Infrared LED Enhanced Spectroscopic CdZnTe Detector Working under High Fluxes of X-rays.
This paper describes an application of infrared light-induced de-polarization applied on a polarized CdZnTe detector working under high radiation fluxes. We newly demonstrate the influence of a high flux of X-rays and simultaneous 1200-nm LED illumination on the spectroscopic properties of a CdZnTe detector. CdZnTe detectors operating under high radiation fluxes usually suffer from the polarization effect, which occurs due to a screening of the internal electric field by a positive space charge caused by photogenerated holes trapped at a deep level. Polarization results in the degradation of detector charge collection efficiency. We studied the spectroscopic behavior of CdZnTe under various X-ray fluxes ranging between 5 × 10 5 and 8 × 10 6 photons per mm 2 per second. It was observed that polarization occurs at an X-ray flux higher than 3 × 10 6 mm - 2 ·s - 1 . Using simultaneous illumination of the detector by a de-polarizing LED at 1200 nm, it was possible to recover X-ray spectra originally deformed by the polarization effect.
Institute of Physics, Faculty of Mathematics and Physics, Charles University, Ke Karlovu 5, Prague 12116, Czech Republic. jakub.pekarek@karlov.mff.cuni.cz.
Jakub
J
Pekárek
Institute of Physics, Faculty of Mathematics and Physics, Charles University, Ke Karlovu 5, Prague 12116, Czech Republic. vaclav.dedic@mff.cuni.cz.
Václav
V
Dědič
Institute of Physics, Faculty of Mathematics and Physics, Charles University, Ke Karlovu 5, Prague 12116, Czech Republic. jan.franc@mff.cuni.cz.
Jan
J
Franc
Institute of Physics, Faculty of Mathematics and Physics, Charles University, Ke Karlovu 5, Prague 12116, Czech Republic. eduard.belas@mff.cuni.cz.
Eduard
E
Belas
Institute of Physics, Faculty of Mathematics and Physics, Charles University, Ke Karlovu 5, Prague 12116, Czech Republic. rejhonm@karlov.mff.cuni.cz.
Martin
M
Rejhon
Institute of Physics, Faculty of Mathematics and Physics, Charles University, Ke Karlovu 5, Prague 12116, Czech Republic. pavel.moravec@mff.cuni.cz.
Pavel
P
Moravec
Crytur Ltd., Palackého 175, Turnov 51101, Czech Republic. tous@crytur.cz.
Jan
J
Touš
National Radiation Protection Institute, Bartoškova 28, Prague 14000, Czech Republic. josef.voltr@suro.cz.
Josef
J
Voltr
CdZnTe; Pockels effect; X-ray detector; de-polarization; high flux; polarization
Sensors (Basel). 2009;9(5):3491-526
22412323
Sensors (Basel). 2013 Jul 22;13(7):9414-34
23881140