Charge collection efficiency characterization of a HgI2 Frisch collar spectrometer with collimated high energy gamma rays

In this study, a 2.1×2.1×4.1 mm³ HgI₂ Frisch collar device was characterized through probing the device with a highly collimated 662 keV gamma rays (¹³⁷Cs check source) along the length and width of the device. In a systematic series of experiments, the detector was probed along its central line under different operating voltages of 1600, 1300, 1000, 800, 600 and 500 V. The experimental results were confirmed through a simulation of the charge collection for a device with the same size and operating conditions. It is shown that the HgI₂ Frisch collar device has a uniform response to gamma rays over two-thirds of the detector volume. The HgI₂ crystals and the Frisch collar detectors were grown and fabricated within the S.M.A.R.T Laboratory at Kansas State University.