Radiation Tolerant Programmable Power Supply for the LHC Beam Screen Heaters

For the next LHC run, it is required to install 200 W ofheating capacity per LHC beam screen heater to regenerate the beamscreen by desorption of gas trapped on its walls. In the LHC, thereare 272 beam screen heaters and the associated electronics limitpresently the heating capacity to 25 W. Those electronics are, forthe most part, installed inside the LHC tunnel and exposed to itsradiation environment.This paper describes the development of a new programmable powersupply card that will be integrated into the existing LHC radiationtolerant electronic infrastructure used by the cryogenicsystem. Radiation tests were undertaken to qualify a power switchcapable of coping with the 230 Vrms grid voltage and an analogsignal multiplexer; these components are required respectively forsatisfying the higher power requirements and for reducing theoverall cost by using a single analog to digital converter to sampleall the signals.