Elegant users forum

Dear Michael, Recently I'm trying to do a simulation of the coupled-bunch effects with a time-variant quadrupole in the lattice. The quadrupole strength varies in a harmonic of the revolution frequency to introduce a bunch-by-bunch tune spread that aims to cure coupled-bunch instability. My first id...

Hi Joe, Thanks for your reply. My previous result was already using 100 macro_particle, and 128 poisson bins for both horizontal and vertical. That filling pattern was a hybrid filling pattern with 1 train, 100 half bucket gap. Following your advice, I tried another hybrid filling pattern case ( 2 t...

Dear Joe, I did some benchmarking of different 'poisson' setup parameters with my previous result using 'bilorentzian'. It seems with different filling patterns, sometimes the ion effects from 'poisson' method is more stable and sometimes 'bilorentzian' is more stable. But I observed some interestin...

Hi Joe,

Many thanks for your reply. I'll try more cases with different number of bins. It's a good thing that 'poisson' method is closer to measurement result, it will save more execution time for ion simulation for future studies.

Regards,
Siwei

Hi there, Recently I noticed that the newest elegant 2023.2 has the new ‘poisson’ method in ‘ion-effects’. I did several tests with different settings of ion_span and ion_poisson_bins. When I set the ion_span to 10 times the beam sigma and ion_poisson_bins to 128, the simulation goes much faster tha...

Dear Soliday, I seems to find a way of overcoming this problem. Currently in my pressure file, I have only two lines of data corresponding the start and end of the lattice. After I duplicate the pressure data in some middle points, making 11 lines of the total data, it seems the problem is gone. I c...

Dear all, When I run ion-effects simulation, sometimes I encounter the following errors: *** Error in `/dls/physics/wsw/ELEGANT2022/2022/bin/Pelegant': realloc(): invalid old size: 0x0000000001c48870 *** ======= Backtrace: ========= /lib64/libc.so.6(+0x7f474)[0x2ac4b92f6474] /lib64/libc.so.6(+0x8486...

Hi Joe, It seems for my case, the bi-lorentzian fit gives a result that looks a little better than bi-gaussian. The charge distribution looks more like a concave curve but the bigaussian gives a more convex curve. And the gaussian fit feels underestimated the charge distribution. Here are the three ...

Hi Joe, Many thanks for the reply. This is also what I observed in my simulation, I did a case with a strong vacuum pressure which leads to strong ion instability. I tested the same case with both 'gaussian' and 'bigaussian', and the 'gaussian' gives a stable result while 'bigaussian' gives an obvio...

Hi, Recently I'm trying to simulate ion effects. When I changed the field_calculation_method from 'gaussian' to 'bigaussian', I encountered a huge increase in execution time, maybe 10 times slower. I'm using ILMATRIX and only one interaction point per turn, and macro_ions=1, it is already very slow....