Thermal experimental results on the prototype for high power neutron converter for low energy proton/deuteron beams

In the framework of the European program aimed at the developing of a second generation radioactive ion beam (RIB) facility, the Legnaro National Laboratories (LNL) propose in the next few years the construction of a specialized national facility for RIB originated by fission fragments produced by fast neutrons (SPES). Protons/deuterons of 40 MeV (150 kW) will produce about 1014 neutrons per second in a converter with energy centered at around 14 MeV which will induce fission in a suitable fissile target, with the aim of 1013 fissions per second at least. A rotating target includes the converter made of 13C-based material or natural carbon (for proton and deuteron beams, respectively), and cooled mainly by thermal radiation. This paper presents the design of the prototype, as well as the thermal experimental results with high-power electron beams. The prototype comprises the carbon-made neutron converter mounted on the rotating metal disk of 30 cm in diameter and designed to dissipate 50 kW of beam power at nominal operation condition. The test consists of the prototype converter irradiation with the high-power electron beam (beam size below 1 cm) of the ELV-6 accelerator. The prototype successfully remained under nominal conditions. In addition, the prototype was submitted to a beam power of 70 kW, which exceeds of 40% the design power, without any appreciable damage on the converter material. The results are in good agreement with the numerical simulations.