PSB H0-H⁻ Monitor Calibration and Commissioning

During the LHC Long Shutdown 2 (LS2), the H⁻ LINAC4 replaced the proton LINAC2 as Proton Synchrotron Booster (PSB) injector. In each of the four PSB rings, the injection region was upgraded to accommodate the necessary elements for a proper H⁻ charge exchange injection systems. Four internal beam dumps (one per ring), installed downstream the stripping foil, block the unstripped H⁻ particles not injected in the ring. The H0-H⁻ monitors consists in 4 titanium plates placed few centimetres upstream of the dump, intercepting partially stripped H⁰ or not stripped H⁻ ions. They allow a continuous monitoring of the stripping efficiency and, connected to an interlock system, block the injection process in case of heavy degradation or breakage of the foil, which would heavily damage the dumps. The contribution will focus on the commissioning and operation these new systems. This will include the calibration campaigns, performed by comparison to beam current transformers during special periods with low intensity beams and no stripping foils. During normal operation it was already possible to monitor stripping inefficiencies below 1% and compare different beams and stripping foil types.