Incorect transfert matrix with FFAG keyword

ULB-Metronu / zgoubidoo

Python interface for Zgoubi

https://ulb-metronu.github.io/zgoubidoo/

GNU General Public License v3.0

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Incorect transfert matrix with FFAG keyword #43

Open rtesse opened 1 year ago

rtesse commented 1 year ago

After integrating the last changes in Zgoubi (13 particle methods), the transfer matrix of the keyword FFAG is no longer correct, we have the same coordinates YT0 for the particle with a LET == A and a LET == O. Here are some screenshots of the problem:

After looking into Zgoubidoo, the bug seems located at lines 108-112 in transformation.py

adamfsteinberg commented 1 year ago

Is this bug also present in FFAGSpirale / has it been fixed at some point? I can't reproduce the error for a simple spiral FFA case, where it looks like the test particles are being launched correctly.

EDIT: I have been able to reproduce the problem with a sector-scaling FFA, problem looks to be the same as in the original issue