Benchmark of numerical tools simulating beam propagation and secondary particles in ITER NBI

Injection of high energy beams of neutral particles is a method for plasma heating in fusion devices. The ITER injector, and its prototype MITICA (Megavolt ITER Injector and Concept Advancement), are large extrapolations from existing devices. Therefore nu merical modeling is needed to set thermo - mechanical requirements for all beam - facing components. As the power and charge deposition originates from several sources (primary beam, co - accelerated electrons, and secondary production by beam - gas, beam - surface, and electron - surface interaction), the beam propagation along the beam line is simulated by comprehensive 3D models. This paper presents a comparative study between two codes: BTR has been used for several years in the design of the ITER HNB components; the SAMANTHA code was independently developed and includes additional phenomena, like secondary particles generated by collision of beam particles with the background gas. The code comparison is valuable in the perspective of the upcoming experimental oper ations, in order to prepare a reliable numerical support to the interpretation of experimental measurements in the beam test facilities. The power density maps calculated on the Electrostatic Residual Ion Dump (ERID) is chosen as the benchmark, as they dep end on the electric and magnetic fields as well as on the evolution of the beam species via interaction with the gas. Finally the paper shows additional results provided by SAMANTHA, like the power deposition onto the Cryopumps due to secondary electrons accelerated by the ERID fringe - field