Preliminary study of feasibility of an experiment looking for excited double beta transitions in tin

An attempt to study the feasibility of a new experiment to search for double beta decay in 112Sn and 124Sn was carried out by using ultra-low background HPGe detector (244 cm3) inside the Gran Sasso National Laboratory (LNGS) of the INFN (Italy). A small sample of natural Sn was examined for 2367.5 h. The radioactive contamination of the sample has been estimated. The data has also been considered to calculate the present sensitivity for the proposed search; half-life limits ~10^17–10^18 years for β+EC and EC–EC processes in 112Sn and ~10^18 years for β−β− transition in 124Sn were measured. In the last section of the paper the enhancement of the sensitivity for a proposed experiment with larger mass to reach theoretically estimated values of half-lives is discussed.