Thermal neutron–induced γ-ray background in 124Sn

Abstract The thermal neutron-induced gamma-ray background in 124Sn is investigated in connection with neutrinoless double beta decay (0 ν β β ) studies in 124Sn. For this purpose, a 99.26 % enriched 124Sn sample was irradiated with a thermal neutron fluence of 3 × 1015/cm2 in the Dhruva reactor at the Bhabha Atomic Research Centre, Mumbai. The gamma ray spectra of the irradiated sample were measured in a low background counting setup to study both long-lived and short-lived activities. The present data give an independent measurement of the half-life of 125Sn*( 3 2 + ) and 125Sn( 11 2 − ) as 10.01(8) min and 9.63(2) d, respectively. The impact of the observed high-energy gamma rays and the residual activity due to 125Sb, on the background in the region of interest around the Q β β value of 124Sn ( ∼ 2.291 MeV) is discussed.