The influence of desorption gas to high power microwave window multipactor
- Department of Engineering Physics, Tsinghua University, Beijing 100084 (China)
- Northwest Institute of Nuclear Technology, Xi'an, Shannxi 710024 (China)
Gas desorbed by electrons plays a key role in multipactor saturation and final plasma breakdown at the vacuum side of the window in high power microwave systems. A multipactor model involving electron-neutral collision and ionization is established. When desorption gas pressure reaches 1 Torr, the electron impact energy apparently decreases, multipactor saturates at a lower surface charging field, and multipactor saturation meets easier, compared to vacuum. Experiments for different material windows of high power microwave, with the power of 1 GW, frequency of 9.4 GHz, and 20 ns single and multiple pulses was conducted. It was discovered that gas pressure rose prominently in the horn, when breakdown occurred. The increase in local gas pressure during the 20 ns pulse is estimated from the experiment to reach several Torr, a pressure that is consistent with the presented dynamic model.
- OSTI ID:
- 21269078
- Journal Information:
- Physics of Plasmas, Vol. 15, Issue 9; Other Information: DOI: 10.1063/1.2977988; (c) 2008 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 1070-664X
- Country of Publication:
- United States
- Language:
- English
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