Simulation of Klystrons With Slow and Reflected Electrons Using Large-Signal Code TESLA

The problem of modeling slow and reflected electrons that appear during operation of high-power klystrons is discussed. These electrons are not only problematic for the operation of real klystrons but also present a numerical challenge for simulation codes that solve the equations of motion with axial distance rather than time as the independent parameter. To meet this challenge, particles with axial velocity below some threshold are treated using an alternative algorithm. This approach has been implemented in the simulation code TESLA. The method is verified by comparison with PIC simulation. The effect of these particles on the efficiency of a hypothetical device is also presented.

[1]  Robert J. Barker,et al.  Modern Microwave and Millimeter-Wave Power Electronics , 2005 .

[2]  S. Fukuda,et al.  INSTABILITY CAUSED BY BACKSTREAMING ELECTRONS IN KLYSTRON , 2001 .

[3]  T. Antonsen,et al.  High-power four-cavity S-band multiple-beam klystron design , 2004, IEEE Transactions on Plasma Science.

[4]  B. Levush,et al.  Demonstration of an S-band, 600-kW fundamental-mode multiple-beam klystron , 2005, IEEE Electron Device Letters.

[5]  T. Antonsen,et al.  Simulation of microwave devices with external cavities using MAGY , 2002, Third IEEE International Vacuum Electronics Conference (IEEE Cat. No.02EX524).

[6]  T. Antonsen,et al.  Validation of the large-signal klystron Simulation code TESLA , 2004, IEEE Transactions on Plasma Science.

[7]  W. Roybal,et al.  Dynamics of Retrograde Electrons Returning From the Output Cavity in Klystrons , 2006, IEEE Transactions on Electron Devices.

[8]  David R. Smith,et al.  User-configurable MAGIC for electromagnetic PIC calculations , 1995 .

[9]  B. Goplen,et al.  Analysis of the 425-MHz Klystrode , 1991 .

[10]  B. Levush,et al.  Large-Signal Code TESLA: Improvements in the Implementation and in the Model , 2006, 2006 IEEE International Vacuum Electronics Conference held Jointly with 2006 IEEE International Vacuum Electron Sources.