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

Understand

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.