sdds file in CWIGGLER

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Samira.kasaei
Posts: 26
Joined: 15 Jun 2021, 13:38

sdds file in CWIGGLER

Post by Samira.kasaei » 27 Jun 2021, 04:01

Hi,

I wanted to insert a wiggler in a ring. Iused CWIGGLER but I didn't know how to create an sdds file containing harmonic amplitudes. Can you give me some hints?

Many thanks for your help,
Samira

michael_borland
Posts: 1927
Joined: 19 May 2008, 09:33
Location: Argonne National Laboratory
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Re: sdds file in CWIGGLER

Post by michael_borland » 15 Jul 2021, 13:54

Samira,

Perhaps this paper will help explain the ideas
http://accelconf.web.cern.ch/PAC2013/papers/wepsm12.pdf

Also, I've attached a sample file for an APS undulator with a 28-mm period.

--Michael
Attachments
U28-8.5mm-ByHarmonics.sdds
(11.18 KiB) Downloaded 96 times

Samira.kasaei
Posts: 26
Joined: 15 Jun 2021, 13:38

Re: sdds file in CWIGGLER

Post by Samira.kasaei » 25 Aug 2021, 04:45

Dear Michael,
Many thanks for your kind reply.
I insert two wiggler in my lattice and I tried to do optimization. But still I have beta beating.
Could you please to take a look to my files?
FYI:First I run nominal.ele and I get twiss parameters. Then I run optimize.ele and I get optimize.new. Finally I run track.ele

Cheers,
Samira
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file.tar.gz
(11.47 KiB) Downloaded 81 times

michael_borland
Posts: 1927
Joined: 19 May 2008, 09:33
Location: Argonne National Laboratory
Contact:

Re: sdds file in CWIGGLER

Post by michael_borland » 26 Aug 2021, 13:22

Samira,

The problem is that setting alpha=eta'=0 at the ends of two sectors doesn't ensure that the lattice functions are symmetric. Further, I don't think you have enough independent quadrupoles to fix the beats.

I've attached a modified version of your files that shows how you could solve the problem. It's possible I introduced too many independent quadrupoles, but it gives you the idea.

--Michael
Attachments
example.tar.gz
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