Cathode, electron beam emission apparatus using the same, and me

Details Cathode, electron beam emission apparatus using the same, and me Cathode, electron beam emission apparatus using the same, and me

1996-03-04

1998-06-09

Nguyen, Kiet T.

Radiant energy

Inspection of solids or liquids by charged particles

Electron probe type

250423F, 313336, 313346R, H01J 302

Patent

active

057638802

ABSTRACT:
A cathode (e.g., a Schottky emission cathode) having an electron emitter of a tungsten single-crystal with a sharp point, and a heater connected to the electron emitter to heat it. The work function of the crystal face of the point of the electron emitter is reduced by providing adsorbed thereon a nitride of Zr, Ti, Y, Nb, Sc, V or La, or an oxide of Y, Sc, V or La. The nitride or oxide can be formed as a reservoir on the heater (from where it thermally diffuses to the point), or chemically adsorbed on the point. For forming the nitride or oxide on the point, the metal forming the nitride or oxide can be provided on the point and reacted with nitrogen or oxygen thereat to form the nitride or oxide; to provide the metal on the point, the metal forming the nitride or oxide can either be evaporated onto the point, or can form a reservoir on the heater and thermally diffuse therefrom to the point. The effect of reducing the work function results in a cathode having a narrow FWHM (full width at half maximum) of emission electrons and a high current density.

REFERENCES:
patent: 3273005 (1966-09-01), Lafferty
patent: 3814975 (1974-06-01), Wolfe et al.
patent: 4324999 (1982-04-01), Wolfe
patent: 4379250 (1983-04-01), Hosoki et al.
patent: 4438371 (1984-03-01), Hosoki et al.
patent: 5440124 (1995-08-01), Kelly et al.
patent: 5536944 (1996-07-01), Tsunoda et al.
patent: 5616926 (1997-04-01), Shinada et al.
Patent Abstracts of Japan, vol. 018, No. 332, Jun. 23, 1994.

Affiliated with

Also associated with

Rating

Cathode, electron beam emission apparatus using the same, and me does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Cathode, electron beam emission apparatus using the same, and me, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Cathode, electron beam emission apparatus using the same, and me will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2202968