 |
John's Project Page - RISE summer 2003 |
 |
Intern: John Welsh, Dartmouth College
Mentor: Michael Sushchikh
Faculty Supervisor: Eric McFarland
Department: Chemical Engineering |
AN ATOMIC HYDROGEN SOURCE FOR USE IN AN ULTRAHIGH VACUUM
An atomic hydrogen source was constructed, tested, and characterized under
ultrahigh vacuum (UHV) conditions and is available for use in the study of
surface reactions. The atomic hydrogen radical is a key intermediate of many
important industrial reactions and, therefore, an atomic hydrogen source aids
in the study of these reaction mechanisms. Under normal atmospheric conditions,
the atomic hydrogen radical is extremely reactive and difficult to study.
Hence, the use of an atomic hydrogen source in characterizing reaction
mechanisms requires UHV conditions. A vacuum chamber was assembled, and an
ultimate vacuum pressure of 10-10 Torr was achieved. The hydrogen source
functions by thermally cracking molecular hydrogen within the UHV chamber.
The thermal cracking is achieved by electron beam heating on a tungsten
surface. The design of custom control electronics was necessary in order to
heat the tungsten appropriately.
Return to the RISE 2003 project list
