X-Ray Silicon Drift Detector-CMOS Front-End System with High Energy Resolution at Room Temperature

TL;DR

This paper introduces a high-resolution X-ray detection system combining a Silicon Drift Detector with a CMOS preamplifier, achieving excellent energy resolution at room temperature for spectroscopic applications.

Contribution

The work presents a novel integration of a Silicon Drift Detector with a custom CMOS preamplifier, optimized for low noise and high energy resolution at room temperature.

Findings

Achieved energy resolution of 29 eV FWHM at 30°C

Reduced noise threshold to 165 eV

Demonstrated stable operation with low noise at room temperature

Abstract

We present a spectroscopic system constituted by a Silicon Drift Detector (SDD) coupled to a CMOS charge sensitive preamplifier, named SIRIO, specifically designed to reach ultimate low noise levels. The SDD, with an active area of 13 mm , has been manufactured by optimizing the production processes in order to reduce the anode current, successfully reaching current densities between 17 pA/cm and 25 pA/cm at 20 for drift fields ranging from 100 V/cm to 500 V/cm. The preamplifier shows minimum intrinsic noise levels of 1.27 and 1.0 electrons r.m.s. at 20 and 30 , respectively. At room temperature ( ) the 5.9 keV and the pulser lines have 136 eV and 64 eV FWHM, respectively, corresponding to an equivalent noise charge of 7.4 electrons r.m.s.; the noise threshold is at 165 eV. The energy resolution, as measured on the pulser line, ranges from 82 eV FWHM (9.4 electrons r.m.s.) at 30C down to 29 eV FWHM (3.3 electrons r.m.s.) at 30C .