Constraints due to the production of radioactive ion beams in the SPIRAL project

Abstract

The radioactive ion beams that will be delivered by the SPIRAL facility will be produced by the interaction of a stable high energy (95 MeV/A) and high intensity (2×1013 particle/s) primary ion beam delivered by the GANIL cyclotrons with a carbon target heated to 2000 °C. During this interaction, some radioactive atoms will be created and will diffuse out of the target before entering into an electron cyclotron resonance (ECR) ion source where they will be ionized and extracted. The production of radioactive ion beams with this method implies high radiation fields that activate and can damage materials located in the neighborhood of the target. Therefore, the production system which is composed of the permanent magnet ECR ion source coupled to a graphite target will be changed after two weeks of irradiation. As this ensemble will be very radioactive, this operation has to be supervised by remote control. The radiation levels around the target–ion source system and a detailed description of the different precautions that have been taken for safety and for prevention of contamination and irradiation are presented.