Linearity and Resolution of Semiconductor Radiation Detectors

The energy linearity for Si(Li) and Ge(Li) has been measured and compared with theory. Good agreement was obtained for x-ray attenuation factors ¿md < 100 . The region of the germanium absorption edge was investigated and found to exhibit larger nonlinearities than predicted by the theory. The discrepancy is believed to be due to inefficient charge collection near the detector window leading to excessive fluctuations in the trapped charge. Calculations of the line broadening due to trapping have been shown to agree qualitatively with experimental values for the silicon detector. These calculations do not take into account any position dependent variation of the trapping factor, and must therefore be considered as the best attainable values. The disagreement between theory and experiment for the line broadening in Ge(Li) is particularly evident. The ¿ seems to be independent of energy in Si to less than 0.2% and in Ge to within at least 2% . Finally, the Fano factor in Si was found to be 0.154 +0.1 -0.2.