Two‐dimensional features of virtual cathode and microwave emission

A two‐dimensional model for the electron flow in the presence of a virtual cathode is presented. The model allows for electron reflexing and velocity distribution spread. Solutions with substantial radial flow agree closely with high‐power microwave emission observed in experiments. The radial motion is the result of the self‐magnetic field of the beam, which bends some of the electrons from propagating to side walls to reflex between real and virtual cathodes. The resulting plasma frequency solution agrees with the measured microwave frequency, which scales linearly with the diode current instead of the square‐root scaling for a one‐dimensional flow. Scaling laws are derived and agree with experimental measurements.

[1]  J. Benford,et al.  Dynamics of a virtual cathode oscillator driven by a pinched diode , 1986 .

[2]  Woo,et al.  Virtual-cathode oscillator emission by a pinched diode. , 1986, Physical review letters.

[3]  J. Benford,et al.  A Radially and Axially Extracted Virtual-Cathode Oscillator (Vircator) , 1985, IEEE Transactions on Plasma Science.

[4]  Bartsch,et al.  High-power microwave generation from a virtual cathode device. , 1985, Physical review letters.

[5]  S. C. Burkhart,et al.  A virtual‐cathode reflex triode for high‐power microwave generation , 1985 .

[6]  H. Helava,et al.  The reflex switch: A new vacuum opening switch for use with magnetic energy storge , 1985 .

[7]  Thomas J. T. Kwan,et al.  High‐power coherent microwave generation from oscillating virtual cathodes , 1984 .

[8]  E. Coutsias,et al.  Space-charge-limit instabilities in electron beams , 1983 .

[9]  R. Miller,et al.  An Introduction to the Physics of Intense Charged Particle Beams , 1982 .

[10]  Jeffry Golden,et al.  High-power microwaves from a non-isochronous reflecting electron system (NIRES) , 1977 .

[11]  I. D. Smith,et al.  Multiple reflections of electrons and the possibility of intense positive‐ion flow in high ν/γ diodes , 1975 .

[12]  I. D. Smith,et al.  Method of Generating Very Intense Positive-Ion Beams , 1975 .

[13]  John M. Creedon,et al.  Relativistic Brillouin flow in the high ν/γ diode , 1975 .

[14]  R. Davidson,et al.  Focused-flow model of relativistic diodes , 1974 .

[15]  C. Birdsall,et al.  Electron dynamics of diode regions , 1966 .