Setting of the predefined multiplier gain of a photomultiplier

Abstract

A method to set the predefined PMT gain with high precision is described. The method supposes minimal participation of the operator. After the rough initial setting of the gain, the automated system adjusts the PMT gain within a predefined precision (up to 2%). The method has been successfully applied at the Borexino PMT test facility at LNGS for the gain adjustment of the 2000 photomultipliers for the Borexino detector