The selection of low-radioactive construction materials is of the utmost importance for rare-event searches and thus critical to the XENONnT experiment. Results of an extensive radioassay program are reported, in which material samples have been screened with gamma-ray spectroscopy, mass spectrometry, and Rn-222 emanation measurements. Furthermore, the cleanliness procedures applied to remove or mitigate surface contamination of detector materials are described. Screening results, used as inputs for a XENONnT Monte Carlo simulation, predict a reduction of materials background (similar to 17%) with respect to its predecessor XENON1T. Through radon emanation measurements, the expected Rn-222 activity concentration in XENONnT is determined to be 4.2 (-(+0.5)(0.7)) mu Bq/kg, a factor three lower with respect to XENON1T. This radon concentration will be further suppressed by means of the novel radon distillation system.
Material radiopurity control in the XENONnT experiment
D'Andrea, VMembro del Collaboration Group
;Ferella, A DMembro del Collaboration Group
;Macolino, CMembro del Collaboration Group
;
2022-01-01
Abstract
The selection of low-radioactive construction materials is of the utmost importance for rare-event searches and thus critical to the XENONnT experiment. Results of an extensive radioassay program are reported, in which material samples have been screened with gamma-ray spectroscopy, mass spectrometry, and Rn-222 emanation measurements. Furthermore, the cleanliness procedures applied to remove or mitigate surface contamination of detector materials are described. Screening results, used as inputs for a XENONnT Monte Carlo simulation, predict a reduction of materials background (similar to 17%) with respect to its predecessor XENON1T. Through radon emanation measurements, the expected Rn-222 activity concentration in XENONnT is determined to be 4.2 (-(+0.5)(0.7)) mu Bq/kg, a factor three lower with respect to XENON1T. This radon concentration will be further suppressed by means of the novel radon distillation system.Pubblicazioni consigliate
I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
