Light Output Quenching in Response to Deuterium-ions and Alpha Particles and Pulse Shape Discrimination in Deuterated Trans-stilbene

TL;DR

This study characterizes the light output response and pulse shape discrimination capabilities of a new stilbene-d12 crystal for detecting various particles, demonstrating its potential for high-fidelity neutron detection and spectroscopy.

Contribution

The paper provides the first detailed experimental characterization of stilbene-d12's light response and PSD performance for deuterium ions and alpha particles, enabling improved detector modeling.

Findings

Light output is increasingly quenched with higher ionization density.

Birks' quenching parameter for alpha particles is about 8.5 times larger than for deuterium ions.

The detector exhibits excellent pulse shape discrimination capabilities.

Abstract

We characterized the light output response of a new 140 cm3 stilbene-d12 crystal up to 14.1 MeV neutron energies using a coincidence neutron scattering system. We also characterized its light output response to alpha particles in the 5 to 6~MeV energy range. The excellent PSD capability of the stilbene-d$_{12}$ detector allowed us to select light pulses produced by particles of increasing ionization density, namely electrons, protons, deuterium-ions, and alpha particles. The measured fast decay component of the light pulses is increasingly quenched as the ionization density of the particle in the crystal increases. Consistently with this finding, the Birks' quenching parameter of alpha particles is approximately 8.5 times larger compared to the quenching of deuterium ions, produced by neutron scattering interactions. The reported experimental characterization will allow high-fidelity modeling of the detector enabling its application for fast-neutron detection and spectroscopy in nuclear physics, radiation protection, nuclear security, and non-proliferation.