Linearity discontinuities in Xe-filled X-ray microstrip detectors

A prototype Xe ÷ 10% CH4 microstrip detector was used to study the K-edge discontinuity in the pulse-height distribution as a function of the energy of incident X-rays. The electronics used was such that a pulse-shape rejection could be made of K-fluorescence reabsorption in the detector. The measured jump at the K-edge was (169 ± 12) eV. It was also seen that Kα- and Kβ-decay channels produce different pulse heights for the same deposited energy. We find that the difference in energy between the calibration lines of the Kβ2- and the Kβ1.3-escape peaks is (93 ± 12) eV whereas between the Kβ1.3 and the Kα-escape peaksʹ calibration the energy gap is (69 ± 7) eV.