Longitudinal tracking using sdds_beam
Posted: 04 Oct 2018, 09:17
Hi,
I want to use elegant to do longitudinal tracking of different fill patterns with a passive harmonic cavity. I am attempting to modify the APS-24Bunch-CBI for my case. For testing I have started with no harmonic cavity and the main cavities without beam loading by using RFCA. So far I have managed to set up the ilmatrix and sreffects and got the simulation to run using bunched_beam. Now I want to change to use sdds_beam instead to have many bunches, but I have run into problems.
- I started using a bunch with 1000 particles and tried to create a second bunch with n_duplicates = 1 and offsetting it longitudinally using duplicate_stagger[4] as in the example. However, it only works if I have duplicate_stagger[4] = 0. If I try offsetting the second bunch according to the bunch spacing given by the RF frequency the particles in the second bunch is lost. Depending on what offset I use (for example two bunches after each other or two bunches equally spaced around the ring) particles in the first bunch is sometimes also lost. Is it not possible to combine sdds_beam with RFCA so I have to model the RF cavities using RFMODE?
- For testing I decided to simplify my simulation to only use 1 particle per bunch. Using sdds_beam that works when only having one bunch, but when adding n_duplicates = 1 the simulation gets stuck. The output says that I have 2 particles that should be tracked, but the tracking never starts. Can there be a problem with the fiducialization when having only 1 particle per bunch? I tried different settings related to the fiducialization, but none helped.
Best regards,
Teresia
I want to use elegant to do longitudinal tracking of different fill patterns with a passive harmonic cavity. I am attempting to modify the APS-24Bunch-CBI for my case. For testing I have started with no harmonic cavity and the main cavities without beam loading by using RFCA. So far I have managed to set up the ilmatrix and sreffects and got the simulation to run using bunched_beam. Now I want to change to use sdds_beam instead to have many bunches, but I have run into problems.
- I started using a bunch with 1000 particles and tried to create a second bunch with n_duplicates = 1 and offsetting it longitudinally using duplicate_stagger[4] as in the example. However, it only works if I have duplicate_stagger[4] = 0. If I try offsetting the second bunch according to the bunch spacing given by the RF frequency the particles in the second bunch is lost. Depending on what offset I use (for example two bunches after each other or two bunches equally spaced around the ring) particles in the first bunch is sometimes also lost. Is it not possible to combine sdds_beam with RFCA so I have to model the RF cavities using RFMODE?
- For testing I decided to simplify my simulation to only use 1 particle per bunch. Using sdds_beam that works when only having one bunch, but when adding n_duplicates = 1 the simulation gets stuck. The output says that I have 2 particles that should be tracked, but the tracking never starts. Can there be a problem with the fiducialization when having only 1 particle per bunch? I tried different settings related to the fiducialization, but none helped.
Best regards,
Teresia