Absolute measurement of the Fano factor using a Skipper-CCD

Understand

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 $^{55}$Fe X-rays, getting a Fano factor absolute measurement in Si at 123K and 5.9 keV.
• A value of 0.119 $\pm$ 0.002 was found and the electron-hole pair creation energy was determined to be (3.749 $\pm$ 0.001) eV.