Radiation damage measurements in room temperature semiconductor radiation detectors

摘要

The literature of radiation damage measurements on cadmium zinc telluride (CZT), cadmium telluride (CT), and mercuric iodide (HgI2) is reviewed and in the case of CZT supplemented by new alpha particle data. CZT strip detectors exposed to intermediate energy (1.3 MeV) proton fluences exhibit increased interstrip leakage after 10 to the 10th power p/sq cm and significant bulk leakage after 10 to the 12 power p/sq cm. CZT exposed to 200 MeV protons shows a two-fold loss in energy resolution after a fluence of 5 x 10 to the 9th power p/sq cm in thick (3 mm) planar devices but little effect in 2 mm devices. No energy resolution effects were noted from moderated fission spectrum of neutrons after fluences up to 10 to the 10th power n/sq cm, although activation was evident. Exposures of CZT to 5 MeV alpha particle at fluences up to 1.5 x 10 to the 10th power alpha/sq cm produced a near linear decrease in peak position with fluence and increases in FWHM beginning at about 7.5 x 10 to the 9th power alpha /sq cm. CT detectors show resolution losses after fluences of 3 x 10 to the 9th power p/sq cm at 33 MeV for chlorine-doped detectors. Indium doped material may be more resistant. Neutron exposures (8 MeV) caused resolution losses after fluences of 2 x 10 to the 10th power n/sq cm. Mercuric iodide has been studied with intermediate energy protons (10 to 33 MeV) at fluences up to 10 to the 12th power p/sq cm and with 1.5 GeV protons at fluences up to 1.2 x 10 to the 8th power p/sq cm. Neutron exposures at 8 MeV have been reported at fluences up to 10 to the 15th power n/sq cm. No radiation damage was reported under these irradiation conditions.