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Quantum efficiency measurements in the swept charge device CCD236

Smith, P. H.; Gow, J. P. D.; Murray, N. J.; Tutt, J. H.; Soman, Matthew and Holland, A. D. (2014). Quantum efficiency measurements in the swept charge device CCD236. Journal of Instrumentation, 9(4), article no. P04019.

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The e2v technologies plc. CCD236 is a Swept Charge Device (SCD) designed as a large area (20 mm × 20 mm) soft X-ray detector for spectroscopy in the range 0.8 keV to 10 keV. It benefits from improvements in design over the previous generation, the e2v CCD54, such as: a 4 times increased detector area, a reduction in split X-ray events due to the 100 μm × 100 μm `pixel' size, and improvements to radiation hardness. The CCD236 will be used in India's Chandrayaan-2 Large Soft X-ray Spectrometer (CLASS) instrument and China's Hard X-ray Modulation Telescope (HXMT).

Measurements of the Quantum Efficiency (QE) have been obtained relative to a NIST calibrated photodiode over the energy range 0.2 keV to 1.9 keV, using the BESSY II X-ray synchrotron in Berlin. Two X-ray event counting methods are described and compared, and QE for soft X-ray interaction is reported. Uniformity of QE across the device is also investigated at energies between 0.52 keV and 1.5 keV in different areas of the detector. This work will enable the actual number of photons incident on the detectors to be calculated, thus ensuring that the CCD236 detectors provide valuable scientific data during use. By comparing the QE methods in this paper with the event processing techniques to be used with CLASS, an estimate of the instrument-specific QE for CLASS can be provided.

Item Type: Journal Item
Copyright Holders: 2014 IOP Publishing Ltd and Sissa Medialab srl
ISSN: 1748-0221
Extra Information: 15 pp.
Keywords: X-ray detectors; spectrometers; X-ray detectors and telescopes; X-ray fluorescence (XRF) systems
Academic Unit/School: Faculty of Science, Technology, Engineering and Mathematics (STEM) > Physical Sciences
Faculty of Science, Technology, Engineering and Mathematics (STEM)
Research Group: Centre for Electronic Imaging (CEI)
Item ID: 40635
Depositing User: Users 9828 not found.
Date Deposited: 28 Jul 2014 10:38
Last Modified: 07 Dec 2018 10:24
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