Elegant users forum

Sorry for the poor timing of this post. I see several problems with the tracking in CSBEND elements that include error terms. I've been tracking particle through bends using specific errors, rather than only looking at rms quantities. First, ETILT does not seem to work properly. This seems related t...

Thanks Mike, I appreciate the REFERENCE_CORRECTION=1 suggestion. It makes a big improvement for moderate values of N_KICKS. I am still confused about the sign convention for ETILT. A positive angle bend is making the coordinate system curve in the -x direction. If ETILT is acting in the same directi...

Thank you for the explanation Michael. That helped a lot, and I am pretty happy with the comparisons between AT and elegant using 'straight' magnets. I am having issues with comparisons in bends involving ETILT, even involving a simple ideal bend magnet, which I think comes from how I am trying to t...

I should add that I am doing this to match lattices constructed in Accelerator Toolbox. The fields of a given element can become quite complicated in AT depending on how errors and correctors are implemented. I'm working on a script to generate a nearly equivalent elegant lattice file.

I would like to model orbit correction elements which are overlapping more standard magnets. They don't have to be dynamically controlled. Is EKICKER the best way to combine a dipole kick with focusing fields if I do not want the kick to impact the coordinate system? It looks like I can't use separa...

Sorry I was too quick to see a problem before, I was reading the output like a text file and missed that the particle order was just being shuffled - I guess whenever a particle gets lost, it trades places with the last valid particle. That means if I have 1000 particles and lose 2, the end of the p...

A lot of my post-processing revolves around picking an individual particle in a bunch and seeing its trajectory, or looking at lost particles and seeing where they started, etc. The only way I know how to do this is to use a WATCH element and track particles by their particleID. For Pelegant, this s...

Thank you for the information, Mike. I will try your way of scanning momentum offests. I was all set to go the opposite route and try going backwards lots of steps. For my ALS-U runs, I do use the RF acceleration and SYNCH_RAD=1. I had it in my head it would be simpler to give an example using SPEAR...

Hi, This may seem like a philosophical question but I am having some substantive issues with calculating the MA for the ALS-U storage ring. This is a very nonlinear lattice with strong bends and sextupoles, not to mention that the fractional horizontal and vertical tunes are almost identical. I set ...

Hi Michael, Thanks, that did the trick. My workaround was to do a separate elegant run just to read in the nominal lattice, insert the elements, and save a revised lattice file using output_seq=1. With the new lattice I can still load in the same parameters file without a problem. I like your way si...