Mode competition, suppression, and efficiency enhancement in overmoded gyrotron oscillators

Y. Carmel, K. R. Chu, D. Dialetis, A. Fliflet, M. E. Read, K. J. Kim, B. Arfin, V. L. Granatstein

Research output: Contribution to journalArticlepeer-review


Gyrotron oscillators are of great interest as sources of high power mm wave radiation for electron cyclotron resonance heating and current drive in magnetic fusion research devices. Gyrotrons capable of efficiently generating cw power ≳ 1 megawatt will be required in future magnetic fusion studies. However, as gyrotron power approaches the megawatt level, a very large, overmoded cavity must be employed in order to keep ohmic power losses in the cavity at an acceptable level, and the problem of mode overpopulation becomes severe. Also, it becomes increasingly important to optimize gyrotron efficiency for a number of important reasons including minimizing the problem of collecting the electron beam energy. In the present paper, a detailed experimental and theoretical study of mode competition and mode locking in an overmoded gyrotron is presented. Efficiency enhancement (to 60%) and high peak power (430 kW) were achieved in the TE2,4,1 mode using magnetostatic profiling in the cavity. With selective mode suppression, peak power of 475 kW was generated in the TE0,4,1 mode.

Original languageEnglish (US)
Pages (from-to)645-665
Number of pages21
JournalInternational Journal of Infrared and Millimeter Waves
Issue number5
StatePublished - Sep 1982
Externally publishedYes

ASJC Scopus subject areas

  • Radiation
  • Atomic and Molecular Physics, and Optics
  • Instrumentation
  • Condensed Matter Physics
  • Physics and Astronomy (miscellaneous)
  • Electrical and Electronic Engineering


Dive into the research topics of 'Mode competition, suppression, and efficiency enhancement in overmoded gyrotron oscillators'. Together they form a unique fingerprint.

Cite this