Engineering Design and Prototyping of the New LIU PS Internal Beam Dumps

For the LHC Injectors Upgrade (LIU) at CERN, the two Proton Synchrotron (PS) internal dumps are redesigned and upgraded for the new high intensity/brightness beams. The dumps are installed as active elements in the lattice in straight sections between the main bending magnets. The dumps are moved into the beam when requested by operation and shave the circulating beam turn by turn stopping the beam after about 6 ms. The shaving induces a very localized beam energy deposition on the dump surface in a thickness of tens of microns. A completely new approach has been developed with FLUKA to simulate beam shaving, coupled with ANSYS to define a new dump core design. This paper presents the design of the dump based on operational constraints such as cycling 200 000 times per year for 20 years, limited access for maintenance or reaching the beam trajectory in 150 ms. These constraints had a major impact on the technological choices. The new dump core is made of a low-density graphite block followed by a denser copper alloy (CuCr1Zr) one. Water circuits, bonded with Hot Isostatic Pressing, are cooling the core in ultra-high vacuum. The core is moved by a spring-based actuation mechanism.