# INSTR'20

24-28 February 2020
Budker Institute of Nuclear Physics
Asia/Novosibirsk timezone

## Observation of unusual slow components in electroluminescence signal of two-phase argon detector

27 Feb 2020, 12:00
20m
Contributed Oral Instrumentation for Astroparticle and Neutrino physics

### Speaker

Mr Egor Frolov (Budker Institute of Nuclear Physics SB RAS)

### Description

Proportional electroluminescence (EL) in noble gases is used in two-phase detectors for dark matter search to record ionization signals in the gas phase induced by particle scattering in the liquid phase (S2 signals). In this work, the EL pulse shapes in a two-phase argon detector have for the first time been studied systematically in a wide electric field range varying from 3 to 9 Td. The pulse shapes were studied at different readout configurations and spectral ranges: using cryogenic PMTs and SiPMs, with and without a wavelength shifter (WLS), in the VUV and visible range. We observed the fast component and two unusual slow components, with time constants of about 5 $\mu$s and 70 $\mu$s. The unusual characteristic property of slow components was that their contribution increased with field. We also show that the fast component may be used to measure the EL gap thickness with sub-mm resolution. The results obtained can have practical applications in DarkSide dark matter search experiment.

### Primary author

Mr Egor Frolov (Budker Institute of Nuclear Physics SB RAS)

### Co-authors

Dr Alexander Bondar (Budker Institute of Nuclear Physics SB RAS) Prof. Alexey Buzulutskov (Budker Institute of Nuclear Physics) Mr Andrey Sokolov (Budker INP) Mrs Ekaterina Borisova (Budker Institute of Nuclear Physics SB RAS) Mr Valery Nosov (Budker Institute of Nuclear Physics SB RAS) Mr Vladislav Oleynikov (Budker Institute of Nuclear Physics SB RAS)

### Presentation Materials

 Talk_E.Frolov_ArS2SlowComponent.pdf Talk_E.Frolov_ArS2SlowComponent.ppt