Test Results of PIP2IT MEBT Vacuum Protection System

Abstract: The central part of PIP-II program of upgrades pro-posed for the Fermilab injection complex is an 800 MeV, 2 mA, CW-compatible SRF linac. Acceleration in super-conducting cavities begins from a low energy of 2.1 MeV, so that the first cryomodule, Half Wave Resonator (HWR) borders the warm Medium Beam Transport (MEBT) line. To minimize the amount of gas that may enter the SRF linac in a case if a vacuum failure occurs in the warm front end, a vacuum protection system is envisioned to be used in the PIP-II MEBT. It features a fast closing valve with two sensors and a differential pumping insert. The system prototype was installed in the PIP-II Injector Test (PIP2IT) accelerator and successfully tested in several modes modelling the vacuum failures. The report presents the design of the vacuum protection system and results of its tests.