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Energy response characterization of InGaP X-ray detectors
Version 2 2023-06-12, 07:29
Version 1 2023-06-09, 15:47
journal contribution
posted on 2023-06-12, 07:29 authored by Grammatiki LioliouGrammatiki Lioliou, A B Krysa, Anna BarnettAnna BarnettTwo custom-made In0.5Ga0.5P p+-i-n+ circular mesa spectroscopic X-ray photodiodes with different diameters (200 µm and 400 µm) and a 5 µm i layer have been characterized for their response to X-ray photons within the energy range 4.95 keV to 21.17 keV. The photodiodes, operating uncooled at 30 °C, were coupled, in turn, to the same custom-made charge-sensitive preamplifier. X-ray fluorescence spectra of high-purity calibration foils excited by a Mo target X-ray tube were accumulated. The energy resolution (Full Width at Half Maximum) increased from 0.79 keV ± 0.02 keV at 4.95 keV to 0.83 keV ± 0.02 keV at 21.17 keV, and from 1.12 keV ± 0.02 keV at 4.95 keV to 1.15 keV ± 0.02 keV at 21.17 keV, when using the 200 µm and 400 µm diameter devices, respectively. Energy resolution broadening with increasing energy was attributed to increasing Fano noise (negligible incomplete charge collection noise was suggested); for the first time the Fano factor for In0.5Ga0.5P was experimentally determined to be 0.13, suggesting a Fano limited energy resolution of 145 eV at 5.9 keV. The charge output of each system had a linear relationship with photon energy, across the investigated energy range. The count rate of both spectroscopic systems increased linearly with varying X-ray tube current up to ~105 photons s-1 cm-2 incident photon fluences. The development of In0.5Ga0.5P based spectrometers is particularly important for hard X-/?-ray astronomy, due to the material’s large linear X-ray and ?-ray absorption coefficients and ability to operate uncooled at high temperatures.
Funding
Radioisotope Microbatteries; G1951; STFC-SCIENCE AND TECHNOLOGY FACILITIES COUNCIL; ST/P001815/1
History
Publication status
- Published
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- Published version
Journal
Journal of Applied PhysicsISSN
0021-8979Publisher
AIP PublishingExternal DOI
Volume
124Article number
a195704Department affiliated with
- Engineering and Design Publications
Research groups affiliated with
- Space Research Group Publications
Notes
A.M.B. acknowledges funding from the Leverhulme Trust, United Kingdom, in the form of a 2016 Philip Leverhulme Prize.Full text available
- Yes
Peer reviewed?
- Yes
Legacy Posted Date
2018-11-08First Open Access (FOA) Date
2018-11-08First Compliant Deposit (FCD) Date
2018-11-07Usage metrics
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