Large area directly heated lanthanum hexaboride cathode structure having predetermined emission profile

Title: Large area directly heated lanthanum hexaboride cathode structure having predetermined emission profile

Full Record
Other Related Research

Abstract

A large area directly heated lanthanum hexaboride (LaB/sub 6/) cathode system is disclosed. The system comprises a LaB/sub 6/ cathode element generally circular in shape about a central axis. The cathode element has a head with an upper substantially planar emission surface, and a lower downwardly and an intermediate body portion which diminishes in cross-section from the head towards the base of the cathode element. A central rod is connected to the base of the cathode element and extends along the central axis. Plural upstanding spring fingers are urged against an outer peripheral contact surface of the head end to provide a mechanical and electrical connection to the cathode element. 7 figs

Inventors:: Leung, Ka-Ngo; Gordon, K C; Kippenhan, D O; Purgalis, P; Moussa, D; Williams, M D; Wilde, S B; West, M W

Issue Date:: 1987-10-16

Research Org.:: Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

OSTI Identifier:: 6682795

Patent Number(s):: 6108327

Application Number:: ON: DE89000184

Assignee:: LBNL; ERA-14-003724; EDB-88-195598

Patent Classifications (CPCs):: H - ELECTRICITY H04 - ELECTRIC COMMUNICATION TECHNIQUE H04B - TRANSMISSION

Show more

H - ELECTRICITY H04 - ELECTRIC COMMUNICATION TECHNIQUE H04B - TRANSMISSION
H04B1/7085 - using a code tracking loop, e.g. a delay-locked loop

Show less

DOE Contract Number:: AC03-76SF00098

Resource Type:: Patent

Resource Relation:: Other Information: Portions of this document are illegible in microfiche products

Country of Publication:: United States

Language:: English

Subject:: 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; 36 MATERIALS SCIENCE; CATHODES; DESIGN; LANTHANUM BORIDES; SURFACE AREA; CHEMICAL PROPERTIES; ELECTRON EMISSION; INVENTIONS; PHYSICAL PROPERTIES; THERMIONIC EMITTERS; BORIDES; BORON COMPOUNDS; ELECTRODES; EMISSION; LANTHANUM COMPOUNDS; RARE EARTH COMPOUNDS; SURFACE PROPERTIES; 640301* - Atomic, Molecular & Chemical Physics- Beams & their Reactions; 360204 - Ceramics, Cermets, & Refractories- Physical Properties

Citation Formats


                    Leung, Ka-Ngo, Gordon, K C, Kippenhan, D O, Purgalis, P, Moussa, D, Williams, M D, Wilde, S B, and West, M W. Large area directly heated lanthanum hexaboride cathode structure having predetermined emission profile.  United States: N. p., 1987. 
        Web.

Copy to clipboard


                    Leung, Ka-Ngo, Gordon, K C, Kippenhan, D O, Purgalis, P, Moussa, D, Williams, M D, Wilde, S B, & West, M W. Large area directly heated lanthanum hexaboride cathode structure having predetermined emission profile.  United States.

Copy to clipboard


                    Leung, Ka-Ngo, Gordon, K C, Kippenhan, D O, Purgalis, P, Moussa, D, Williams, M D, Wilde, S B, and West, M W. Fri .  
        "Large area directly heated lanthanum hexaboride cathode structure having predetermined emission profile".  United States.

Copy to clipboard


                    
@article{osti_6682795,

  title        = {Large area directly heated lanthanum hexaboride cathode structure having predetermined emission profile},

  author       = {Leung, Ka-Ngo and Gordon, K C and Kippenhan, D O and Purgalis, P and Moussa, D and Williams, M D and Wilde, S B and West, M W},

  abstractNote = {A large area directly heated lanthanum hexaboride (LaB/sub 6/) cathode system is disclosed. The system comprises a LaB/sub 6/ cathode element generally circular in shape about a central axis. The cathode element has a head with an upper substantially planar emission surface, and a lower downwardly and an intermediate body portion which diminishes in cross-section from the head towards the base of the cathode element. A central rod is connected to the base of the cathode element and extends along the central axis. Plural upstanding spring fingers are urged against an outer peripheral contact surface of the head end to provide a mechanical and electrical connection to the cathode element. 7 figs},

  doi          = {},

  journal      = {},
number       = ,

  volume       = ,

  place        = {United States},

  year         = {1987},

  month        = {10}

}

Copy to clipboard

Patent:

Search for the full text at the U.S. Patent and Trademark Office

Save / Share:

Export Metadata

Save to My Library

Similar Records in DOE Patents and OSTI.GOV collections:

Large area directly heated lanthanum hexaboride cathode structure having predetermined emission profile

Patent Leung, Ka-Ngo [Hercules, CA]; Gordon, Keith C [Berkeley, CA]; Kippenham, Dean O [Castro Valley, CA]; ...

A large area directly heated lanthanum hexaboride (LaB.sub.6) cathode system (10) is disclosed. The system comprises a LaB.sub.6 cathode element (11) generally circular in shape about a central axis. The cathode element (11) has a head (21) with an upper substantially planar emission surface (23), and a lower downwardly and an intermediate body portion (26) which diminishes in cross-section from the head (21) towards the base (22) of the cathode element (11). A central rod (14) is connected to the base (22) of the cathode element (11) and extends along the central axis. Plural upstanding spring fingers (37) are urgedmore »« less
Full Text Available
Directly heated lanthanum hexaboride cathode

Journal Article Leung, K N; Moussa, D; Wilde, S B - Rev. Sci. Instrum.; (United States)

A directly heated, cylindrical LaB/sub 6/ cathode has been tested in a multicusp plasma generator. Magnetic fields generated by the heater and the discharge current are minimized by the special coaxial construction, thus enabling electron emission at very low discharge voltages. At higher discharge voltage, a discharge current greater than 100 A has been obtained from a single cathode unit in a steady-state plasma source operation. When the discharge current exceeds 25 A, the cathode can be operated without any heater current. The emission temperature is maintained just by ion bombardment from the discharge plasma.
DOI: https://doi.org/10.1063/1.1138641
Field free, directly heated lanthanum boride cathode

Patent Leung, Ka-Ngo; Moussa, D; Wilde, S B

A directly heated cylindrical lanthanum boride cathode assembly is disclosed which minimizes generation of magnetic field which would interfere with electron emission from the cathode. The cathode assembly comprises a lanthanum boride cylinder in electrical contact at one end with a central support shaft which functions as one electrode to carry current to the lanthanum boride cylinder and in electrical contact, at its opposite end with a second electrode which is coaxially position around the central support shaft so that magnetic fields generated by heater current flowing in one direction through the central support shaft are cancelled by an oppositemore »« less
Directly heated lanthanum hexaboride filaments

Journal Article Leung, K N; Pincosy, P A; Ehlers, K W - Rev. Sci. Instrum.; (United States)

Some physical properties of lanthanum hexaboride filaments, when operated as cathodes in a gas discharge, are presented. These directly heated hairpin-shaped filaments have been tested in different types of ion sources and are shown to be capable of long-pulse or cw discharge operations. The design of a shaped lanthanum hexaboride filament for the purpose of further extension of lifetime is also described.
DOI: https://doi.org/10.1063/1.1137902
Large-area lanthanum hexaboride electron emitter

Journal Article Goebel, D M; Hirooka, Y; Sketchley, T A - Rev. Sci. Instrum.; (United States)

A large-area cathode assembly which is capable of continuous, high-current electron emission is described. The cathode utilizes an indirectly heated lanthanum hexaboride (LaB/sub 6/) disk as the thermionic electron emitter. The LaB/sub 6/ cathode emits over 600 A of electrons at an average of 20 A/cm/sup 2/ continuously with no observable lifetime limits to date after about 400 h of operation in a plasma discharge. Proper clasping of the LaB/sub 6/ disk is required to avoid impurity production from chemical reactions with the holder and to provide adequate support if the disk fractures during rapid thermal cycling. Modification of themore »« less
DOI: https://doi.org/10.1063/1.1138130

Similar Records