Longitudinal phase-space curvature

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Björklund
Posts: 84
Joined: 19 May 2016, 07:14

Longitudinal phase-space curvature

Post by Björklund » 19 Feb 2019, 08:41

Hi,

I am looking at generating beams inside Elegant for test purposes. I want them to have a chirp, and I also want to be able to set specific curvatures, e.g. from the RF voltage, for a beam going into a compressor. I really can't figure out how to do this, and to me, it looks like it is not possible. I can't get my own script to produce proper transverse phase spaces, so it would be nice to be able to do it directly in Elegant.

Any help is appreciated
Best regards
Jonas

michael_borland
Posts: 1927
Joined: 19 May 2008, 09:33
Location: Argonne National Laboratory
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Re: Longitudinal phase-space curvature

Post by michael_borland » 25 Feb 2019, 13:35

Jonas,

My suggestion is to use elegant's bunched_beam command to generate the transverse phase space you want with some nominal longitudinal phase space, then modify the longitudinal coordinates to suit your needs. There are a few options here
  • Use a thin RFCA element to manipulate the longitudinal coordinates. You can adjust the voltage, phase, and frequency to affect chirp and curvature.
  • Use a SCRIPT element to manipulate or replace the longitudinal coordinates.
  • Generate the longitudinal coordinates separately and replace those elegant generates using sddsconvert (to delete t, p) and sddsxref (to import new values).
In the first two cases, you can set up the manipulations as part of a full run. In the second case, you'd save the coordinates to a file (bunched_beam allows this), modify them, then use sdds_beam to load them in subsequent runs.

--Michael

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