Silver Bromide Crystal Counters

Single crystals of silver bromide and mixed crystals of sodium and silver chloride have been used to count ionizing radiation. The energy per ion pair in silver bromide for electrons was found to be approximately 5.8 ev. The mobility and the mean free path for the trapping of electrons in the conduction band of silver bromide crystals at 77°K were found to be 210 ${\mathrm{cm}}^2$/volt-sec and 5×${10}^{-4\mathrm{}}$ ${\mathrm{cm}}^2$/volt, respectively. A study of the polarization of the counters for beta- and gamma-radiation was also made.