RFTMEZ0 and not-so-relativistic beam capture

[broemmel]

Hi Michael,

I used bead pull data to create an on-axis field map for use in a RFTMEZ0 element. I found that for an initial low momentum beam, there was no appreciable acceleration. I split the field map into cells, put them all on the same PHASE_REFERENCE, then adjusted PHASE in the first cell and TIME_OFFSET in the last two cells to account for the initial not-so-relativistic beam. On the second pass, EZ_PEAK is successfully optimized to give the final beam energy.

Is there a better, more correct, way to account for the capture and acceleration of the first cell when using the RFTMEZ0 element? I did this according to my understanding of RFTMEZ0 items, which is probably incomplete.

Thanks, Dan