How to scan Twiss Parameter?
Moderators: cyao, michael_borland
How to scan Twiss Parameter?
Hi Guys,
I am wondering how would I go about scanning various values of the twiss functions. In particular, I have a beamline with a 4-chicane bunch compressor somewhere in the middle, I was wondering how would I go about ONLY changing betax at the entrance of the BC (or only changing the alphax, or any of the twiss parameters really).
I tried parameter vary, but couldn't get it to work (probably not the right process anyway).
As always, thanks for the help!
I am wondering how would I go about scanning various values of the twiss functions. In particular, I have a beamline with a 4-chicane bunch compressor somewhere in the middle, I was wondering how would I go about ONLY changing betax at the entrance of the BC (or only changing the alphax, or any of the twiss parameters really).
I tried parameter vary, but couldn't get it to work (probably not the right process anyway).
As always, thanks for the help!
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Re: How to scan Twiss Parameter?
You can do this by inserting a TWISS element at the start of the beamline, then varying the parameters of that element.
--Michael
--Michael
Re: How to scan Twiss Parameter?
Perfect, got it working...awesome thank you
!
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Re: How to scan Twiss Parameter?
Hi Michael,
I was wondering if there was a way to do a scan for PSIX (the phase advance)? I am currently using a input matrix file to do this, but the sddscollapse and .finc method that you use is so much cleaner.
Thanks in advance!
I was wondering if there was a way to do a scan for PSIX (the phase advance)? I am currently using a input matrix file to do this, but the sddscollapse and .finc method that you use is so much cleaner.
Thanks in advance!
-
- Posts: 1933
- Joined: 19 May 2008, 09:33
- Location: Argonne National Laboratory
- Contact:
Re: How to scan Twiss Parameter?
I'm not sure I understand the question. Do you want to scan the initial betatron phase, the betatron phase advance of a beamline, or something else?
--Michael
--Michael
Re: How to scan Twiss Parameter?
I basically want to implement a "phaseshifter" at any point of the beamline, where I would be able to increase/decrease the PSIX by any amount without affecting the optics/matching. Exactly what the TWISS parameter scanning does, but for PSIX.
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Re: How to scan Twiss Parameter?
There isn't any way I can think of to do this without using an external matrix, as you are doing.
I'll add it to the to-do list for a future version.
--Michael
I'll add it to the to-do list for a future version.
--Michael
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Re: How to scan Twiss Parameter?
Actually, I take that back. If you know the twiss parameters, I think ILMATRIX should do it. Just vary the NUX and NUY parameters.
I haven't tested this, but I think it should work.
--Michael
I haven't tested this, but I think it should work.
--Michael
Re: How to scan Twiss Parameter?
Hi Michael,
I just wanted to inquire a bit more about the "ILMATRIX" scan for NUX. I have tried doing it by adding a ILMATRIX element into the beamline I want to scan NUX as so:
But I get the error of:
I have tried toggling the length of "ILMATRIX" element, and turning the &twiss_output, matched=1 on and off. I am basically trying to only scan through the phase advance at a particular point of the beamline without affecting any other optics functions. Using an outside script and the "MATR" element to import it has been working, but now that the scope of the scan has increased I would like to use Pelegant, so one parallel job submitted would be ideal.
Thank you in advance!
I just wanted to inquire a bit more about the "ILMATRIX" scan for NUX. I have tried doing it by adding a ILMATRIX element into the beamline I want to scan NUX as so:
Code: Select all
MATRIX : ILMATRIX,l=0,BETAX=3.964955e+01,ALPHAX=2.350896,BETAY=3.875236,ALPHAY=-2.690294e-01,NUX=6.283185307179586
Code: Select all
ILMATRIX problem: divide by zero
363 matrices recomputed for periodic Twiss parameter computation
error: can't treat cavities like drifts when CHANGE_P0=1
Program trace-back:
Thank you in advance!
-
- Posts: 1933
- Joined: 19 May 2008, 09:33
- Location: Argonne National Laboratory
- Contact:
Re: How to scan Twiss Parameter?
Perhaps the attached example will help.
--Michael
--Michael
- Attachments
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- ILMatrixScan.zip
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