Development of coating furnace for Nb₃Sn SRF cavities and the first heating experiments

Deposition system of Nb₃Sn thin film by vapor diffusion has been developed at KEK. The deposition system consists of a coating chamber made of Nb, a vacuum furnace for heating a Nb chamber and a heating device of Tin in a crucible. Temperature distribution of the coating chamber and the Tin crucible was estimated by a thermal simulation code. The thermal design of the deposition system using the simulation results was confirmed by the heating experiments. After the deposition system was completed, the first deposition test of Nb₃Sn coating on Nb samples was carried out. In this paper, the results of the thermal simulations and the heating experiments are compered, and the first deposition results are reported. (author)