Low-pressure THGEM-based operation with Ne+H2 Penning mixtures

Abstract

Operation of Thick Gas Electron Multipliers (THGEMs) in Time Projection Chambers (TPCs) using various gas mixtures find applications in various nuclear physics and particle detection experiments. Of particular interest are use of neon-based gas mixtures at low pressures in TPCs as active targets for radioactive beams. Here, we report on the low pressure operation of THGEMs in Ne+H 2 based gas mixtures, where neon in this mixture is an important target for fusion studies with TPCs. We show that, since the Ne+H 2 forms a Penning pair, higher gains are achievable compared to pure neon gas. Moreover, H 2 as a quench-gas produces minimal background in fusion reactions compared to carbon-based neon gas mixtures. Detailed electron transport and amplification simulations have been performed and they qualitatively agree with the increased gain H 2 provides in the Ne:H 2 mixture. This allows for sufficiently high gains for the use of Ne gas with THGEMs that will enable the measurement of heavy-ion tracks for nuclear physics experiments at modest gas pressures.