Speaker
Description
The NEWS-G experiment aims for the direct detection of low mass Weakly Interacting
Massive Particle (WIMP) dark matter using Spherical Proportional Counters (SPC). At the center of the SPC, a small sensor held at high voltage drives the drift of the primary ionization and provide the amplification needed to detect sub-keV nuclear recoils down to single electrons. The ACHINOS is a novel multi-channel sensor at the center of the SPC that allows for high amplification and better primary ionization collection thanks to enhanced electric fields at larger radius. The current implementation of ACHINOS in the NEWS-G SPC has two channels that separate the active volume in to distinct volumes, namely north and south. An improved version of ACHINOS sensor with three channels is set to be used for the NEWS-G experiment at SNOLAB in Spring 2021. Future implementation of ACHINOS with multi-channel readout could allow for the directional measurement of dark matter in a large, low-pressure SPC. In this talk, the operating principle of the ACHINOS sensor will be presented together with the study of cross-talk and fiducial volume.
