The High Energy Beam Transport lines (HEBT) and the Beam Dump
The HEBT line transports the beam from the Linac to the beam dump includes a Diagnostics Plate for beam characterization, a bending magnet to reduce the neutron radiation from beam dump towards upstream components, a magnetic beam expander to limit the power density on the beam dump (< 200 kW/cm2), a lead shutter, closed during beam shutdown to act as a gamma shield from the activated beam dump and a beam scraper to protect the last portion of the vacuum pipe in front of the beam dump.
A conical dump made of copper has been designed to stop the 1.125 MW deuteron beam. It is cooled by a high velocity water flow that circulates through an annular channel along the outer surface of the cone. Thermo-mechanical studies showed a high robustness to beam errors, CW and pulsed mode operation, buckling and high velocity coolant flow effects. A local shielding made of water tanks and polyethylene against neutrons and iron blocks against gamma rays associated with an extra frontal shielding made of a 70 cm thick concrete wall to fulfil the radiological protection requirements: low dose rates outside the accelerator vault during accelerator operation and manual maintenance inside the accelerator vault possible during beam-off phases.