Design of the proton beam line for the TRADE experiment

The TRADE (TRIGA Accelerator Driven Experiment) experiment, to be performed in the TRIGA reactor of the ENEA-Casaccia Centre, consists in the coupling of a 140 MeV - 1 mA beam, produced by a cyclotron to a target hosted in the central thimble of the reactor scrammed to sub-criticality. A 30 m long beam line has been designed to transfer the beam injecting it from the pool's top with special care of having very low losses in the TRIGA reactor building where a limited shielding of the beam line is possible. The beam transfer line has been divided in three main parts: the Matching Section, that reduces the cyclotron beam size and matches the beam to the other sections, the Straight Transfer Line that brings the beam to the top of the pool and the Final Bending that shapes and directs the beam onto the target. Attention was paid to reduce the number and size of elements of the FB section that are immersed in the pool's water. Shielding calculations show that a sustainable radiation level is obtainable with the foreseen beam losses. The paper presents a description of the beam line, of the mechanical support, of the shielding structure and the results of computations.