Comparison of CONDOR, FCI and MAFIA calculations for a 150 MW S-band klystron with measurements

To facilitate the design of high power klystrons an investigation into the reliability and accuracy of three modern particle-in-cell codes was performed. A 150 MW S-band klystron for which measurements were available was used for this comparison. The field calculations of the particle-in-cell codes are based on a finite difference time domain scheme, and use a port approximation to speed up the convergence to steady state. However they differ in many details (e.g. calculation of E, B or A, φ; space charge correction; 2D or 3D modelling of the output cavity)