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Off-momentum of a storage ring by offset the RF frequency

Posted: 29 Dec 2021, 20:47
by duanz
Hi Michael and all,

I'm trying to offset the RF frequency of a storage ring and to observe the influence on closed orbit & equilibrium beam parameters. However, in the attached example, Cs in the %s.fin file did show the change of circumference due to the change of RF frequency, while the closed orbit calculation and moments_output results didn't reflect the change. I guess something is not set correctly in my script, but have not idea so far. Your help would be highly appreciated!

Wish you a happy new year!


Zhe

Re: Off-momentum of a storage ring by offset the RF frequency

Posted: 07 Jan 2022, 15:38
by michael_borland
Zhe,

elegant does the closed orbit computations in 4 d, so the effect of rf frequency on the average beam momentum won't be seen.

You can include momentum offset manually using a MALIGN element at the start of the beamline. The DP parameter is used to assert a momentum error, which can be related to the frequency offset using the momentum compaction factor.

--Michael