Accession Number:

ADA440247

Title:

Secondary Electron Emission Measurements on Materials Under Stress

Descriptive Note:

Final rept. 16 Sep 2003-23 Jun 2005

Corporate Author:

SAITAMA UNIV URAWA (JAPAN)

Personal Author(s):

Report Date:

2004-10-01

Pagination or Media Count:

99.0

Abstract:

The breakdown of rf windows used in high-power klystron is one of the most serious problems in the development of klystrons. The dielectric breakdown strength of an alumina ceramic surface depends on the secondary electron emission which is influenced by the electronics states of the oxygen vacancy existing adjacent to the ceramic surface. In this report, the durability of several dielectric materials used for rf windows is discussed in terms of secondary of electron emission SEE, cathode luminescence, and dielectric loss. High-power tests of these materials with TiN coating, thus having low SEE, were also carried out using a traveling wave resonant ring. The samples were compared under the conditions of annealing and X-ray irradiation. The influences of annealing and X-ray irradiation on the SEE coefficients and CL spectra were investigated. Energy distributions of secondary electrons under high temperature were analyzed as well. The results show that alumina ceramics are superior to sapphire and aluminum nitride. The original of breakdown was investigated and the requirement for rf window materials presented.

Subject Categories:

  • Electrical and Electronic Equipment
  • Nuclear Physics and Elementary Particle Physics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE