Proposed low-energy absolute calibration of nuclear recoils in a dual-phase noble element TPC using D-D neutron scattering kinematics

TL;DR

This paper introduces a novel in situ calibration method for nuclear recoils in noble element TPCs, enhancing low-mass WIMP detection sensitivity by reducing systematic uncertainties using neutron scattering kinematics.

Contribution

It presents a new calibration technique based on neutron scattering angles and discusses improvements including a quasi-monoenergetic neutron source for better low-energy recoil measurement.

Findings

Confirmed suitability of the DD108 neutron generator for calibration

Demonstrated reduced systematics in low-energy recoil measurement

Proposed improvements for calibration accuracy

Abstract

We propose a new technique for the calibration of nuclear recoils in large noble element dual-phase time projection chambers used to search for WIMP dark matter in the local galactic halo. This technique provides an $\textit{in situ}$ measurement of the low-energy nuclear recoil response of the target media using the measured scattering angle between multiple neutron interactions within the detector volume. The low-energy reach and reduced systematics of this calibration have particular significance for the low-mass WIMP sensitivity of several leading dark matter experiments. Multiple strategies for improving this calibration technique are discussed, including the creation of a new type of quasi-monoenergetic 272 keV neutron source. We report results from a time-of-flight based measurement of the neutron energy spectrum produced by an Adelphi Technology, Inc. DD108 neutron generator, confirming its suitability for the proposed nuclear recoil calibration.