The micro-tomography endstation at Taiwan Photon Source (TPS) utilizes an efficient design that incorporates a high-flux source, automated pre-alignment, automated sample loading/unloading and a sample storage system resulting in highly efficient operation. In double crystal monochromator (DCM) mode, the sample can be scanned in full resolution within 2 minutes which Includes loading sample, positioning, scan, and unloading sample, with up to 880 samples continuously scanned in the queue. This endstation was opened to user at 2022. This presentation will also cover the new nano-CT endstation which will be ready in 2024.
In Taiwan photon source facilities, soft x-ray beamlines are equipped with self-developed active high-precision mirrors or gratings. It is crucial to establish more advanced optical surface metrology instruments to satisfy the demands of optical production, installation, and testing in synchrotron optics. A long trace profiler (LTP) is an instrument used to measure the optical surface’s slope. This assists in monitoring the installation processes of optical instruments to ensure that the final optical components satisfy the required specifications in terms of quality. In this study, we propose a new air-bearing slide design to achieve nanometer-level precision for the LTP. This new design replaces ceramic and granite structures and addresses rail deformation and surface imperfections. This LTP features a specially designed bendable linear slide comprising four airbrushes, two shafts, and eight end mounts. The motion stage, supported and guided by four airbrushes against two parallel steel shafts, carries the optical head. End mounts are installed on the tilting stage at both ends, using flexure guides with manually adjusted screws and fine-tuning piezo. The rail system can be bent to a third-order polynomial rail profile to compensate for the effect of gravity when moving the optical head, enabling the achievement of the desired rail pitch variation within a distance of 400 mm with 2.5 μrad (RMS). To further enhance the precision, dynamic correction methods can be employed by utilizing PZT actuators and bender mechanisms. These mechanisms enabled rail pitch variation as low as 0.2 μrad (RMS).We introduce a new design for an air-bearing slide and its corresponding performance. This slide design is employed in LTP measurements. The outcomes of our study demonstrate a correlation between the observed results and the rail pitch profile.
This study is to design glass windows for soft X-ray mirror cleaning by UV light. The soft X-ray mirror will operate in the synchrotron radiation light source for several months, and the mirror surface will be covered with a carbon layer. Soft X-ray mirror cleaning uses UV light on the mirror surface and adds a little oxygen to the vacuum chamber. The carbon will be cleaned by UV light and oxygen. Thus, mirror cleaning is needed to design narrow and long windows to let the UV light arrive at the mirror. In the mirror mount in the original design, the bolt joint force causes the mirror to break. Therefore, this study cut the mount's four corners to absorb the bolt joint deformation, not to transfer to the window. A 2 mm diameter tin wire seals the window mount and successfully compensating the bolt joint forces caused the vacuum chamber and window mount deformation. The simulation result shows that this design can make success decline by 28% maximum deformation. The window mounting test is also sealing the achieve 5.5 E-11 mbar l/s.
This study is trying to design the thermal load effect on the soft x-ray beamline first mirror from ID (Insertion Device).
The beamline first mirror is HFM (Horizontal Focus Mirror), the HFM need to absorb the thermal energy, soft X-ray the footprint size om HFM is 120*5.2 mm, the thermal power is about 270 W.
The HFM cooling by the water pipe mounted on the thermal fin, mirror and thermal fin contact by Gallium–Indium alloy. The HFM thermal fin's Gallium–Indium alloy seal by nickel tube avoids leaking in the vacuum chamber.
The HFM thermal fin design can cooling mirror backside and part of frontside, and the HFM thermal bump need small than 10u rad.
The small radius x-ray mirror in the interferometer stitching measurement is needed high angle resolution rotation stage to get reliable angle information. The rotation stage rotary range requirement is not wide, because of the X-ray mirror radius generally large than 200M, and the mirror length small than 1.2M. The angle resolution is needed high resolution, therefore, in interferometer stitching measurement, the interferogram is easily affected by the rotation angle difference. Thus, this study is to design a small angle traveling range (rotation angle maximum ± 1.5 degrees), high angle resolution (10 nrad.), and high loading capacity (loading maximum 75 Kg) rotation stage, the rotation mechanism is applied pivot bearing to get high-resolution rotation angle. The rotation stage design is finished, this article discusses system assembly and test.
To achieve an ultrahigh-resolution for soft X-ray beamlines, the slope error of a highly precise grating is required on the level of 0.1 μrad root-mean-square (RMS) under thermal loading. To realize the goal, a specially designed 25-actuator optical surface bender for the gratings and mirrors is developed and operated at Taiwan Photon Source (TPS) [1]. In this paper, the construction and operation of the in situ LTP measuring system is described[2]. This LTP consists of a switchable optical reflection system that let the LTP can switch to measure horizontal or vertical mounting mirrors/gratings in the beamline. The other is a low optical distortion and bakeable to 120 ˚C glass viewport which is used for the ultra-high vacuum[3,4] interface for the beamlines optics and LTP. The surface slope error being reduced down to 0.1 and 0.15 μrad (RMS) by the 25-actuator bender without/with the glass viewport as verified by the in situ LTP measurements in the beamline.
Long trace profiler (LTP) is used to measure the large radius mirror surface profile. The in-situ LTP can be used to measure the X-ray mirror of an adaptive mirror bending system inside the vacuum chamber. In this study, the in-situ LTP measure head is outside of vacuum chamber. Therefore, the vacuum chamber and window glass thermal effect can introduce errors into the measurement results. This study calculated temperature distribution and deformation using the finite element method (FEM) software and calculate incident ray through the window glass. The incident ray through window glass with thermal gradient could increase optical path difference (OPD). The calculation resulted in an evaluation of in-situ LTP measurement error by thermal deformation.
The goal of an in situ Long Trace Profiler (LTP) is to adjust the mirror to 0.1 μrad Root Mean Square (RMS) under thermal load. Here we introduce the measurement configuration for in situ LTP. To avoid lens aberration, the moving optical head keeps the optical paths constant, and the reference beam is used to the correct of the unavoidable air bearing errors. The window glass in this test has a rather high optical quality, with a flatness of 1/150 (RMS) over 120 × 20 mm. The optical quality of the window was specified to be ± 1 μrad slope distortion in an aperture length of 100 mm. The window glass deformation for the air pressure was calculated by the Finite Element Method (FEM) software (ANSYS). The window glass deformation results can be fitting by the Zernike polynomial, and then bring it into the sequential optical ray tracing software (ZEMAX), and evaluating the window glass effect on the LTP measurement results. By this approach, we found that this has a constant error. Thus, the window glass air pressure error can be effectively removed from the measurement result to reveal the real mirror profile. Using the in situ LTP measuring result and the data iteration process, the bendable mirror can control the optical surface locate profile and thereby minimize the thermal distort effect. The slope error will be reduced to 0.1 μrad at the thermal load.
The project of transmission x-ray microscope (TXM) with tender x-ray is undergoing as an extension project of the soft x-ray tomography (SXT) endstation at Taiwan Photon Source (TPS). This TXM is aimed for energy from 1.5 keV to 2.4 keV and with phase contrast with the x-ray energy of 2.4 keV. As the extension of current SXT project, the beamline will be equipped with a variable line spacing (VLS) grating with the multi-layer coating which will be optimized for 2.4 keV.
This TXM will be zoneplate based with a phase ring and capillary condenser. In order to match the field of view and numerical aperture (NA) of zoneplate with the emittance of the source in vertical direction, some compromise should be made. To match the low emittance of vertical direction, the NA of zoneplate should be lower and vertical of the secondary source should be larger. This will lower spatial resolution and energy resolution. The targeting resolution of this TXM for phase contrast will be 50nm and FOV is 20 μm. For the detector, which is currently design with a scintillator with a CCD detector. For the future, the direct detector for small pixel and high signal to noise ratio can be obtained. The other components of TXM, such as stages, cryo system, which can be shared with current SXT system which works under the energy of the water window region.
This endstation for tender X-ray will be commission in 2020. The detailed design and current progress will be discussed in this presentation.
The PXM (Projection X-ray Microscope) end station was used to complete a preliminary test at the SPring-8 12B2 beamline. The x-ray through scintillator and knife-edge become visible-light image can get from the sensor. The knifeedge image has an edge shape, which can create the edge response line. The edge response line can be differentiated from the point response line. The point response line can then be transferred by Fourier transformation, and achieve MTF (Modulation Transfer Function). Here we apply Chebyshev polynomials to fit the edge response line and calculate the MTF. We used 20× and 50× objective lenses to generate the knife-edge images and calculate the MTF value. We found that the scintillator design resolution is 1 μm, and following the MTF calculation, the image resolutions are about 3 μm and 1.4 μm in the 20× and 50× objective lens, respectively.
To achieve an ultrahigh resolution for soft X-ray beamlines at Taiwan Photon Source (TPS), the slope error of a highly precise grating is required on level of 0.1 μrad (rms) under thermal loading with various curvatures. On the beamline, some optics are usually operating under high power density from undulator magnet, the thermal load will introduce a thermal bump on the optics profile and degrade the beamline performance, such as energy resolution and beam size.
To realize the high resolution goal, a specially designed bender with 25 actuators for the grating is designed and a In situ long trace profiler (LTP) with precision of 0.1 μrad (rms) has been developed to measure the mirror profile in soft X-ray beamlines.
This article introduces the design and construction of in situ LTP. It can provide a feedback guideance for the adjustment of actuators of bender mechanism to achieve the optium profile. A suitable adjustment procedure from the input of in-situ LTP , performance of bender and energy spectrums are presented.
There are several benders as the active mirrors and active gratings in operation in TPS 41A resonant inelastic X-ray scattering (RIXS) and TPS 45A angle-resolved photoemission spectroscopy (ARPES) beamlines. In the meantime, three in situ LTPs have been developed to monitor the grating profile under the thermal load in the beamlines. They are providing a feedback to measure the surface figure and to find the optimal surface profile. They would increase our efficiency to reach the energy resolving power of 35,000 and 28,000 in the RIXS and ARPES beamlines, respectively.
The project “High loading precision rotation stage design for synchrotron radiation mirror measurement” aims to provide an ultra-high-precision heavy-duty rotation stage and X-ray mirror interference optical measurements. Since the shape of an X-ray lens is very different from that of the general visible optical lens, the measurement system is very different from the general visible light optical measurement system. This paper describes a high-load precision rotating platform for obtaining stitching interferometer measurements for a synchrotron radiation mirror. The synchrotron radiation mirror is usually rectangular, and the length is greater than the interferometer measurement size. Therefore, for the mirror measurement, the stitching method is usually used to obtain synchrotron radiation mirror measurements. The interference measurements are obtained at different positions. In order to obtain the measurements, the center line of the interferometer must be perpendicular to the tangent of the mirror surface, so that appropriate interference fringes can be obtained. As the mirror radius becomes smaller, the interferometer rotation angle sensitivity increases. Development of the stitching interferometer high-load precision rotating platform design target requires an angle rotation resolution <10 nrad, considering the weight of the general interferometer plus the reference lens, related accessories, and safety factors is about 50 kg so that the rotating platform design load is 70 kg.
The thermal transfer issue is an important problem associated with the synchrotron radiation optical system. During projection x-ray microscopy (PXM), x-ray light comes from the wiggler insert parts. The vertical collimating mirror (VCM) absorbs 40 W of energy on the mirror surface. The mirror length is 1000 mm, and its width is 87 mm. Here we apply an x-ray optical simulation software, named SHADOW, as well as the finite element method (FEM) software, ANSYS®, to calculate the surface thermal deformation at various thicknesses of VCM. The FEM software calculates the mirror surface deformation from heat absorption, and the surface deformation can be fit by the B-spline curve. The thermal deformation fitting results can be fed back to the SHADOW software and be used to evaluate how mirror thermal deformation affects the optical system performance.
The diffraction-limited Montel mirrors, equipped at the X-ray Nanoprobe (XNP) at Taiwan Photon Source (TPS), provide a 40 nm focal spot and working distance 55 mm under the total beamline length of 69 m. The underneath holder supporting for the Montel mirrors is a 12 axes flexure based manipulators in which 10 out of the 12 axes are motorized. To monitor the position and stability of individual holder motion, a monitoring system consisted of three optical encoders and three- axes laser interferometers for angle movement is implemented. The gap width between the two mirrors and their orthogonality can be adjusted by a tilting sensor and a high magnification optical microscope. The focusing properties, phase and amplitude, after the Montel mirrors will be investigated by means of coherent Ptychography, as well as by zone plate imaging. An SEM in close cooperation with laser interferometers is equipped to precisely position the samples and conduct the on-the-fly scan. A high speed FPGA based circuit is developed to address signal from XRF, XAS, XEOL and XRD. Data is in tag with position and time information and been processed by computers to allow 5nm precision stage scanning free from mechanical feedback. The XNP at TPS is under commissioning since February 2017. The commissioning result, particularly the performance of the Montel mirrors will be reported in this presentation.
This on-the-fly scanning control system is for the x-ray nanoprobe endstation at Taiwan Photon Source(TPS) and built base-on the high speed Hardware (H/W), high throughput data stream and multi-channel control interfaces. The main idea is to tag each data with information of time and position, which generates by circuit and laser interferometer. The data is then processed by a computer to be analyzed and visualized.
By using high speed FPGA with embedded processer to process the input and output data which includes the DAC, ADC, Gigabit Ethernet (GbE), X-ray fluorescence (XRF) and laser interferometer control interfaces. Three DAC control the X,Y and Z axes of the flexure stage, four ADCs and sensor interfaces gather the data and packet it into data packet. GbE send data back to computer to do image processing then reconstruct the scanning image. The numerous data not only for rebuild the image but also good for information analysis. Including the vibration, time slide analysis.
Our demo system is built by an e-beam source, flexure stage and laser interferometer. The current maximum scanning speed is up to 5 lines/sec which is limited by the mechanical, the sample rate can be as high as 20M samples/sec which limited by laser interferometer, and the maximum data rate is close to 100M bytes/sec which is limited by the GbE. Interferometer information combine with position data in data packet, makes easy for data analysis and also for image stitching. The system is going to commission on beamline at March, 2017. The commission result for this system will be presented.
The hard X-ray nanoprobe at Taiwan Photon Source (TPS) makes use of the large numerical aperture obtained by nested Montel mirrors. To fully uptake the focusing power and flux, these mirrors requires the surface slope error no less than 0.05 μrad and are symmetrically placed with a 45 degrees cut for perfect surface matching. The beamline optics is designed to take the advantage of the symmetry of mirrors such that a round focal spot is accomplished. The final size of the focus spot are simulated below 40 nm at 9-15 keV. The whole facility including the beamline and the stations will be operated under vacuum to preserve photon coherence as well as to prevent the system from unnecessary environmental interference. The station equips with multimodal x-ray probes, including XRF, XAS, XEOL, projection microscope, CDI, etc. A SEM in close cooperation with laser interferometers is equipped to precisely locate the position of the sample. The beamline and the station are scheduled to be in commissioning phase in 2016.
Zone plate [1] has been used as a focal lens in transmission X-ray microscope (TXM) optical system in recent decades
[2, 3]. In TXM of NSRRC[4,5], the thickness of zone plate is about 900nm and the width of its out most zones is 50nm,
which has a high aspect ratio 18. When zone plate is tilted, the image quality will be affected by aberration. Since the
aspect ratio of zone plate is large, for incident beam, the shape of zone plate's transmission function will look different
when zone plate is tilted.
The both experimental and simulation result will be shown in this present. A five axes stage is designed and
manufactured for the zone plate holder for three dimensional movement, tip and tilt. According to Fourier theory, we can
calculate the wave distribution on image plane, if we know the original wave function, the distances between each
element, and the transparencies of the sample and zone plate. A parallel simulation process code in MATLAB is
developed in workstation cluster with up to 128Gbytes memory. The effects of aberration generated by tilt effect are
compared from the experimental data and simulation result. A maximum tilt angle within the acceptable image quality is
calculated by simulation and will be verified by experiment.
We have demonstrated dark-field imaging using a full-field hard x-ray microscope by using a custom capillary-based condenser. The condenser provides illumination with a numeric aperture about 3-mrad with high efficiency. This high illumination angle allows full-resolution imaging using a 50 nm hard x-ray zone plate. The zeroth order beam from the condenser is well out of the zoneplate range - which allows a high signal-to-noise ratio in the image plane. Small particles with high scattering power, such as colloidal gold markers used in biology are well-suited for dark-field imaging. Combining with high brightness source from NSRRC BL01B, the dark field image can be acquired within several minutes with high contrast ratio. In this paper, the dark field image of IC and the zoneplate defect will be demonstrated and studied in different energy under dark field mode.
Pulse readout technique is viewed as a way to improve the CNR ofreadout signal on super resolution disks, such as Magneto-optical Super Resolution Center Aperture Detection disk (MSR-CAD), Erasable Phase change Super Resolution disk (EPSR), Thermal distribution generated by pulse readout scheme results in more regular shape apertures and narrower wall width on those super resolution disks which leads to better signal quality.
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