公开(公告)号：JPH1050200A

公开(公告)日：1998-02-20

申请号：JP12395997

申请日：1997-05-14

Applicant: IBM

Inventor： JIYON BIITESON ,  ANDORUU RAMUZEI NOTSUKUSU

IPC: H01J29/02 ,  H01J1/00 ,  H01J7/44 ,  H01J19/82 ,  H01J29/68 ,  H01J29/98 ,  H01J31/12 ,  H01J37/24 ,  H01J61/56

Abstract: PROBLEM TO BE SOLVED: To provide a vacuum electronic apparatus which can controllably measure electron beam flow by arranging a sensor electrode between a cathode which supplies electrons of electron beam and an anode which receives electrons and housing the resultant body in a vacuum tube. SOLUTION: A vacuum tube 10 houses an anode 30, a cathode 20, and a conductive plate 40. During operation, the anode 30 is held at higher or equal potential than the cathode 20 and electrons emitted out of the cathode 20 pass the tube 10 toward the anode 30. The conductive plate 40 is connected to a detection circuit 50 arranged in the inside or the outside of the apparatus. Due to electrons which collide against the conductive plate 40 during the operation, electric current flowing from the circuit 50 to the conductive plate 40 is generated. By controlling the potential of the conductive plate 40 to be the necessary potential to balance an electrostatic field, the disturbance to the electrostatic field in the peripheral area of the conductive plate 40 is suppressed to the minimum limit. Consequently, electron beam flow between the anode 30 and the cathode 20 can be measured.