Elegant users forum

Hi

According to page 9 of the ELEGANT Manual, I can load the bunched beam only from an external file using sdds_beam. An external file for a single bunch is to be generated by bunched_beam in a separate run. Why is this true?
Can I just use the bunched_beam to generae a bunch in an input file and set pass number in run_control to load the bunched beam into the beamline?
I tried it and it worked without having to use a separate run and sdds_beam. Maybe I did not understand true meaning of what is written in the manual. Could you explain to me?

Best,

If you want to track a multi-bunch beam in a ring with long-range collective effects (e.g., using *RFMODE, LRWAKE), then you need to create the beam separately and load it using sdds_beam.

If you just want to track one bunch after the next with no collective interaction, you can use the n_steps parameter in run_control to do that. An exception is if you want to track a single-pass system, such as a linac. In that case, you can use n_steps to send one bunch at a time into the system. However, to include long-range collective effects, you must set RESET_FOR_EACH_STEP=0 on any *RFMODE elements.

If this doesn't clarify the problem, please tell me more about what you are trying to simulate.

--Michael