Secondary electron multiplier

• US 4,987,335 A
• Filed: 08/11/1989
• Issued: 01/22/1991
• Est. Priority Date: 08/11/1988
• Status: Expired due to Term

• Current Assignee: Murata Manufacturing Co Limited
• Original Assignee: Murata Manufacturing Co Limited
• Inventors: Terashima, Takeshi, Yamamoto, Hiroshi
• Primary Examiner(s): Yusko, Donald J.
• Assistant Examiner(s): Horabik, Michael
• Application Number:
  US07/392,837
• Time in Patent Office: 529 Days
• Field of Search: 313/103 R, 313/103 CM, 250/207
• US Class Current: 313/103.00R
• CPC Class Codes: H01J 43/24 Dynodes having potential gradient along their surfaces
• CPC Class Codes: H01J 49/025 Detectors specially adapted to particle spectrometers data acquisition H01J49/0036; detectors per se G01T, e.g. G01T1/28, G01T1/29

Abstract

A structure for supporting a funnel portion of a secondary electron multiplying tube in a secondary electron multiplier. In the supporting structure for the funnel portion, a support member has a circular contact element for supporting an end face of a mouth of the funnel, and nails formed along the outer periphery of the circular contact element so as to grasp the mouth end portion of the funnel from the outside thereof. A press member is welded to the support member into which the funnel portion is inserted. The posture and position of the funnel portion are correctly determined in relation to an opening of a Farady cup, by fixing the support member to a casing of the secondary electron multiplier.

Claims

1. A secondary electron multiplier comprising a pair of insulating plates arranged in parallel with each other which are fixed by a face plate having an incident aperture for charged particles and a terminal plate member, a secondary electron multiplying tube having a funnel portion at the input end thereof which is made of a semiconductive material having a secondary electron emissive property and a collector for collecting a flow of secondary electrons multiplied by said multiplying tube wherein said secondary electron multiplying tube is supported between said pair of insulating plates in such a manner that the mouth of said funnel is inclined at a predetermined angle to an opening of a Faraday cup fixed at the rear side of said incident aperture of said face plate,

said secondary electron multiplier being characterized by further comprising a support metal member having a circular contact element for supporting an end face of said mouth of said funnel, plural nails formed along the outer periphery of said circular contact element for grasping said mouth of the funnel from outside thereof and a pair of support arms being extended from the outer periphery of said circular contact element toward said respective insulating plates, said support arms having portions bent along said insulating plates so as to fix them to said insulating plates, and

a press metal member to be fitted to the outer periphery of said funnel near the mouth thereof which is welded to said support metal member to support the funnel fixedly to said support metal member.