Silicon drift detectors with enlarged sensitive areas

Abstract

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.

Design of optimum filters for signal processing with silicon drift detectors

“…X-ray absorptions near the anode lead to short drift times and fast signals, while X-ray absorptions near the edges lead to long drift times and slow signals. 14,15 For small detectors (e.g., 20 mm 2 active area) with a fast-readout ASIC signal rise-times typically vary between 20 ns and 80 ns and for large detectors (e.g., 80 mm 2 active area) signal rise-time are typically in the range between 20 ns and 250 ns. The obtained reference signal has a signal rise-time corresponding to the average signal rise-time of the detector.…”

“…For silicon drift detectors, signal rise‐times vary due to the different drift times of electrons in the semiconductor material. X‐ray absorptions near the anode lead to short drift times and fast signals, while X‐ray absorptions near the edges lead to long drift times and slow signals 14,15 . For small detectors (e.g., 20 mm 2 active area) with a fast‐readout ASIC signal rise‐times typically vary between 20 ns and 80 ns and for large detectors (e.g., 80 mm 2 active area) signal rise‐time are typically in the range between 20 ns and 250 ns.…”

Atomic spectrometry update. X-Ray fluorescence spectrometry

“…As a result of this careful study, the authors were able to suggest methods to correct some of the peak shift. Eggert and colleagues 34 described the sources of noise in SDDs and how the performance of SDDs degrades with increasing active area as a result of increased leakage and of charge cloud diffusion during its drift. The constraints for simple scaling of a single device were described in detail and geometric configurations for larger area multichannel SDDs were proposed, including a 12-channel SDD, although the inevitable complexity, cost and limitations of needing 12 readout channels did not go without comment.…”

The spectral response of silicon X-ray detectors

“…Silicon drift detectors (SDDs) become more and more competitive to high-end Si(Li) detectors in energy dispersive X-ray spectroscopy [1][2][3][4][5]. They feature energy resolutionso140 eV at 5.9 keV and shaping times of only 1 ms, active areas of up to 100 mm 2 and high count-rate capabilities (10 5 =s210 6 =s).…”