公开(公告)号：US3567948A

公开(公告)日：1971-03-02

申请号：US3567948D

申请日：1969-04-14

Applicant: US NAVY

Inventor： OKE JOHN B ,  SCHILD RUDOLPH E

IPC: H01J40/06 ,  H01J43/28 ,  H01J39/12

CPC classification number: H01J40/06 ,  H01J43/28

Abstract: An end-on photomultiplier tube has a fused quartz dome covering its light-receiving face plate or window and further has its photocathode interfaced with the window and with the tube vacuum. The dome is a partial hemisphere so shaped that, in combination with the window thickness, the two members form a true hemisphere centered on the cathode. An incident light beam passing through the dome and directed onto the cathode center is reflected back into the dome from both the inner and outer interfaces of the cathode. The exterior surface of the dome lying in the path of these reflected beams is aluminized and, since the radius of curvature of the dome is centered on the cathode, these reflected beams are normal to the aluminized surface and thus re-reflected and reimaged back onto the cathode center. The arrangement achieves quantum efficiency gains by permitting a multiple photon traversal of the cathode and by controlling the angle of incidence to promote maximum interface reflectance. Also the reduction in size of the effective photocathode area minimizes photomultiplier dark current.