Thermal neutron–induced γ-ray background in 124Sn

The thermal neutron-induced gamma-ray background in 124Sn is investigated in connection with neutrinoless double beta decay (0νββ) 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*(32+) and 125Sn(112−) 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 Qββ value of 124Sn (~2.291 MeV) is discussed.