Silicon drift detectors with enlarged sensitive areas

The silicon drift detector is a compact, high-resolution and energy-dispersive x-ray detector. The differences between the conventional silicon drift detectors with an active area of 5 mm(2) and new detectors with larger areas are outlined. Several constraints from fundamental physical and electronic properties are given, which limit the achievable energy resolution and size of the active area. The expected characteristics of larger upcoming devices are calculated. The deterioration of the energy resolution at very high count rates is quantitatively explained. Some limitations are eliminated if the chip is segmented into several cells with individual read-out nodes. Copyright (C) 2004 John Wiley Sons, Ltd.