Speaker
Andrea Pocar
(UMass Amherst)
Description
Liquid xenon detectors are at the forefront of rare event physics, including searches for neutrino-less double beta decay and WIMP dark matter. The xenon for these experiments needs to be purified from chemical impurities such as electronegative atoms and molecules, which absorb ionization electrons, and VUV (178 nm) scintillation light-absorbing chemical species. In addition, superb purification from radioactive impurities is required. Particularly challenging are radioactive noble isotopes (Kr-85, Ar-39/42, Rn-222/220). Radon is a particularly universal problem, due to the extended decay sequence of its daughters and it’s ubiquitous presence in detector materials. Purification and de-radonation of liquid xenon will be addressed with particular focus on the experience gained with the EXO-200 neutrino-less double beta decay detector. Related issues with radon in the vicinity of the detectors will be discussed as time allows.
Primary author
Andrea Pocar
(UMass Amherst)
