A versatile solid-state-detector spectrometer

The Low Energy X-Ray and Electron Spectrometer (LEXES) has been designed for the simultaneous measurement of photons and electrons with windowless solid-state detectors. Within this spectrometer two detectors can be moved independently of each other with respect to the source plane. LEXES has been used for the measurement of various parameters, and recently for the determination of conversion-electron ratios in the decay of sup(93m)Nb. As a further example of such measurements the redetermination of the relative K-capture probability Psub(K) in the decay of 139Ce is described. A value of Psub(K) = 0.75 +- 0.05 has been found which is in good agreement with recent measurements. (author)