High-energy gamma spectra detected with imporved HgI2 spectrometers at room temperature

Abstract
The detection of the photopeak of the 662‐keV γ ray of 137Cs with a full width at half‐maximum (FWHM) of only 6.5 keV by a 0.5‐mm‐thick improved stoichiometry HgI2 crystal is reported. The 1173‐ and 1332‐keV γ photopeaks of 60Co have also been resolved for the first time. Polarization effects were negligible.