Demonstration of ThGEM-Multiwire Hybrid Charge Readout for Directional Dark Matter Searches

Abstract

Sensitivities of current directional dark matter search detectors using gas time projection chambers are now constrained by target mass. A ton-scale gas TPC detector will require large charge readout areas. We present a first demonstration of a novel ThGEM-Multiwire hybrid charge readout technology which combines the robust nature and high gas gain of Thick Gaseous Electron Multipliers with lower capacitive noise of a one-plane multiwire charge readout in SF$_6$ target gas. Measurements performed with this hybrid detector show an ion drift velocity of $139~\pm~12~\text{ms}^{-1}$ in a reduced drift field $\text{E/N}$ of $93~\text{Td}~(10^{-17}~\text{V cm}^{2})$ at a gas gain of $2470\pm160$ in 20 Torr of pure SF$_\text{6}$ target gas.