HVPS system for ∗ – EUSO detectors

In the JEM-EUSO focal instrument four multianode photomultipliers (Elementary Cell unit) are powered by one high voltage generator. The HV control system for Photo Detection Module consists of 9 high voltage generators. HV generators are Cockcroft-Walton voltage multipliers with protection system and with 3 level very fast switches for HV at cathodes. Protection systems were made to protect HVPS itself against possible excess of power consumption, but might be as well used as a protection of PMTs in case of unexpected enlighting. Externally controlled switches can reduce 100 times or 10000 times the PMT collection efficiency to enlarge the PMT dynamics up to factor 10 6 . The HV control unit provides galvanic insulation of HV system, and allows for input voltage in a range 15-35 V. Control unit provides interface for external voltage setting, control of switches, and emits information about the statuses of 9 HV generators.