Progress in multi-element silicon detectors for synchrotron XRF applications

Multi-element silicon strip detectors, in conjunction with integrated circuit pulse-processing electronics, offer an attractive alternative to conventional lithium-drifted silicon and high purity germanium detectors for high count rate, low noise synchrotron X-ray fluorescence applications. We have been developing these types of detectors specifically for low noise synchrotron applications, such as extended X-ray absorption fine structure spectroscopy, microprobe X-ray fluorescence and total reflection X-ray fluorescence. The current version of the 192-element detector and integrated circuit preamplifier, cooled to -25°C with a single-stage thermoelectric cooler, achieves an energy resolution of <200 eV full width of half maximum (FWHM) per channel (at 5.9 keV, 2 μs peaking time), and each detector element is designed to handle ~20 kHz count rate. The detector system will soon be completed to 64 channels using new application specific integrated circuit amplifier chips, new CAMAC analog-to-digital converters recently developed at Lawrence Berkeley National Laboratory, CAMAC histogramming modules, and Macintosh-based data acquisition software. We report on the characteristics of this detector system, and the work in progress towards the next generation system