First reconstruction of absolute three-dimensional position of nuclear recoils using a negative ion $\mu$-TPC for dark matter search experiments

TL;DR

This paper demonstrates the first successful 3D absolute position reconstruction of nuclear recoils in a negative ion micro TPC, advancing directional dark matter detection capabilities.

Contribution

It develops a negative ion micro TPC with dedicated electronics and achieves 70% efficiency in 3D position reconstruction of nuclear recoils.

Findings

Achieved 70% efficiency in 3D absolute position reconstruction.

Demonstrated capability of the NIμTPC for direction-sensitive dark matter searches.

Marked progress towards practical use of NIμTPCs in dark matter experiments.

Abstract

Studies of micro time projection chambers using negative ion gas (NI$\mu$TPC) are conducted especially for direction-sensitive dark matter searches. A NI$\mu$TPC enables to measure the absolute position in the drift direction for self-triggering TPCs. This study provides a development of a NI$\mu$TPC using a micro pixel chamber ($\mu$-PIC) with dedicated readout electronics, and an evaluation of the capability of three-dimensional absolute position reconstruction of nuclear recoil using a neutron source. The absolute track position was reconstructed throughout the drift volume with an efficiency of 70$\pm$5%. This work marks an important step for the NI$\mu$TPCs towards the practical use for directional dark matter searches.