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 $2470\pm 160$ in 20 Torr of pure SF${}_{\text{6}}$ target gas.

17 pages, 18 figures