Ion Drift in Multiwire Proportional Chambers

Abstract

The DRIFT dark matter detector (Directional Recoil Identification From Tracks) recently proposed by Snowden-Ifft and collaborators requires the use of ion drift to provide signal directionality. Carbon disulfide, an electronegative gas, has been suggested for use in such a detector because a heavy ion has less lateral diffusion than an electron in the drift field. A drift chamber attached to a multiwire proportional chamber and pulsed xenon light source was used to create photoelectrons to measure the lateral diffusion and drift speed. We were able to show that the ions have less diffusion than electrons and behave as predicted by theory. Further work is planned to determine ideal gas concentration and exploration of alternative gases.