Absolute measurement of the Fano factor using a Skipper-CCD
Abstract
Skipper-CCD can achieve deep sub-electron readout noise making possible the absolute determination of the exact number of ionized electrons in a large range, from 0 to above 1900 electrons. In this work we present a novel technique that exploits this unique capability to allow self-calibration and the ultimate determination of silicon properties. We performed an absolute measurement of the variance and the mean number of the charge distribution produced by 55Fe X-rays, getting a Fano factor absolute measurement in Si at 123K and 5.9 keV. A value of 0.119 0.002 was found and the electron-hole pair creation energy was determined to be (3.749 0.001) eV. This technology opens the opportunity for direct measurements of the Fano factor at low energies.