Time and Energy Measurement Electronics for Silicon Drift Detector Aimed for X-ray Pulsar Navigation

TL;DR

This paper presents a high-resolution time and energy measurement electronic system for Silicon Drift Detectors, optimized for X-ray pulsar navigation, achieving nanosecond timing precision and sub-160 eV energy resolution.

Contribution

It introduces a novel FPGA-based readout electronics with integrated TDC and ADC for SDDs, tailored for X-ray pulsar navigation applications.

Findings

Time resolution of about 3 ns achieved

Energy spectrum FWHM better than 160 eV at 5.9 keV

Energy linearity residual less than 1.5%

Abstract

A readout electronic with high time and energy resolution performance is designed for the SDD (Silicon Drift Detector) signals readout, which is aimed for X-ray pulsar based navigation (XNAV). For time measurement, the input signal is fed into a fast shaping and Constant Fraction Discrimination (CFD) circuit, and then be digitalized by a Time-to-Digital Converter (TDC) implemented in an Field Programmable Gate Array (FPGA), which is designed with a bin size of 2.5 ns. For energy measurement, a slow shaping and analog peak detection circuit is employed to acquire the energy information of input signals, which is then digitalized by a 14-bit Analog-to-Digital Converter (ADC). Both the time and energy measurement results are buffered and packaged in FPGA and then transmitted to Data Processing (DP) system. Test results indicate that the time resolution is about 3 ns, while the FWHM (Full Width at Half Maximum) of energy spectrum is better than 160 eV @ 5.9 keV, with the energy dynamic range from 1 keV to 10 keV. Meanwhile, the linearity test shows that the residual is less than 1.5% with different coming photons.