sddsmatch (issues?)

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Philippe Piot
Posts: 83
Joined: 20 Aug 2008, 13:18
Location: Northern Illinois University & Argonne National Laboratory
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sddsmatch (issues?)

Post by Philippe Piot » 22 Aug 2011, 14:10

Hi,

I am using sddsmatch to perform a series of matching as part of an optimization algorithm. I just noticed some awkward behavior, rematching, e.g., the horizontal Courant-Snyder parameters messes the transverse horizontal emittance, and for some cases the parameter I am trying the set do not reach the value. Here is an example:

1 *** I first analyse the distribution (attached) distexmple.sdds
[piot@node1 August2011]$ sddsanalyzebeam distexmple.sdds -pipe=out | sddsprintout -pipe=in -column=pAverage -column=alphax -column=betax -column=enx -column=alphay -column=betay -column=eny -column=Ss -column=Sdelta -column=s56 -column=s55
warning: no column matches Ss
Printout for SDDS file stdin

pAverage alphax betax enx alphay betay eny Sdelta
s56 s55
m m m m
s s$a2$n
------------------------------------------------------------------------------------------------------------------------
1.222213e+01 1.086602e+02 2.163274e+01 7.808927e-12 1.296249e+02 2.581368e+01 8.707101e-12 3.676671e-04
7.284417e-18 3.925626e-28

2 *** Now I rematch the alpha_x and beta_x of distexmple.sdds to (70,30)
[piot@node1 August2011]$ sddsmatchtwiss distexmple.sdds tmp1 -xPlane=alpha=70,beta=30

3 *** Finally I analyse the rematched distribution output
[piot@node1 August2011]$ sddsanalyzebeam tmp1 -pipe=out | sddsprintout -pipe=in -column=pAverage -column=alphax -column=betax -column=enx -column=alphay -column=betay -column=eny -column=Ss -column=Sdelta -column=s56 -column=s55
warning: no column matches Ss
Printout for SDDS file stdin

pAverage alphax betax enx alphay betay eny Sdelta
s56 s55
m m m m
s s$a2$n
------------------------------------------------------------------------------------------------------------------------
1.222213e+01 1.936840e+01 8.283201e+00 2.827056e-11 1.296249e+02 2.581368e+01 8.707101e-12 3.676671e-04
7.284417e-18 3.925626e-28


****
I notice the target (alpa,beta)=70,30 m are not reached and the emittance enx blows up.

Thank for any suggestion. (I attached the distexmple.sdds ). -- Philippe.
Attachments
distexmple.sdds
distrubution I am trying to rematch with sddsmatchtwiss
(105.7 KiB) Downloaded 2105 times

michael_borland
Posts: 1933
Joined: 19 May 2008, 09:33
Location: Argonne National Laboratory
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Re: sddsmatch (issues?)

Post by michael_borland » 22 Aug 2011, 14:42

Philippe,

You should give the -correctedOnly option to sddsanalyzebeam. Otherwise, the beta and alpha values will include any dispersive beam size and divergence that might be present. Alternatively, look only at the "corrected" values (e.g., betacx).

--Michael

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