intrabeam scattering with IBSCATTER

[tiansk]

Dear all,
I intend to track the electron bunch in storage ring with IBSCATTER element to simulate the IBS effect. I want to know that:How to bring in coupling(emit_y/emit_x) in the lattice ？I found the element SREFFECTS has a Parameter Name：COUPLING
if I set the COUPLING=0.01，is it that during the particle tracking,the parameter of electron bunch from WATCH element emit_y/emit_x keep 0.01? The attached files was the example I used for IBSCATTER.I think I should get the same result as

https://jacowfs.jlab.org/conf/y15/ipac1 ... PMA012.PDF
but the variation of the vertical emittance is strange,Is there any way I could do in the example?


Thanks in advance!
Tiansk

[tiansk]

Dear all,

The attached file is the result of particle tracking with IBSCATTER and SREFFECTS(COUPLING=0.01),the emittance of y direction is not growing so much! If using the ibsEmittance command,the final emittance_y/emittance_x will be equal with the coupling factor.Should I add some tilt bends or quads in the lattice？

Thanks in advance!
Tiansk

[simone.dimitri]

Dear all,
I am asking a very similar question of Tiansk: the agreement of ibsEmittance and tracking results on the horizontal emittance is fine. Instead, tracking does not reproduce the vertical emittance growth predicted by ibsEmittance. I also tried to include coupling sources in the lattice through quad roll errors, without success.
Any help to fix it? I am attaching elegant files and plots.
Thank you in advance,
Simone

p.s.: in order to enhance the IBS effect, the bunch charge was made huge, but this does not change the situation.

[tiansk]

Dear all:

When using IBSCATTER to simulate the IBS effect, there is a parameter called SMOOTH in IBSCATTER. I believe that setting SMOOTH to 1 or 0 may result in different paths for the variation of beam parameters, but the final equilibrium state should be relatively consistent. However, after comparing the results with different SMOOTH settings, I found that the beam equilibrium state parameters differ significantly, as shown in the attached files. How can this be explained?


Thank you in advance,
Tiansk

[tiansk]

The change in the vertical emittance is shown in the figure below.