The space-based multi-band astronomical variable objects monitor (SVOM) is a Chinese–French mission due to be launched in 2023. It is composed of four space borne instruments: ECLAIRs, for detecting x-ray and gamma-ray transients; GRM, a gamma-ray spectrometer; VT, a visible telescope and the Microchannel X-ray Telescope (MXT). The MXT’s main goal is to precisely localize, and spectrally characterize x-ray afterglows of gamma-ray bursts. The MXT is a narrow-field-optimised lobster eye x-ray focusing telescope comprising an array of 25 square micro pore optics (MPOs), with a detector-limited field of view of ∼1 square degree, working in the energy band 0.2-10 keV. The SVOM flight model (FM) MXT optic (MOP) was designed, built and initially tested at the University of Leicester and a full calibration of the MOP was completed at the PANTER facility (MPE). It was then integrated in to the full proto flight model (PFM) MXT instrument before it returned to PANTER for the PFM MXT’s full calibration. We present the optic performance as part of the full FM MXT instrument calibration. The response of the telescope was studied at 11 energies from C-K (0.28 keV) to Ge-K (9.89 keV), including measurements of the effective area and the PSF size and shape. The focal length of the instrument was determined and details of the modelling and analysis used to predict the performance are presented. The measurements demonstrate that the actual effective area and PSF are in good agreement with the modelling.
The Lobster Eye X-ray Telescope (LEXT) is one of the payloads on-board the Gamow Explorer, which will be proposed to the 2021 NASA Explorer MIDEX opportunity. If approved, it will be launched in 2028, and is optimised to identify high-z Gamma Ray Bursts (GRBs) and enable rapid follow-up. The LEXT is a two module, CCD focal plane, large field of view telescope utilising Micro Pore Optics (MPOs) over a bandpass of 0.2 - 5 keV. The geometry of the MPOs comprises a square packed array of microscopic pores with a square cross-section, arranged over a spherical surface with a radius of curvature of 600 mm, twice the focal length of the optic, 300 mm. Working in the photon energy range 0.2 - 5 keV, the optimum L/d ratio (length of pore L and pore width d) is 60, and is constant across the whole optic aperture. This paper details the baseline design for the LEXT optic in order to full the science goals of the Gamow mission. Extensive ray-trace analysis has been undertaken and we present the development of the optic design along with the optimisation of the field of view, effective area and focal length using this analysis. Investigations as to the ideal MPO characteristics, e.g. coatings, pore size, etc., and details of avenues for further study are also given.
The Soft X-ray Imager instrument on the ESA THESEUS mission will provide high-energy imaging and spectroscopy observations of fast transients, providing significant steps forward in our understanding and characterisation of the early Universe. The instrument will utilise high performance microchannel plate optics (MPOs) and some of the first X-ray optimised CMOS devices to be used for space applications. The instrument team are currently developing a flight-like prototype instrument in order to enable full and appropriate characterisation of the instrument, and in particular the performance of candidate detectors. Here we present early results from the focal plane requirement study programme (including performance modelling and trade-off studies).
Einstein Probe is a Chinese Academy of Science (CAS) mission due for launch at the end of 2022 with its primary goals to discover high-energy transients and monitor variable objects. The mission consists of two instruments, the Wide field X-ray Telescope (WXT), a lobster eye X-ray telescope consisting of twelve identical modules; and the Follow-up X-ray Telescope (FXT), which is a traditional Wolter X-ray telescope, which is jointly developed by CAS, the European Space Agency (ESA) and the Max Planck Institute for Extraterrestrial Physics (MPE). Each of the WXT modules comprise of 36 micro pore optics (MPOs), with a 375 mm focal length, a field of view of more than 3600 square degrees, a goal of 5 arcmin resolution and working in the energy range of 0.5-4 keV. As part of the collaboration between CAS and ESA, the University of Leicester (UoL) is acting as a testing facility and repeatability check for several elements of the WXT optic development. This includes calibration of individual MPOs, temperature measurements on a prototype module, calibration of a qualification module and full calibration of one of the flight module optics. The majority of these tests will be performed in the two X-ray facilities at the University of Leicester, the Tunnel Test Facility (TTF) and the Vertical Test Facility (VTF). Presented here are details of the tests carried out and the results obtained from the first batch of individual MPOs and the plan for the thermal tests of the prototype in the TTF.
The Transient High Energy Sources and Early Universe Surveyor is an ESA M5 candidate mission currently in Phase A, with Launch in ∼2032. The aim of the mission is to complete a Gamma Ray Burst survey and monitor transient X-ray events. The University of Leicester is the PI institute for the Soft X-ray Instrument (SXI), and is responsible for both the optic and detector development. The SXI consists of two wide field, lobster eye X-ray modules. Each module consists of 64 Micro Pore Optics (MPO) in an 8 by 8 array and 8 CMOS detectors in each focal plane. The geometry of the MPOs comprises a square packed array of microscopic pores with a square cross-section, arranged over a spherical surface with a radius of curvature twice the focal length of the optic. Working in the photon energy range 0.3-5 keV, the optimum L/d ratio (length of pore L and pore width d) is upwards of 50 and is constant across the whole optic aperture for the SXI. The performance goal for the SXI modules is an angular resolution of 4.5 arcmin, localisation accuracy of ∼1 arcmin and employing an L/d of 60. During the Phase A study, we are investigating methods to improve the current performance and consistency of the MPOs, in cooperation with the manufacturer Photonis France SAS. We present the optics design of the THESEUS SXI modules and the programme of work designed to improve the MPOs performance and the results from the study.
We are entering a new era for high energy astrophysics with the use of new technology to increase our ability to both survey and monitor the sky. The Soft X-ray Imager (SXI) instrument on the THESEUS mission will revolutionize transient astronomy by using wide-field focusing optics to increase the sensitivity to fast transients by several orders of magnitude. The THESEUS mission is under Phase A study by ESA for its M5 opportunity. THESEUS will carry two large area monitors utilizing Lobster-eye (the SXI instrument) and coded-mask (the XGIS instrument) technologies, and an opticalIR telescope to provide source redshifts using multi-band imaging and spectroscopy. The SXI will operate in the soft (0.3- 5 keV) X-ray band, and consists of two identical modules, each comprising 64 Micro Pore Optics and 8 large-format CMOS detectors. It will image a total field of view of 0.5 steradian instantaneously while providing arcminute localization accuracy. During the mission, the SXI will find many hundreds of transients per year, facilitating an exploration of the earliest phase of star formation and comes at a time when multi-messenger astronomy has begun to provide a new window on the universe. THESEUS will also provide key targets for other observing facilities, such as Athena and 30m class ground-based telescopes.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.