observatory (CTIO) and be ready for observations in the second half of 2012. The focal plane consists of 62 2×4K and 12 2×2K fully depleted CCDs. The camera provides a 3 sq. degree view and the survey will cover a 5000 sq. degree area. The camera cage and corrector have already been installed. The development of the electronics to readout the focal plane was a collaborative effort by multiple institutions in the United States and in Spain. The goal of the electronics is to provide readout at 250 kpixels/second with less than 15erms noise. Integration of these efforts and initial testing took place at Fermi National Accelerator Laboratory. DECam currently resides at CTIO and further testing has occurred in the Coudé room of the Blanco. In this paper, we describe the development of the readout system, test results and the lessons learned.

Hyper Suprime-Cam (HSC) employs 116 pieces of 2k×4k fully-depleted CCD with a total of 464 signal outputs to cover the 1.5 degrees diameter field of view. The readout electronics was designed to achieve ~5 e of the readout noise and 150000 e of the fullwell capacity with 20 seconds readout time. Although the image size exceeds 2G Bytes, the readout electronics supports the 10 seconds readout time for the entire CCDs continuously. All of the readout electronics and the CCDs have already been installed in the camera dewar. The camera has been built with equipment such as coolers and an ion pump. We report the readout performance of all channels of the electronics extracted from the recent test data.

The Reionization And Transients InfraRed (RATIR) camera has been built for rapid Gamma-Ray Burst (GRB) followup and will provide quasi-simultaneous imaging in ugriZY JH. The optical component uses two 2048 × 2048 pixel Finger Lakes Imaging ProLine detectors, one optimized for the SDSS u, g, and r bands and one optimized for the SDSS i band. The infrared portion incorporates two 2048 × 2048 pixel Teledyne HgCdTe HAWAII-2RG detectors, one with a 1.7-micron cutoff and one with a 2.5-micron cutoff. The infrared detectors are controlled by Teledyne's SIDECAR (System for Image Digitization Enhancement Control And Retrieval) ASICs (Application Specific Integrated Circuits). While other ground-based systems have used the SIDECAR before, this system also utilizes Teledyne's JADE2 (JWST ASIC Drive Electronics) interface card and IDE (Integrated Development Environment). Here we present a summary of the software developed to interface the RATIR detectors with Remote Telescope System, 2nd Version (RTS2) software. RTS2 is an integrated open source package for remote observatory control under the Linux operating system and will autonomously coordinate observatory dome, telescope pointing, detector, filter wheel, focus stage, and dewar vacuum compressor operations. Where necessary we have developed custom interfaces between RTS2 and RATIR hardware, most notably for cryogenic focus stage motor drivers and temperature controllers. All detector and hardware interface software developed for RATIR is freely available and open source as part of the RTS2 distribution.

GIANO is a high resolution (R≃50,000) cryogenic IR spectrograph covering the 0.95-2.5μm wavelengths range. It is equipped with a Hawaii-II PACE array. We present the main results and performances of the detector and acquisition system. We also describe a few special features which have been developed to optimize the noise performances and minimize spurious effects intrinsic to the detector, such as reset anomaly, cross-talking and radioactive-like events.

The increasing use of many and different kind of light detectors to acquire, monitor and control various aspects of the observation imposes the need to standardize the acquisition and processing of images and data. While scientific image acquisition systems usually include a complex controller, some less demanding subsystems require the development of electronics and software to read the image. Most of the times these image detectors are rather small and high speed is of no concern, so controllers need not to be fast; take for instance a telescope guider. With these directives in mind, in this work we present a very simple image acquisition system based on a Texas Instruments microcontroller of the family MSP430 and a serial static memory as a standard instrumentation starting for small image acquisition controllers.

The readout noise of a H2RG HgCdTe NIR detector from Teledyne is measured at a temperature T=100K. In a previous work, we have analysed the evolution of the readout noise as a function of the number of reads in terms of the frequency power spectrum of the noise with our in-house hybrid readout electronics. The new measurements with the SIDECAR ASIC provided by Teledyne Imaging Sensors are compared to the previous ones. The noise power spectrum found can be used in a wide range of timing conditions and allows to predict the 1/f effects.

The background minimization is a science-driven necessity in order to reach deep sensitivity levels in the hard X-ray band, one of the key scientific requirements for hard X-ray telescopes (e.g. NuSTAR, ASTRO-H). It requires a careful modeling of the radiation environment and new concepts of shielding systems. We exploit the Bologna Geant4 Multi-Mission Simulator (BoGEMMS) features to evaluate the impact of the Low Earth Orbit (LEO) radiation environment on the prompt background level for a hybrid Si/CdTe soft and hard X-ray detection assembly and a combined active and passive shielding system. For each class of particles, the spectral distribution of the background flux is simulated, exploring the effect of different materials (plastic vs inorganic active scintillator) and configurations (passive absorbers enclosing or surrounded by the active shielding) on the background count rate. While protons are efficiently removed by the active shielding, an external passive shielding causes the albedo electrons and positrons to be the primary source of background. Albedo neutrons are instead weakly interactive with the active shielding, and they cause an intense background level below 10 keV via elastic scattering. The best shielding configuration in terms of background and active shielding count rates is given by an inorganic scintillator placed inside the passive layers, with the addition of passive material to absorb the intense fluorescence lines of the active shielding and avoid escape peaks on the CdTe detector.

The Chandrayaan-1 X-ray Spectrometer (C1XS) was launched onboard the Indian Space Research Organisation (ISRO) Chandrayaan-1 lunar mission in October 2008. The instrument consisted of 24 swept-charge device silicon X-ray detectors providing a total collecting area of ~24 cm^2, corresponding to a 14° field of view (FWHM), with the ability to measure X-rays from 0.8 – 10 keV. During the 10 months the spacecraft was located in orbit around the Moon a number of solar flare X-ray events were detected, along with calibration data from X-ray sources housed inside the movable door of the instrument. This paper presents a further study of the degradation in spectral resolution of the measured X-ray calibration lines, adding a final calibration point towards the end of mission lifetime to the known results from the midpoint of the mission, giving a more detailed analysis of the extent of the radiation damage. The radiation environment the detectors were subjected to is discussed in light of the actual radiation damage effects on the spectral resolution observed in flight.

At SRON we are developing the Frequency Domain Multiplexing (FDM) for the read-out of the TES-based detector array for the future infrared and X-ray space mission. We describe the performances of a multiplexer designed to increase the experimental throughput in the characterisation of ultra-low noise equivalent power (NEP) TES bolometers and high energy resolving power X-ray microcalorimeters arrays under ac and dc bias. We discuss the results obtained using the TiAu TES bolometers array fabricated at SRON with measured dark NEP below 5 · 10⁻¹⁹W/ √ Hz and saturation power of several fW.

The HAWC Project is a very high-energy gamma-ray observatory under construction at the Sierra Negra volcano (4100 meters above sea level) in the Pico de Orizaba National Park located in central Mexico. HAWC will reuse the 900 Hamamatsu R5912 photomultipliers (PMTs) from Milagro Observatory for the 300 Water Cherenkov Detectors. In order to characterize their present performance it is necessary to scan the active area of the photocathode by measuring its efficiency and gain. A characterization system was designed and manufactured to achieve an automated measurement of over 100 points distributed on the PMT active spherical surface. Preliminary results show the variation of QE of PMTs with respect of the position of incoming photons, as well as the changes in the PMTs response due to the Earth's magnetic field and gain vs. high voltage. The system allows automated PMT characterization improving its performance, reliability, precision and repeatability. In this work we present the characterization system and preliminary results on the PMT efficiency.

BoGEMMS, (Bologna Geant4 Multi-Mission Simulator) is a software project for fast simulation of payload on board of scientific satellites for prompt background evaluation that has been developed at the INAF/IASF Bologna. By exploiting the Geant4 set of libraries, BoGEMMS allows to interactively set the geometrical and physical parameters (e.g. physics list, materials and thicknesses), recording the interactions (e.g. energy deposit, position, interacting particle) in NASA FITS and CERN root format output files and filtering the output as a real observation in space, to finally produce the background detected count rate and spectra. Four different types of output can be produced by the BoGEMMS capturing different aspects of the interactions. The simulator can also run in parallel jobs and store the results in a centralized server via xrootd protocol. The BoGEMMS is a multi-mission tool, generally designed to be applied to any high-energy mission for which the shielding and instruments performances analysis is required.

Devices in low Earth orbit are particularly susceptible to the cumulative effects of radiation damage and the Hubble Space Telescope Wide Field Camera 3 (HST/WFC3) UVIS detectors, installed on HST in May 2009, are no exception. Such damage not only generates new hot pixels but also generates charge traps which degrade the charge transfer efficiency (CTE), causing a loss in source flux as well as a systematic shift in the object centroid as the trapped charge is slowly released during readout. Based on an analysis of internal and external monitoring data, we provide an overview of the consequences of the ~3 years of radiation damage to the WFC3 CCD cameras. The advantages and disadvantages of available mitigation options are discussed, including use of the WFC3 post-flash and charge injection modes now available to observers, and the status of an empirical pixel-based correction similar to the one adopted for the HST Advanced Camera for Surveys (ACS).