Measurement of the Ionization Yield of Neutron-Induced Proton Recoils in Tetramethylsilane

TL;DR

This study measures the ionization yield of neutron-induced proton recoils in Tetramethylsilane TPCs, demonstrating their potential for detecting MeV-scale neutrons with room temperature organic detectors.

Contribution

It provides the first detailed measurement of ionization yield dependence on electric fields in Tetramethylsilane for neutron detection.

Findings

Ionization yield depends on electric field as described by the Thomas-Imel model.

A quenching factor for proton recoils in Tetramethylsilane is established.

Room temperature organic detectors can effectively detect MeV-scale neutrons.

Abstract

We report on a low energy measurement of the ionization yield in a Tetramethylsilane Time Projection Chamber (TPC) using 2.8 MeV neutrons from a deuterium-deuterium neutron generator. The proton recoil charge yield is measured at four different electric fields, finding a dependence that is well described by the Thomas-Imel model. By comparing the proton recoil yield to that obtained from $\gamma$-ray calibrations, a quenching factor is obtained for each electric field. These results demonstrate the feasibility of using room temperature organic ionisation detectors to detect MeV-scale neutrons in the proton-recoil channel.