THALLIUM BEAM TUBE RESEARCH.
Abstract
An investigation of the effect of oxygen on the efficiency of iridium for surface ionization of thallium shows that a layer of oxygen on the iridium surface markedly increased the ionization efficiency, but that the oxygen desorbs quickly at temperatures high enough to evaporate thallium ions in a reasonable time. Further study of cylindrical cavities with a coaxial center section demonstrates that completely suppressed modes nearly degenerate with the desired mode interfere with the tuning and amplitude of the desired mode, making design of a satisfactory cavity difficult. The prototype thallium beam tube was completed, and in preliminary tests performed satisfactorily. The limit on short term stability set by short noise in less than 1 x 10 to the minus 11th power for a one second averaging time at a moderate beam intensity. The line width of the microwave transition is 180Hz, corresponding to an average beam velocity of .25 alpha. The oxygen pressure in operation is less than 10 to the minus 7th power Torr. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- May 01, 1966
- Accession Number
- AD0482823
Entities
People
- Richard F. Lacey