Field free, directly heated lanthanum boride cathode

Patent · Tue Jan 01 04:00:00 EST 1991

OSTI ID:867715

Leung, Ka-Ngo ^[1]; Moussa, David ^[2]; Wilde, Stephen B ^[3]

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1. Hercules, CA
2. San Francisco, CA
3. Pleasant Hill, CA

A directly heated cylindrical lanthanum boride cathode assembly is disclosed which minimizes generation of magnetic fields 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 opposite magnetic field generated by current flowing through the lanthanum boride cylinder and the coaxial electrode in a direction opposite to the current flow in the central shaft.

• Research Organization: Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA
• Assignee: United States of America as represented by United States (Washington, DC)
• Patent Number(s): US 4994706
• OSTI ID: 867715
• Country of Publication: United States
• Language: English

Related Subjects

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assembly
assembly comprises
boride
boride cathode
cancelled
carry
cathode
cathode assembly
central
central shaft
central support
coaxial
coaxial electrode
coaxially
coaxially position
comprises
contact
current
current flow
current flowing
cylinder
cylindrical
direction
direction opposite
directly
directly heated
disclosed
electrical
electrical contact
electrode
electron
electron emission
emission
field
field free
field generated
fields
fields generated
flow
flowing
free
functions
generated
generation
heated
heated lanthanum
heater
interfere
lanthanum
lanthanum boride
magnetic
magnetic field
magnetic fields
minimizes
opposite
position
shaft
support
support shaft