Absolute calibration of X-ray semiconductor detectors against synchrotron radiation of the VEPP-3 storage ring

The results are presented of absolute spectral responsivity measurements for SPPD11 and SPPD11-04 pulse-type silicon semiconductor detectors (developed by the Research Institute of Pulse Technique, Moscow), carried out over the X-ray energy range from 1.5 keV to 20 keV with a relative uncertainty ( k = 1) of typically 5 × 10 −2 . In our measurements, the detector is positioned in a calculable synchrotron radiation flux behind filters of well-known transmittance. The spectral responsivity of the detector is restored on the basis of measurement data using a set of integral equations. Two procedures have been developed to improve the calibration accuracy: one for the experimental determination of the X-ray transmittance near the K absorption edge of the filters used, with a relative uncertainty not exceeding 2 × 10 −2 ; and another for the estimation of the angular spread of the electrons.