A radiation tolerant phototube power supply for the electromagnetic calorimeter of the HERA-BB experiment

The design of the phototube power supply for the HERA-BB  Electromagnetic Calorimeter is presented. A choice of the solution on the basis of the Cockcroft–Walton voltage multiplier is validated. Schematics developed are discussed. A special section describes the behaviour of the crucial components under irradiation since radiation tolerance becomes one of the most important items in the severe HERA-BB  radiation environment. Finally, performance achieved is presented.