Fractional momentum spread sigma_dp

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Repetto
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Joined: 20 Apr 2023, 10:27

Fractional momentum spread sigma_dp

Post by Repetto » 20 Apr 2023, 11:08

Hello,
I am simulating a bunched beam with sigma_dp = 0.001, but respect to my data it's not the same.
In fact, I would like to have an asymmetric sigma_dp (an asymmetry on the left side of my gaussian simulation) to have a better agreement with my data.
Is it possible? If yes, how can I modify my elegant file?
Thank you in advance,
Silvia

michael_borland
Posts: 1927
Joined: 19 May 2008, 09:33
Location: Argonne National Laboratory
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Re: Fractional momentum spread sigma_dp

Post by michael_borland » 02 Jun 2023, 09:48

Silvia,

You can use the program sddssampledist to generate an arbitrary momentum distribution outside of elegant, then load the particles via the sdds_beam command.

Let's assume that your beam is gaussian in (x, xp, y, yp, t), but has a different distribution in momentum. The procedure to generate this beam would be
  1. Run elegant to make a nominal distribution of particles.
  2. Throw out the unwanted p coordinates.
  3. Generate new p coordinates by sampling a desired distribution (sddssampledist).
  4. Merge with other coordinates.
The attached archive has a concrete example.

--Michael
Attachments
customLongitudinal.zip
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michael_borland
Posts: 1927
Joined: 19 May 2008, 09:33
Location: Argonne National Laboratory
Contact:

Re: Fractional momentum spread sigma_dp

Post by michael_borland » 02 Jun 2023, 09:50

Silvia,

There are also several examples in the the elegant examples file, under customBeamDistributions.

--Michael

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