Capabilities of Mercuric Iodide as a Room Temperature X-Ray Detector

Measurement results obtained with HgI2 detectors at room temperature in the low energy x-ray region down to 2 keV are reported. The best resolution obtained is 548 e V for 5.9 keV x-rays, and the 2.01 keV phosphorous x-ray line has been resolved with a detector with an area of 14 mm2. The different noise sources of the detector-amplifier system are analysed and polarization effects in the detectors are discussed. The mercuric iodide crystals were grown from the vapour phase by gradient reversal techniques.