The selection of low-radioactive construction materials is of utmost importance for the success of low- energy rare event search experiments. Besides radioactive contaminants in the bulk, the emanation of radioactive radon atoms from material surfaces attains increasing relevance in the effort to further reduce the background of such experi- ments. In this work, we present the 222 Rn emanation mea- surements performed for the XENON1T dark matter exper- iment. Together with the bulk impurity screening campaign, the results enabled us to select the radio-purest construc- tion materials, targeting a 222 Rn activity concentration of 10 μBq/kg in 3.2 t of xenon. The knowledge of the distri- bution of the 222 Rn sources allowed us to selectively elim- inate problematic components in the course of the exper- iment. The predictions from the emanation measurements were compared to data of the 222 Rn activity concentration in XENON1T. The final 222 Rn activity concentration of (4.5 ± 0.1) μBq/kg in the target of XENON1T is the lowest ever achieved in a xenon dark matter experiment.

222 Rn emanation measurements for the XENON1T experiment

Di Stefano R.;Marignetti F.;Messina M.;
2021-01-01

Abstract

The selection of low-radioactive construction materials is of utmost importance for the success of low- energy rare event search experiments. Besides radioactive contaminants in the bulk, the emanation of radioactive radon atoms from material surfaces attains increasing relevance in the effort to further reduce the background of such experi- ments. In this work, we present the 222 Rn emanation mea- surements performed for the XENON1T dark matter exper- iment. Together with the bulk impurity screening campaign, the results enabled us to select the radio-purest construc- tion materials, targeting a 222 Rn activity concentration of 10 μBq/kg in 3.2 t of xenon. The knowledge of the distri- bution of the 222 Rn sources allowed us to selectively elim- inate problematic components in the course of the exper- iment. The predictions from the emanation measurements were compared to data of the 222 Rn activity concentration in XENON1T. The final 222 Rn activity concentration of (4.5 ± 0.1) μBq/kg in the target of XENON1T is the lowest ever achieved in a xenon dark matter experiment.
File in questo prodotto:
File Dimensione Formato  
Aprile2021_Article_222222RnEmanationMeasurementsF.pdf

solo utenti autorizzati

Licenza: Copyright dell'editore
Dimensione 826.51 kB
Formato Adobe PDF
826.51 kB Adobe PDF   Visualizza/Apri   Richiedi una copia

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11580/90610
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 26
social impact