Design of Beam Dump for SPIDER facility

ITER Neutral Beam Test Facility (NBTF) is being built at Consorzio RFX, Padova, Italy. SPIDER (Source for Production of Ion of Deuterium Extracted from RF Plasma) facility is part of NBTF and consists of a 100 kV negative ions beam source that is used for the first phase of exploitation and development for the negative ion based ITER neutral beam injectors. A Beam Dump, which is designed for dumping all the beam power, will be used in SPIDER. Beam Dump will also be utilized for measuring thermal loads for beam diagnostics. Apart from design requirements, Beam Dump is supposed satisfy certain interface requirements like interface with SPIDER vessel, interface with cooling water plant, interface with neutron diagnostic boxes and interface with other diagnostics. Beam Dump design uses Hypervapotron based Heat Transfer Elements (HTEs) made up of CuCrZr alloy. HTEs are actively cooled high heat flux elements and are capable of removing heat fluxes as high as 10MW/m2. 31 HTEs in horizontal position are stacked vertically to form a frame. There are two frames arranged in V-shape with an angle between them being 60 C. The angle is kept essentially to limit the power density on each HTE as less than or equal to 10 MW/m2. Power density profiles on heat facing surfaces of Beam Dump are estimated by an empirical relation of double Gaussian distribution characterized by four parameters. Finite Element Analysis (FEA) is carried out on individual HTEs as well as on integrated structure in order to verify its ability to withstand the loads in different conditions. ITER Structural Design Criteria for In Vessel Components (SDC-IC) was used for structural design verification with respect operational conditions. This paper presents overview of design of SPIDER Beam Dump with particular emphasize on choice of heat removing elements, design compliance with operational and test requirements, provision for beam shine-through and compliance with interfaces.