Characterization of the Uniformity of High-Flux CdZnTe Material

Since the late 2000s, the availability of high-quality cadmium zinc telluride (CdZnTe) has greatly increased. The excellent spectroscopic performance of this material has enabled the development of detectors with volumes exceeding 1 cm3 for use in the detection of nuclear materials. CdZnTe is also of great interest to the photon science community for applications in X-ray imaging cameras at synchrotron light sources and free electron lasers. Historically, spatial variations in the crystal properties and temporal instabilities under high-intensity irradiation has limited the use of CdZnTe detectors in these applications. Recently, Redlen Technologies have developed high-flux-capable CdZnTe material (HF-CdZnTe), which promises improved spatial and temporal stability. In this paper, the results of the characterization of 10 HF-CdZnTe detectors with dimensions of 20.35 mm × 20.45 mm × 2.00 mm are presented. Each sensor has 80 × 80 pixels on a 250-μm pitch and were flip-chip-bonded to the STFC HEXITEC ASIC. These devices show excellent spectroscopic performance at room temperature, with an average Full Width at Half Maximum (FWHM) of 0.83 keV measured at 59.54 keV. The effect of tellurium inclusions in these devices was found to be negligible; however, some detectors did show significant concentrations of scratches and dislocation walls. An investigation of the detector stability over 12 h of continuous operation showed negligible changes in performance.

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LPE grown LSO:Tb scintillator films for high-resolution X-ray imaging applications at synchrotron light sources

Nuclear Instruments and Methods in Physics Research Section A Accelerators Spectrometers Detectors and Associated Equipment ◽

10.1016/j.nima.2010.10.150 ◽

2011 ◽

Vol 648 ◽

pp. S321-S323 ◽

Cited By ~ 32

Author(s):

A. Cecilia ◽

A. Rack ◽

P.-A. Douissard ◽

T. Martin ◽

T. dos Santos Rolo ◽

...

Keyword(s):

High Resolution ◽

Light Sources ◽

X Ray ◽

X Ray Imaging ◽

Synchrotron Light ◽

Synchrotron Light Sources

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Development of an X-ray imaging system to prevent scintillator degradation for white synchrotron radiation

Journal of Synchrotron Radiation ◽

10.1107/s1600577518003193 ◽

2018 ◽

Vol 25 (3) ◽

pp. 801-807 ◽

Cited By ~ 8

Author(s):

Tunhe Zhou ◽

Hongchang Wang ◽

Thomas Connolley ◽

Steward Scott ◽

Nick Baker ◽

...

Keyword(s):

High Speed ◽

Imaging System ◽

Dust Particles ◽

Light Sources ◽

Contrast Imaging ◽

X Ray ◽

X Ray Imaging ◽

Synchrotron Light ◽

Cost Efficient ◽

Synchrotron Light Sources

The high flux of the white X-ray beams from third-generation synchrotron light sources can significantly benefit the development of high-speed X-ray imaging, but can also bring technical challenges to existing X-ray imaging systems. One prevalent problem is that the image quality deteriorates because of dust particles accumulating on the scintillator screen during exposure to intense X-ray radiation. Here, this problem has been solved by embedding the scintillator in a flowing inert-gas environment. It is also shown that the detector maintains the quality of the captured images even after days of X-ray exposure. This modification is cost-efficient and easy to implement. Representative examples of applications using the X-ray imaging system are also provided, including fast tomography and multimodal phase-contrast imaging for biomedical and geological samples.

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The emerging role of 4D synchrotron X-ray micro-tomography for climate and fossil energy studies: five experiments showing the present capabilities at beamline 8.3.2 at the Advanced Light Source

Journal of Synchrotron Radiation ◽

10.1107/s1600577517012449 ◽

2017 ◽

Vol 24 (6) ◽

pp. 1237-1249 ◽

Cited By ~ 3

Author(s):

Marco Voltolini ◽

Abdelmoula Haboub ◽

Shan Dou ◽

Tae-Hyuk Kwon ◽

Alastair A. MacDowell ◽

...

Keyword(s):

Uniaxial Stress ◽

Light Sources ◽

Micro Computed Tomography ◽

X Ray ◽

Deep Aquifers ◽

X Ray Imaging ◽

Oil Shale Pyrolysis ◽

Synchrotron Light ◽

Micro Tomography ◽

Synchrotron Light Sources

Continuous improvements at X-ray imaging beamlines at synchrotron light sources have made dynamic synchrotron X-ray micro-computed tomography (SXR-µCT) experiments more routinely available to users, with a rapid increase in demand given its tremendous potential in very diverse areas. In this work a survey of five different four-dimensional SXR-µCT experiments is presented, examining five different parameters linked to the evolution of the investigated system, and tackling problems in different areas in earth sciences. SXR-µCT is used to monitor the microstructural evolution of the investigated sample with the following variables: (i) high temperature, observingin situoil shale pyrolysis; (ii) low temperature, replicating the generation of permafrost; (iii) high pressure, to study the invasion of supercritical CO2in deep aquifers; (iv) uniaxial stress, to monitor the closure of a fracture filled with proppant, in shale; (v) reactive flow, to observe the evolution of the hydraulic properties in a porous rock subject to dissolution. For each of these examples, it is shown how dynamic SXR-µCT was able to provide new answers to questions related to climate and energy studies, highlighting the significant opportunities opened recently by the technique.

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Repeatability and sensitivity characterization of the far-field high-energy diffraction microscopy instrument at the Advanced Photon Source

Journal of Synchrotron Radiation ◽

10.1107/s1600577521008286 ◽

2021 ◽

Vol 28 (6) ◽

Author(s):

Jun-Sang Park ◽

Hemant Sharma ◽

Peter Kenesei

Keyword(s):

High Energy ◽

Light Sources ◽

Far Field ◽

Synchrotron Light ◽

Synchrotron Light Sources ◽

Non Destructive ◽

Diffraction Microscopy ◽

Photon Source ◽

Instrument Sensitivity

In the last two decades, far-field high-energy diffraction microscopy (FF-HEDM) and similar non-destructive techniques have been actively developed at synchrotron light sources around the world. As these techniques (and associated analysis tools) are becoming more available for the general users of these light sources, it is important and timely to characterize their performance and capabilities. In this work, the FF-HEDM instrument implemented at the 1-ID-E endstation of the Advanced Photon Source (APS) is summarized. The set of measurements conducted to characterize the instrument's repeatability and sensitivity to changes in grain orientation and position are also described. When an appropriate grain matching method is used, the FF-HEDM instrument's repeatability is approximately 5 µm in translation, 0.02° in rotation, and 2 × 10−4 in strain; the instrument sensitivity is approximately 5 µm in translation and 0.05° in rotation.

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Charge Sharing and Charge Loss in High-Flux Capable Pixelated CdZnTe Detectors

Sensors ◽

10.3390/s21093260 ◽

2021 ◽

Vol 21 (9) ◽

pp. 3260

Author(s):

Kjell A. L. Koch-Mehrin ◽

Sarah L. Bugby ◽

John E. Lees ◽

Matthew C. Veale ◽

Matthew D. Wilson

Keyword(s):

Carrier Transport ◽

Hole Transport ◽

Uniform Electric Field ◽

Photon Flux ◽

High Flux ◽

Charge Sharing ◽

Cdte Detector ◽

Charge Loss ◽

Cdznte Detectors ◽

Detector Model

Cadmium zinc telluride (CdZnTe) detectors are known to suffer from polarization effects under high photon flux due to poor hole transport in the crystal material. This has led to the development of a high-flux capable CdZnTe material (HF-CdZnTe). Detectors with the HF-CdZnTe material have shown promising results at mitigating the onset of the polarization phenomenon, likely linked to improved crystal quality and hole carrier transport. Better hole transport will have an impact on charge collection, particularly in pixelated detector designs and thick sensors (>1 mm). In this paper, the presence of charge sharing and the magnitude of charge loss were calculated for a 2 mm thick pixelated HF-CdZnTe detector with 250 μm pixel pitch and 25 μm pixel gaps, bonded to the STFC HEXITEC ASIC. Results are compared with a CdTe detector as a reference point and supported with simulations from a Monte-Carlo detector model. Charge sharing events showed minimal charge loss in the HF-CdZnTe, resulting in a spectral resolution of 1.63 ± 0.08 keV Full Width at Half Maximum (FWHM) for bipixel charge sharing events at 59.5 keV. Depth of interaction effects were shown to influence charge loss in shared events. The performance is discussed in relation to the improved hole transport of HF-CdZnTe and comparison with simulated results provided evidence of a uniform electric field.

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