COLLECT3D code for accurate multistage collector simulation

The computer code COLLECT3D was written in 1998 in order to get a realistic and efficient modeling tool for multistage collector design improvement. This is a time dependent PIC code representing the beam in macro-particles and taking into account the 3D geometry, the 3D magnetic field distribution and the secondary or reflected electron emission. It is now intensively used at T.E.D. for efficiency optimization purpose in combination with the new 2.5D interaction codes (MVTRAD for helix TWTs and KLYS 2D for klystrons) which use the same beam modeling. The simulation results obtained from these new tools are very close to measured test data and open the way for further efficiency improvements on space TWTs and telecom tubes. They are also very useful to optimize klystron designs to get high efficiency without reflected electrons.