Neutrinoless Double Beta Decay with $^{82}$SeF$_6$ and Direct Ion Imaging

TL;DR

This paper proposes a novel neutrinoless double beta decay detector using high pressure selenium hexafluoride gas in a time projection chamber, combining topological discrimination with the isotope's high Q-value for improved detection.

Contribution

It introduces a new detection concept utilizing SeF6 gas TPC with ion drift, addressing the lack of free electrons and exploring ion microphysics for background reduction.

Findings

Potential background index below 1 count per ton per year

Feasibility of high-pressure SeF6 TPC for double beta decay detection

Enhanced sensitivity at ton-scale detectors

Abstract

We present a new neutrinoless double beta decay concept: the high pressure selenium hexafluoride gas time projection chamber. Combining techniques pioneered in high pressure xenon gas such as topological discrimination, with the high Q-value afforded by double beta decay isotope $^{82}$Se, a promising new detection technique is outlined. Lack of free electrons in SeF$_6$ mandates the use of an ion TPC. The microphysics of ion production and drift, which have many nuances, are explored. Background estimates are produced suggesting such a detector may achieve background indices of better than 1 count per ton per year in the region of interest at the 100~kg scale, and still better at the ton-scale.