Measurement of cosmogenic radioactive products in xenon and copper

6th Young Researcher Meeting, L'Aquila 2015

Piastra, Francesco^1

Department of Physics, University of Zürich, Winterthurerstrasse 190, Zürich

CH-8057, Switzerland^1

关键词: Dark matter detection;    Dark matter searches;    Dedicated measurements;    Detector components;    Gamma ray spectrometry;    Neutrinoless double-beta decays;    Production rates;    Research stations;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/689/1/012021/pdf
DOI  :  10.1088/1742-6596/689/1/012021

来源: IOP

【 摘 要 】

Rare events searches, such as direct dark matter detection or neutrinoless double beta decay (0vββ) observation, using liquid xenon as target and detection medium require ultralow background to fully exploit the physics potential. Cosmogenic activation of the detector components, and even more importantly, of the xenon itself might have undesired impact on the background and the final sensitivity of the experiment. Since no measurement of cosmogenic activation of xenon was present in literature so far, we performed such a measurement exposing of a natural xenon sample to the cosmic radiation at the Jungfraujoch research station at an altitude of 3470 m above sea level for 245 days. This study was complemented with a ultra pure copper sample that was activated together with the xenon. We directly observed, with gamma-ray spectrometry, the production of7Be,101Rh,125Sb,126I and127Xe in xenon, out of which only125Sb could potentially lead to a background relevant for multi-ton scale direct dark matter search. The production rates for five out of eight radioactive isotopes in copper are in good agreement with the only dedicated measurement present in literature. The production rates measured for both samples were compared with the predictions obtained with commonly used software packages. The latter showed a systematic under-estimation, especially for xenon.