1210.0649 (A. Bondar et al.)

Two-phase Cryogenic Avalanche Detectors with THGEM and hybrid THGEM/GEM
multipliers operated in Ar and Ar+N2    [PDF]

A. Bondar, A. Buzulutskov, A. Dolgov, A. Grebenuk, E. Shemyakina, A. Sokolov, D. Akimov, A. Breskin, D. Thers

Two-phase Cryogenic Avalanche Detectors (CRADs) with GEM and THGEM multipliers have become an emerging potential technique for charge recording in rare-event experiments. In this work we present the performance of two-phase CRADs operated in Ar and Ar+N2. Detectors with sensitive area of 10x10 cm2, reaching a litre-scale active volume, yielded gains of the order of 1000 with a double-THGEM multiplier. Higher gains, of about 5000, have been attained in two-phase Ar CRADs with a hybrid triple-stage multiplier, comprising of a double-THGEM followed by a GEM. The performance of two-phase CRADs in Ar doped with N2 (0.1-0.6%) yielded faster signals and similar gains compared to the operation in two-phase Ar. The applicability to rare-event experiments is discussed.

View original: http://arxiv.org/abs/1210.0649