Pair creation energy and Fano factor of silicon measured at 185 K using 55Fe X-rays

The pair creation energy, ω and the Fano factor of silicon were measured using a CCD sensor and X-rays from an 55Fe source. The measurements were performed at a sensor temperature of 185K. The pair creation energy was measured for X-rays in the 1.7-6.5 keV range. The measured pair creation energy is ω=(3.650±0.009)eV at the MnKα line energy. The Fano factor at this energy is F=0.128±0.001. The agreement with theory and previous measurements is satisfactory. The system gain was obtained from flat field exposures using the Poisson distribution properties. These results and the details of our measurement procedure are presented below.