Investigations of Charge Collection and Signal Timing in a multi-pixel Silicon Drift Detector

TL;DR

This paper characterizes a multi-pixel silicon drift detector prototype for sterile neutrino detection, analyzing charge collection and signal timing to improve detector response understanding for dark matter searches.

Contribution

It provides experimental characterization and simulation comparison of a novel multi-pixel silicon drift detector for neutrino research.

Findings

Good agreement between experimental data and simulations.

Charge collection and timing depend on detector geometry.

High-resolution laser scans reveal detailed detector response.

Abstract

Sterile neutrinos are a minimal extension of the Standard Model of particle physics and a promising candidate for dark matter if their mass is in the keV-range. The Karlsruhe Tritium Neutrino experiment (KATRIN), equipped with a novel multi-pixel silicon drift detector array, the TRISTAN detector, will be capable of searching for these keV-scale sterile neutrinos by investigating the kinematics of the tritium $\beta$-decay. This measurement will be performed after the completion of the neutrino mass measurement campaign. To detect a sterile neutrino signal with a high sensitivity, a profound understanding of the detector response is required. In this work, we report on the characterization of a 7-pixel TRISTAN prototype detector with a laser system. We present the experimental results obtained in high-resolution scans of the detector surface with a focused laser beam and demonstrate how the charge collection and the timing of the signals generated in the detector is related to the detector geometry. A comparison of the experimental data with simulations shows a good agreement.