A gaseous-helium cooling system for silicon detectors in the Nab experiment

TL;DR

This paper presents a gaseous helium cooling system designed to maintain silicon detectors at below 150 K with high stability, crucial for the Nab experiment's precise measurements of neutron beta decay.

Contribution

It introduces a novel gaseous helium cooling system specifically developed for silicon detectors in the Nab experiment, ensuring stable low-temperature operation.

Findings

Cooling system achieves below 150 K temperature

Maintains temperature stability within +/- 0.5 K

Supports precise neutron decay measurements

Abstract

The Nab experiment aims to extract the neutron beta decay correlation coefficients 'a' and 'b'. This will be accomplished using a 7 m tall electromagnetic spectrometer which measures electron energies and proton momenta. Detection of electrons and protons resulting from neutron beta decay will be carried out using large-area, thick, highly-segmented, single-crystal silicon detectors. These detectors and accompanying electronics will be cooled by a recirculating, gaseous helium cooling system to below 150 K with +/- 0.5 K stability. We will motivate the need for detector cooling in the Nab experiment and discuss design and performance of this cooling system.