Optimizing the $^{8}$Li yield for the IsoDAR Neutrino Experiment

TL;DR

This paper investigates methods to enhance the production of $^{8}$Li isotopes, which are crucial for generating electron-antineutrinos in the IsoDAR experiment, by testing different sleeve materials to improve yield.

Contribution

It introduces optimized sleeve material configurations, notably a Li-Be mixture, to significantly increase $^{8}$Li yield for the IsoDAR neutrino source.

Findings

Li-Be sleeve increases $^{8}$Li yield substantially.

Material optimization can improve neutrino source performance.

Design modifications are motivated by yield enhancement results.

Abstract

The focus of this paper is on optimizing the electron-antineutrino source for the IsoDAR (Isotope Decay at Rest) experimental program. IsoDAR will perform sensitive short-baseline neutrino oscillation and electroweak measurements, among other Beyond Standard Model searches, in combination with KamLAND and/or other suitable detectors. IsoDAR will rely on the high-$Q$ $\beta^-$ decay of the $^{8}$Li isotope for producing electron-antineutrinos, created mainly via neutron capture in an isotopically enriched $^{7}$Li sleeve surrounding the Be target. In particular, this paper examines the performance, defined in terms of absolute $^{8}$Li (or, equivalently, electron-antineutrino) production rate, of various candidate sleeve materials, including a lithium-fluoride, beryllium-fluoride mixture ("FLiBe") sleeve and a homogeneous mixture of lithium and beryllium ("Li-Be"). These studies show that the $^{8}$Li yield can be increased substantially by employing a Li-Be sleeve and therefore motivate significant changes to the nominal IsoDAR design.