CEA Codes forum

Dear Didier,
I used the matching option (1) Calculate input matched beam to calculate matched beam for a FFDD period, and found the calculated result is:

Twiss_parameters_of_matched_beam ; Criterion=1.958483e-011
0.5058262122 0.1630822965 0.2914046369
1.8464836872 -1.0570016401 -0.0124267708

but the multiparticle simulation shows the input matched beam is as following, the beam ellipses are different with the matching results. I don't know why. I attached the lattice files.

Dear Emily,

I ran the Tracewin project you sent and it worked fine. In fact, the results of the matching are written in the '.cal' file in the following order:

Twiss_parameters_of_matched_beam
betax betay betaz
alphax alphay alphaz

Then, if you plot beam distributions in the different phase spaces and if you check the Twiss parameters, you will see that they are the same as the ones found by the optimisation. In the figure you've attached, the first distribution (on the left) is plotted in the "x-y" plane. If you change to the "x-x'" plane, you will see that the Twiss parameters are compatible with the matching results (like in the other planes).

I hope it helped

Regards,

Nicolas.

Dear Nicolas,
Yes, you are right. I am so happy that the problem is solved. I checked other parts of the simulation but ignored the phase plane.
Thank you very much!

Regards,

Emily