Demonstration of ThGEM-multiwire hybrid charge readout for directional dark matter searches

摘要

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 138 ± 10 ms~(-1) in a reduced drift field E/N of 93 ± 10~(-17) Vcm~2 with an effective gas gain of 2470 ± 160 in 20 Torr of pure SF_6 target gas.