Bombardment of vacuum chamber walls by an electron gun within the chamber achieves greater efficiency with less cost. The ultimate vacuum reached using the gun is greater than the system design level

Przybyszewski, J.

Swiker, M. A.

Watson, J.

English

NASA Technical Reports Server

September 1965
	
Brief 65-10280 
NASA TECH BRIEF 
NASA Tech Briefs are issued by the Technology Utilization Division to summarize specific 
technical innovations derived from the space program. Copies are available to the public from 
the Clearinghouse for Federal Scientific and Technical Information, Springfield, Virginia, 22151. 
Electron Bombardment Improves Vacuum Chamber Efficiency 
The problem: To achieve greater efficiency in 
vacuum chambers without the costly and/or time 
consuming use of bake-out or cryogenic pumping 
methods. 
The solution: Bombardment of the vacuum 
chamber walls by an electron gun placed within 
the chamber. 
How it's done: A system designed to test certain 
lubricants in a high vacuum environment was 
equipped with an electron gun to bombard the test 
specimens with a 40 Ke y electron beam. The purpose 
of this beam was the removal of contaminants 
adsorbed on the surface of the test specimens. As a 
result of turning on this electron gun for short 
periods, better vacuums resulted. Apparently 
adsorbed layers of gas vapor were being released from 
the chamber walls by a scrubbing action resulting 
from electron bombardment. The source of these 
electrons were those either missing or being reflected 
from the test specimen. Further experiments were 
made to verify this finding and resulted in vacuum
increases from 10-8 mm Hg to 1010 mm Hg occurring 
in a relatively short time. 
Notes: 
1. By the use of the electron gun within the test 
chamber, in conjunction with the standard vacuum 
pump-down system, an ultimate pressure of 10-13 
mm Hg was reached as contrasted to the system 
barely reaching its design level of 10 10 mm Hg 
without the benefit of the electron gun. 
2. Inquiries concerning this innovation may be 
directed to: 
Technology Utilization Officer 
Lewis Research Center 
21000 Brookpark Road 
Cleveland, Ohio 44135 
Reference: B65-10280 
Patent status: NASA encourages commercial use 
of this innovation. No patent action is contemplated 
by NASA. 
Source: Max A.Swiker, John Przybyszewski,
and John Watson
(Lewis- 160) 
Category 02 
This document was prepared under the sponsorship of the National 
Aeronautics and Space Administration. Neither the United States 
Government nor any person acting on behalf of the United States
Government assumes any liability resulting from the use of the 
information contained in this document, or warrants that such use 
will be free from privately owned rights.
https://ntrs.nasa.gov/search.jsp?R=19650000278 2020-03-11T17:20:53+00:00Z


Electron bombardment improves vacuum chamber efficiency

Abstract

Similar works

Full text

Available Versions

NASA Technical Reports Server