The Linearity of the Charge Conversion Function for Cooied Lithium-Drifted Silicon Detectors in Response to X-Ray and Low Energy Gamma Ray Excitation

The linearity of the collected charge/keV has been determined as a function of energy between 4.9 and 75 keV for cooled lithium-drifted silicon detectors. Nonlinear effects for applied field intensities up to 1 kV/cm have been observed to extend to photon energies above 30 keV. Extrapolation to infinite fields does not remove the nonlinear effects for photon energies below 10 keV, indicating an intrinsic nonlinear response at low energies. The charge conversion factor appears to be independent of energy within 0.2% down to 10 keV.