γ-ray spectra detected with HgI2 at room temperature

Abstract

Detectors for γ rays working at room temperature were made of HgI₂ grown from the vapor phase by the method of dynamic gradient reversal. These detectors show a resolution (FWHM) of 2.3–3.5 keV for ²⁴¹Am γ rays (59.5 keV) with negligible effects on polarization and spectral response for counting rates up to 5000/sec. For ¹³⁷Cs γ rays (662 keV), the resolution could be increased for the first time to about 50 keV, provided that the thickness of the detectors was not more than about 0.5 mm. With a quasihemispherical detector, having a better efficiency, it was also possible to obtain a ¹³⁷Cs spectrum with a pronounced photopeak.