X-ray micro-beam characterization of a small pixel spectroscopic CdTe detector

Veale, Matthew C.; Bell, S.; Seller, P.; Wilson, Matthew D.; Kachkanov, V.

doi:10.1088/1748-0221/7/07/p07017

Cited by 23 publications

(24 citation statements)

References 31 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…These finding suggests that not only are impurities in and around the inclusion resulting in charge trapping but also that its presence is leading to a local reduction in the electric field and, as a result, an increase in the proportion of charge sharing. These effects are consistent with previous results measured in CdZnTe and CdTe detectors [ 27 , 31 ].…”

Section: Resultssupporting

confidence: 93%

“…Similar features in CdZnTe material have been reported previously by Veale et al [ 27 ] in Redlen spectroscopic-grade CdZnTe and more recently by Tsigaridas et al [ 7 ] in Redlen HF-CdZnTe. Similar defects have also been studied in other material systems, such as CdTe [ 28 ] and GaAs [ 29 ], where they have been described as ‘dislocation walls’.…”

Section: Resultssupporting

confidence: 88%

See 1 more Smart Citation

Characterization of the Uniformity of High-Flux CdZnTe Material

Veale

Booker

Cross

et al. 2020

Sensors

View full text Add to dashboard Cite

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.

show abstract

Section: Resultssupporting

confidence: 93%

Section: Resultssupporting

confidence: 88%

Characterization of the Uniformity of High-Flux CdZnTe Material

Veale

Booker

Cross

et al. 2020

Sensors

View full text Add to dashboard Cite

show abstract

“…The detector array has a pixel pitch of 250 µm, a inter pixel spacing of 50 µm and an energy resolution of 0.8 keV at 59.5 keV [Veale et al, 2012]. Each pixel has an identical integrated circuit consisting of amplifiers and charge shapers.…”

Section: Methodsmentioning

confidence: 99%

Scatter free imaging for the improvement of breast cancer detection in mammography

et al. 2016

Self Cite

View full text Add to dashboard Cite

Abstract. In mammography, the reduction of scattered X-rays is vital due to the low contrast or small dimension of the details that are searched for. The typical method of doing so in current conventional mammography is the anti-scatter grid. The disadvantage of this method is the absorption of a proportion of the primary beam and therefore an increase in dose is required to compensate for the loss of counts. An alternative method is proposed, using quasi-monochromatic beams and a pixellated spectroscopic detector. As Compton-scattered X-rays lose energy in the scattering process, they are detected at a lower energy in the spectrum. Therefore the spectrum can be windowed around the monochromatic energy peak, removing the scattered Xrays from the image. The work presented here shows contrast improvement of up to 50 % and contrast to noise ratio improvements of around 20 % for scatter free imaging in comparison to full spectrum imaging. Contrast improvements of around 45 % were found when comparing scatter free images to conventional polychromatic imaging for both the low contrast test object and the Rachel anthropomorphic breast phantom.

show abstract

“…The sensor is a 2 cm x 2 cm x 0.1 cm CdTe wafer; the readout array has a 250 µm pixel pitch with 50 µm interpixel spacing and an energy resolution of 0.8 keV at 59.5 keV 8 . Each channel has an identical set of electronics associated with it consisting of amplifiers, charge shapers and a peak hold circuit that measures the magnitude of the pulse produced by each photon when it interacts with the CdTe material, which can then be converted to energy by linear calibration 9 .…”

Section: Hexitec Pixellated Spectroscopic Detectormentioning

confidence: 99%

Scatter-free breast imaging using a monochromator coupled to a pixellated spectroscopic detector

et al. 2015

View full text Add to dashboard Cite

This project uses the combination of a spectroscopic detector and a monochromator to produce scatter free images for use in mammography. Reducing scatter is vital in mammography, where typical structures have either low contrast or small dimensions. The typical method to reduce scatter is the anti-scatter grid, which has the drawback of absorbing a fraction of the primary beam as well as scattered radiation. An increase in the dose is then required in order to compensate. Compton-scattered X-rays have lower energy than the primary beam. When using a monochromatic beam and a spectroscopic detector the scattered beam will appear at lower energies than the primary beam in the detected spectrum. Therefore if the spectrum of the detected X-rays is available, the scattered component can be windowed out of the spectrum, essentially producing a scatter free image. The monochromator used in this study is made from a Highly Orientated Pyrolytic Graphite (HOPG) crystal with a mosaic spread of 0.4°±0.1°. The detector is a pixellated spectroscopic detector that is made from a 2 cm x 2 cm x 0.1 cm CdTe crystal with a pixel pitch of 250 µm and an energy resolution of 0.8 keV at 59.5 keV. This work presents the characterisation of the monochromator and initial imaging data. The work shows a contrast increase of 20% with the removal of the low energy Compton scattered X-rays.

show abstract

X-ray micro-beam characterization of a small pixel spectroscopic CdTe detector

Cited by 23 publications

References 31 publications

Characterization of the Uniformity of High-Flux CdZnTe Material

Characterization of the Uniformity of High-Flux CdZnTe Material

Scatter free imaging for the improvement of breast cancer detection in mammography

Scatter-free breast imaging using a monochromator coupled to a pixellated spectroscopic detector

Contact Info

Product

Resources

About