Speaker
Dr
Kyohei Nakajima
(Osaka University)
Description
CANDLES is a neutrino less double beta decay (0νββ) experiment using 48Ca in CaF2 crystals. A distinctive characteristic of 48Ca is the highest Q value (4.3 MeV) among isotope candidates for 0νββ. In principle, it enables us to measure signals in small background contribution. The background candidates in interested energy region are β/γ rays from 208Tl (Q = 5.0 MeV), and 212Bi-212Po coincidence (E_beta = 2.2 MeV, visible E_alpha = 3.1 MeV) which decays in a short time window (T_1/2 = 299 nsec). In addition, we found that gamma rays from neutron captures on materials surrounding detector can be dominant background. Here we discuss these background estimation and prospects of backgrounds shielding.
Primary author
Dr
Kyohei Nakajima
(Osaka University)