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

Patent · Sun Jan 01 00:00:00 EST 1989

OSTI ID:866811

Leung, Ka-Ngo ^[1]; Gordon, Keith C ^[2]; Kippenham, Dean O ^[3]; Purgalis, Peter ^[4]; Moussa, David ^[4]; Williams, Malcom D ^[5]; Wilde, Stephen B ^[6]; West, Mark W ^[7]

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1. Hercules, CA
2. Berkeley, CA
3. Castro Valley, CA
4. San Francisco, CA
5. Danville, CA
6. Pleasant Hill, CA
7. Albany, 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 urged against an outer peripheral contact surface (24) of the head end (21) to provide a mechanical and electrical connection to the cathode element (11).

• Research Organization: Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)
• DOE Contract Number: AC03-87SF00098
• Assignee: United States of America as represented by United States (Washington, DC)
• Patent Number(s): US 4795940
• OSTI ID: 866811
• Country of Publication: United States
• Language: English

Related Subjects

directly
heated
lanthanum
hexaboride
cathode
structure
predetermined
emission
profile
lab
10
disclosed
comprises
element
11
circular
shape
central
axis
head
21
upper
substantially
planar
surface
23
downwardly
intermediate
portion
26
diminishes
cross-section
towards
base
22
rod
14
connected
extends
plural
upstanding
spring
fingers
37
urged
outer
peripheral
contact
24
provide
mechanical
electrical
connection
substantially planar
cathode structure
cathode element
contact surface
central axis
electrical connection
lanthanum hexaboride
outer peripheral
central rod
directly heated
heated lanthanum
hexaboride cathode
boride cathode
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