Photomultiplier with magnetic shielding case

摘要

The present invention relates to a magnetic shielding case comprising a structure for improving the uniformity in light receiving sensitivity of a phomultiplier while maintaining sufficient magnetic shielding function, and a light detecting apparatus including this magnetic shielding case. This apparatus comprises a photomultiplier and a magnetic shielding case accommodating the photomultiplier. In particular the magnetic shielding case comprises a housing having an opening for transmitting therethrough light to be detected which is directed to the photomultiplier; a lens element for guiding the light to be detected into an effective region on a photocathode; and a positioning structure for placing the photomultiplier at a desired position with respect to the lens element.