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sdds file in CWIGGLER
Posted: 27 Jun 2021, 04:01
by Samira.kasaei
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
Re: sdds file in CWIGGLER
Posted: 15 Jul 2021, 13:54
by michael_borland
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
Re: sdds file in CWIGGLER
Posted: 25 Aug 2021, 04:45
by Samira.kasaei
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
Re: sdds file in CWIGGLER
Posted: 26 Aug 2021, 13:22
by michael_borland
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