NEW FINDINGS OF X-RAY-ENERGY RESPONSES OF SILICON SURFACE-BARRIER DETECTORS AND THEIR GENERALIZED THEORETICAL EXTENSION TO X-RAY RESPONSES OF POSITION-SENSITIVE DETECTORS

X-ray energy responses of silicon surface barrier (SSB) semiconductor detectors are found to be explained neither by the commonly believed c onventional model using the depletion layer thickness of an SSB detect or nor by a recently proposed model using its wafer thickness as the X -ray sensitive layer. Our new theory using both the depletion layer se nsitivity and the X-ray response due to a three-dimensional charge dif fusion effect in the field-free substrate region of a SSB detector can well fit the response data. This theory is newly extended to analyze each channel response of a multichannel semiconductor X-ray detector f abricated on one silicon wafer; these detectors are widely utilized as position sensitive X-ray detectors for nuclear fusion oriented plasma research as well as for high energy elementary particle studies. A nu merical simulation of multichannel detector outputs using our three-di mensional diffusion theory is carried out; generalized theoretical for mulae are also presented.