Radiation damage measurements in room-temperature semiconductor radiation detectors

The literature of radiation damage measurements on cadmium zinc telluride (CZT), cadmium telluride (CT), and mercuric iodide is reviewed and supplemented in the case of CZT by new alpha particle data. CZT strip detectors exposed to intermediate energy proton fluences exhibit increased interstrip leakage after 1010 p/cm2 and significant bulk leakage after 1012 p/cm2. CZT exposed to 200 MeV protons shows a two-fold loss in energy resolution after a fluence of 5 X 109 p/cm2 in thick planar devices but little effect in 2 mm devices. No energy resolution effects were noted from moderated fission spectrum neutrons after fluences up to 1010 n/cm2, although activation was evident. Exposures of CZT to 5 MeV alpha particle at fluences up to 1.5 X 1010 (alpha) /cm2 produced a near linear decrease in peak position with fluence and increases in FWHM beginning at about 7.5 X 109 (alpha) /cm2.