skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Scaling experiments on a magnetically insulated thermionic vacuum switch

Book ·
OSTI ID:63095
;  [1]
  1. Royal Inst. of Technology, Stockholm (Sweden). Dept. of Industrial Electrotechnology

Magnetic insulation of the electron flow in a cylindrical thermionic vacuum diode has been proposed as a way to achieve a fast high-voltage high-power opening switch. The expected performance of this type of device can be derived from a set of basic scaling laws combined with empirical relationships obtained from experimental studies. Switch losses are mainly due to anode dissipation W{sub a}, which can be normalized to the transferred pulse energy. Leakage current and switch hold-off voltage depend on device geometry, materials, vacuum conditions etc and must be determined experimentally. For this purpose, the MX-1 experiment has been designed and operated. This device is basically a smooth-bore cylindrical magnetron with a 5 cm radius, 400 cm{sup 2} area thermionic dispenser cathode separated from the coaxial water-cooled anode by a few mm wide gap. This design allows pulsed operation at up to {approximately}100 kV, {approximately}4 kA and average power levels of {approximately}1 MW. The MX-1 switch is used as an opening switch to produce 1--2 {mu}s long square pulses from an inductive storage PFN. The current-voltage characteristics of the switch are determined as a function of the applied magnetic field and load condition. Plasma wave measurements are performed to investigate the stability of the electron flow. Results are summarized in the form of scaling diagrams for the important switch parameters, showing possible performance levels and physical and technical limitations identified as far in this work.

OSTI ID:
63095
Report Number(s):
CONF-940604-; ISBN 0-7803-2006-9; TRN: IM9527%%146
Resource Relation:
Conference: 1994 Institute of Electrical and Electronic Engineers (IEEE) international conference on plasma science, Santa Fe, NM (United States), 6-8 Jun 1994; Other Information: PBD: 1994; Related Information: Is Part Of 1994 IEEE international conference on plasma science; PB: 252 p.
Country of Publication:
United States
Language:
English