Issue with moments_output for a very perturbed ring
Posted: 30 Mar 2020, 20:25
Hi,
I have been looking at the ALS-U ring with large errors that have been corrected with kicker magnets and other adjustments. The final beamline was converted from AT simulations. Although it looks like there is a closed orbit, moments_output produces the following error message:
Warning: particle acquired undefined slopes when integrating through kick multipole
Sometimes I managed to get the moments_output calculation to complete by tweaking the lattice, but there were nonsensical results including negative emittances. There are also some MKL errors.
Does this mean that all elegant calculations will be unreliable, or is it just a problem that moments_output
cannot converge to an answer? When tracking a single particle everything looks reasonable, but the transverse motion is limited due to the apertures.
Example is attached. I apologize for the very long lattice file, I'm not sure how to reduce the problem further.
-Gregg
I have been looking at the ALS-U ring with large errors that have been corrected with kicker magnets and other adjustments. The final beamline was converted from AT simulations. Although it looks like there is a closed orbit, moments_output produces the following error message:
Warning: particle acquired undefined slopes when integrating through kick multipole
Sometimes I managed to get the moments_output calculation to complete by tweaking the lattice, but there were nonsensical results including negative emittances. There are also some MKL errors.
Does this mean that all elegant calculations will be unreliable, or is it just a problem that moments_output
cannot converge to an answer? When tracking a single particle everything looks reasonable, but the transverse motion is limited due to the apertures.
Example is attached. I apologize for the very long lattice file, I'm not sure how to reduce the problem further.
-Gregg