Modified liquid metal cathode apparatus permits vapor feeding in the diffuse-spot pattern mode. Vapor-fed cathode has advantages over liquid-fed systems

Eckhardt, W. O.

English

NASA Technical Reports Server

.D iffus 
Spot 
Patter
Reservoir 
August 1970
	
Brief 70-10168 
NASA Tech Briefs announce new technology derived from the U.S. space program. They are issued to encourage commercial 
application. Tech Briefs are available on a subscription basis from the Clearinghouse for Federal Scientific and Technical 
Information, Springfield, Virginia 22151. Requests for individual copies or questions relating to the Tech Brief program may 
be directed to the Technology Utilization Division, NASA, Code UT, Washington, D.C. 20546. 
Vapor Feeding of Liquid Metal Cathodes 
Liquid Metal Cathode Apparatus Modification 
A liquid metal (LM) cathode apparatus has been 
modified to permit vapor feeding in the diffuse spot-
pattern (DSP) mode. 
The vapor-fed cathode possesses certain advantages 
over liquid-fed systems. These are: 1) higher efficiency 
and lower specific thermal loading should result 
from therniall	 decoupline the pool-keeping true-
ture from the evaporator (the required electron-
to-atom emission ratio may be obtained with less 
vapor flow constriction downstream from the electron-
emitting zone); 2) a vapor-fed LM cathode can use 
the same feed system and isolator as are used for 
electron-bombardment thrusters with other cathode 
t\pes permitting more flexibility in cathode choice; 
onhinued onerleaf) 
AOL 
qW
This document was prepared under the sponsorship of the National	 Government assumes any liability resulting from the use of the 
Aeronautics and Space Administration. Neither the United States 	 information contained in this document, or warrants that such use 
Government nor any person acting on behalf of the United States 	 will be free from privately owned rights.
https://ntrs.nasa.gov/search.jsp?R=19700000162 2020-03-17T00:29:37+00:00Z
3) it may be possible to achieve such high electron-
to-atom emission ratios that only a fraction of the 
total expellant flow needs to be fed through the 
cathode. 
The feed system conversion was accomplished by 
omitting the flow impedance, electron-beam welding 
a stainless-steel vaporizer mesh into the feedline, and 
wrapping a heater around the feedline portion 
between vaporizer and cathode. 
Note: 
The following documentation may be obtained 
from:
Clearinghouse for Federal Scientific 
and Technical Information 
Springfield, Virginia 22151 
Single document price $3.00 
(or microfiche $0.65) 
Reference: 
NASA-CR-93771 (N68-20121), High-
Temperature LM Cathodes for Ion 
Thrusters
Patent status: 
No patent action is contemplated by NASA. 
Source: W. 0. Eckhardt of 
Hughes Aircraft Company 
under contract to 
NASA Headquarters 
(HQN- 102 13) 
Brief 70-10168	 Category 03


Vapor feeding of liquid metal cathodes

Abstract

Similar works

Full text

Available Versions

NASA Technical Reports Server