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Title: Excitation of the fundamental mode of the coaxial plasma slow-wave structure in a high-current REB Cherenkov plasma amplifier

Journal Article · · Soviet Journal of Plasma Physics
OSTI ID:105381

An experimental study has been carried out of the dispersion properties of a circular waveguide containing a hollow magnetized plasma. Such a plasma configuration can be used as a slow-wave structure in a Cherenkov microwave amplifier driven by a high-current relativistic electron beam. The radius of the external metal container was 1.8 cm, the mean radius of the plasma tube was 0.9 cm, and the thickness of the tube was 0.08 cm. The plasma density varied from 2{center_dot}10{sup 11} to 10{sup 14} cm{sup {minus}3}. The propagation of a monochromatic microwave signal with wavelength {lambda}{sub 0} = 2.42 cm and low power (12 W) through the coaxial plasma-filled waveguide was studied over a wide range of external magnetic field strengths. The threshold values of the magnetic field and plasma density above which the effective excitation and propagation of the basic plasma mode (the slow TM{sub 01} mode) have been found. These values are 0.6 T and 2{center_dot}10{sup 13} cm{sup {minus}3}, respectively. High-power microwave radiation (150 kW) has been transported through a plasma coax of length 30 cm in the regime in which the plasma density and external field strength exceed the threshold values. The experimental results are compared with analytical expressions and a numerical calculation performed for a magnetized plasma-filled waveguide. 11 refs., 6 figs.

OSTI ID:
105381
Journal Information:
Soviet Journal of Plasma Physics, Vol. 18, Issue 7; Other Information: PBD: Jul 1992; TN: Translated from Fiz. Plazmy; 18: No. 7, 857-868(Jul 1992)
Country of Publication:
United States
Language:
English