Update on the ANAIS experiment. ANAIS-0 prototype results at the new Canfranc Underground Laboratory

Update on the ANAIS experiment. ANAIS-0 prototype results at the new Canfranc Underground Laboratory. J Amaré, S Cebrián, C Cuesta, D Fortuño, E García, C Ginestra, H Gómez, M Martínez, M A Oliván, Y Ortigoza, A Ortiz de Solórzano, C Pobes, J Puimedón, M L Sarsa and J A Villar. Journal of Physics: Conference Series . 2012, Vol. 375

ANAIS experiment will look for dark matter annual modulation using NaI(Tl)
scintillators at the Canfranc Underground Laboratory (LSC). Highly purified NaI(Tl) crystals
are being developed to reach the required sensitivity. In a parallel way, the ANAIS-0 module
(made with a low background St Gobain NaI(Tl) crystal) has been taking data at the LSC,
testing different configurations: various photomultiplier tubes (PMTs) models with/without
light guides. Low background PMTs with light guides and ultra low background PMTs without
light guides have shown a similar contribution to the background. A complete simulation of the
ANAIS-0 module with shielding in the different configurations tested has been carried out and
compared with the experimental data, considering contributions to the background from NaI
bulk contaminants, PMTs, light guides, quartz windows and shielding materials. A good
understanding of the background above 500 keV can be reported.