Assessment of backgrounds of the ANAIS experiment for dark matter direct detection

Amaré, J. (Universidad de Zaragoza) ; Cebrián, S. (Universidad de Zaragoza) ; Cuesta, C. ; García, E. (Universidad de Zaragoza) ; Martínez, M. ; Oliván, M.A. (Universidad de Zaragoza) ; Ortigoza, Y. ; Ortiz de Solorzano, A (Universidad de Zaragoza) ; Puimedón, J. (Universidad de Zaragoza) ; Sarsa, M.L. (Universidad de Zaragoza) ; Villar, J.A. (Universidad de Zaragoza) ; Villar, P. (Universidad de Zaragoza)

Resumen: A large effort has been carried out to charac- terize the background of sodium iodide crystals within the Annual modulation with NaI Scintillators (ANAIS) project. In this paper, the background models developed for three 12.5 kg NaI(Tl) scintillators produced by Alpha Spectra Inc. and operated at the Canfranc Underground Laboratory are presented together with an evaluation of the background prospects for the full experiment. Measured spectra from threshold to high energy in different conditions are well described by the models based on quantified activities. At the region of interest, crystal bulk contamination is the dominant background source. Contributions from 210 Pb, 40 K, 22 Na and 3 H are the most relevant. Those from 40 K and 22 Na could be efficiently suppressed thanks to anticoincidence operation in a crystals matrix or inside a liquid scintillator veto (LSV), while that from 210Pb has been reduced by improving crystal production methods and 3H production could be reduced by shielding against cosmic rays during production. Assuming the activities of the last characterized detector, for nine crys- tals with a total mass of 112.5 kg the expected background rate is 2.5 counts/(keV kg day) in the region from 1 to 4 keV, which could be reduced at 1.4 counts/(keV kg day) by using a LSV.

Idioma: Inglés

DOI: 10.1140/epjc/s10052-016-4279-2

Año: 2016

Publicado en: European Physical Journal C 76, 429 (2016), [15 pp.]
ISSN: 1434-6044

Factor impacto JCR: 5.331 (2016)

Categ. JCR: PHYSICS, PARTICLES & FIELDS rank: 4 / 29 = 0.138 (2016) - Q1 - T1

Factor impacto SCIMAGO: 1.653 - Physics and Astronomy (miscellaneous) (Q1) - Engineering (miscellaneous) (Q1)

Financiación: info:eu-repo/grantAgreement/ES/MICINN/CPAN-CSD2007-00042
Financiación: info:eu-repo/grantAgreement/ES/MINECO/Consolider-Ingenio2010-MULTI-DARK-CSD2009-00064
Financiación: info:eu-repo/grantAgreement/ES/MINECO-FEDER/FPA2011-23749
Financiación: info:eu-repo/grantAgreement/ES/MINECO-FEDER/FPA2014-55986-P

Tipo y forma: Article (Published version)

Área (Departamento): Área Ingen.Sistemas y Automát. (Dpto. Informát.Ingenie.Sistms.)
Área (Departamento): Área Técnica. Lab. y Talleres (Dpto. Física Teórica)
Área (Departamento): Área Óptica (Dpto. Física Aplicada)
Área (Departamento): Área Física Atóm.Molec.y Nucl. (Dpto. Física Teórica)