X-ray spectroscopy up to 17.6 keV using a Commercial Off The Shelf CMOS Image Sensor

It has been demonstrated that Commercial Off The Shelf CMOS Image Sensors (CIS) can be used to perform soft X-ray spectroscopy. In a previous work, we prove that it is possible to employ a CIS to perform soft X-ray spectroscopy in an energy range of 1 to 10 keV. In this work, we will demonstrate that by decreasing the gain of the CIS it is possible to extend the energy range of the method. We measured the fluorescence lines of Cu with different gains, and we also prove that it is possible to resolve the $\mathrm{k}\alpha$ and the $\mathrm{k}\beta$ lines of 15.77 and 17.66 keV of Zr. Analyzing the obtained spectra we observe that the response of the sensor is linear in the range of energies from 8 to 17.66 keV. Finally, we estimate the energy resolution and the conversion gain of the CIS in the employed configuration.