Measurement of scintillation and ionization yield with high-pressure gaseous mixtures of Xe and TMA for improved neutrinoless double beta decay and dark matter searches

Abstract

The gaseous Xenon(Xe) time projection chamber (TPC) is an attractive detector technique for neutrinoless double beta decay and WIMP dark matter searches. While it is less dense compared to Liquid Xe detectors, it has intrinsic advantages in tracking capability and better energy resolution. The performance of gaseous Xe can be further improved by molecular additives such as trimethylamine(TMA), which is expected to (1) cool down the ionization electrons, (2) convert Xe excitation energy to TMA ionizations through Penning transfer, and (3) produce scintillation and electroluminescence light in a more easily detectable wavelength (300 nm). In order to test the feasibility of the performance improvements with TMA, we made the first direct measurement of Penning and fluorescence transfer efficiency with gaseous mixtures of Xe and TMA. While we observed a Penning transfer efficiency up to ~35%, we found strong suppression of primary scintillation light with TMA. We also found that the primary scintillation light with Xe and TMA mixture can be well characterized by ~3% fluorescence transfer from Xe to TMA, with further suppression due to TMA self-quenching. No evidence of the scintillation light produced by recombination of TMA ions was found. This strong suppression of scintillation light makes dark matter searches quite challenging, while the possibility of improved neutrinoless double beta decay searches remains open. This work has been carried out within the context of the NEXT collaboration.

arXiv comment9 pages, 6 figures, prepared for the proceedings of LIght Detection In Noble Elements (LIDINE 2015) conference. Updating with the version accepted by JINST

References in corpus (4)

• Accurate gamma and MeV-electron track reconstruction with an ultra-low diffusion Xenon/TMA TPC at 10 atmospheres
• Ionization and scintillation of nuclear recoils in gaseous xenon
• Modelling the behaviour of microbulk Micromegas in Xenon/trimethylamine gas
• Micro-physics simulations of columnar recombination along nuclear recoil tracks in high-pressure Xe gas for directional dark matter searches

Cited by in corpus (5)

• Gaseous and dual-phase time projection chambers for imaging rare processes
• Neutral Bremsstrahlung emission in xenon unveiled
• Microscopic simulation of xenon-based optical TPCs in the presence of molecular additives
• Electron Drift and Longitudinal Diffusion in High Pressure Xenon-Helium Gas Mixtures
• Study of the loss of Xenon Scintillation in Xenon-Trimethylamine Mixtures