Readout electronics for a high-resolution soft X-ray spectrometer based on silicon drift detector

Abstract

The readout electronics for a prototype soft X-ray spectrometer based on silicon drift detector (SDD), for precisely measuring the energy and arrival time of X-ray photons is presented in this paper. The system mainly consists of two parts, i.e., an analog electronics section (including a pre-amplifier, a signal shaper and filter, a constant fraction timing circuit, and a peak hold circuit) and a digital electronics section (including an ADC and a TDC). Test results with X-ray sources show that an energy dynamic range of 1–10 keV with an integral nonlinearity of less than 0.1% can be achieved, and the energy resolution is better than 160 eV @ 5.9 keV FWHM. Using a waveform generator, test results also indicate that time resolution of the electronics system is about 3.7 ns, which is much less than the transit time spread of SDD (<100 ns) and satisfies the requirements of future applications.