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

Patent · Sat Dec 31 23:00:00 EST 1988

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
• 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

/313/
10
11
14
21
22
23
24
26
37
axis
base
boride cathode
cathode
cathode element
cathode structure
central
central axis
central rod
circular
comprises
connected
connection
contact
contact surface
cross-section
diminishes
directly
directly heated
disclosed
downwardly
electrical
electrical connection
element
emission
extends
fingers
head
heated
heated lanthanum
hexaboride
hexaboride cathode
intermediate
lab
lanthanum
lanthanum hexaboride
mechanical
outer
outer peripheral
peripheral
planar
plural
portion
predetermined
profile
provide
rod
shape
spring
structure
substantially
substantially planar
surface
towards
upper
upstanding
urged