What is the meaning of Zgen in the plt file?

[foshea]

Hi All,

I'm pulling the particle coordinates out of the .plt file of a simulation that I optimize and run with space charge both on and off (by setting the current to zero). When I do this I find that the value of 'Zgen' is different between the two runs. I had assumed that 'Zgen' is the z-location of the synchronous particle, but doesn't appear to the case and I can't find its description anywhere in the manual. The word itself only shows up twice in the manual in the description of the .plt file contents. The word 'generator' only show up 4 time, 3 of which are irrelevant here and the 4th is on page 161 in the description of conversions between different longitudinal spaces.

What is Zgen and, if it isn't the location of the bunch along the beam line, how do I get that from the .plt file?

[Didier]

Hi,

Normally as you suppose, zgen is the z-position of the synchronous particle. I have reverified this point with and without space charge in simple cases and I confirm it well. Could you post your example showing an error on this point?

Regards,

Didier