Large Increase Of Bunch Length Ss After Transversing RFCA

[Zamank]

Hi All,

I have a curious issue for a very large (~2x) Ss increase after I track through the FIRST RFCA "L2CELL12" in my beamline located at "s=3.702961e+00" . I am trying to account for the Ss increase analytically but I am having trouble. What could be an explanation?

Thank you in advance!

I have attached the relevant files.

[michael_borland]

The problem is that Ss is not the bunch length, but the rms equivalent path length, where "equivalent path length" is the distance a particle would have to travel at its present velocity in order to end up at the given location at a given time. When the particle velocity changes a lot (e.g., initial acceleration from low energy), the equivalent path length must also change. You should look at St instead of Ss if you are interested in the physical bunch duration.

More discussion is available in the manual.

--Michael