frequency map

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Samira.kasaei
Posts: 41
Joined: 15 Jun 2021, 13:38

frequency map

Post by Samira.kasaei » 23 Sep 2026, 02:16

Dear Michael,

I am calculating frequency map for my lattice. I added the frequency map calculated by AT, that shows discrepancy between AT and elegant. I increased the n_passes or n_kicks in my lattice but I didn't get better results.
And Could please let me how I can plot the tune frequency map with integer numbers included(7.23,6.19 in my case like the AT one)? :idea:

Many thanks in advance for your helpful comments,

Samira
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michael_borland
Posts: 2068
Joined: 19 May 2008, 09:33
Location: Argonne National Laboratory
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Re: frequency map

Post by michael_borland » 23 Sep 2026, 10:14

Samira,

You can offset the x and y axes values by the integer tunes using the -offset option in sddsplot, e.g.,

Code: Select all

sddsplot -col=nux,nuy fma_1.fma -graph=sym,vary=subtype,fill -split=col=diffusionRate  -order=spect -offset=xch=7,ych=6 -scale=7.2,7.28,6,6.4
Looking at your lattice file, I noticed that you included an RF cavity, which isn't recommended for FMA. Also, the CSBEND element is not using sufficient number of slices for good results; see attached for recommended settings. Finally, the chromaticities are both negative.

--Michael
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Samira.kasaei
Posts: 41
Joined: 15 Jun 2021, 13:38

Re: frequency map

Post by Samira.kasaei » 13 Oct 2026, 02:22

Dear Michael,

Thank you for your reply.
I tried the new lattice however i didnt get a closer result to AT :( .
I do appreciate if you have any other comment in this topic.

Many thanks and best regards,
Samira

michael_borland
Posts: 2068
Joined: 19 May 2008, 09:33
Location: Argonne National Laboratory
Contact:

Re: frequency map

Post by michael_borland » 13 Oct 2026, 10:24

Samira,

I'm not sure what the issue might be. We compared elegant and AT in the past for nonlinear dynamics and found good agreement. See
this paper.

--Michael

koryun
Posts: 2
Joined: 19 Aug 2010, 11:56

Re: frequency map

Post by koryun » 05 Nov 2026, 07:04

Daer Samira,

Sorry for jumping in, but looking at my old AT lattice for SESAME, I noticed that the sextupole strengths have the same numerical values as those in your elegant lattice. However, the multipole-strength definitions in AT and elegant are different, so you need to multiply the sextupole strengths from AT by a factor of 2 when converting them to elegant.

Koryun

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