Minutes from Beamdynamics meeting

Daniel started by presenting the two new staff members (Rogelio and Giovanni)

Tour de Table:

Warner explained that he is testing his new electron cloud tracking code and then document this work. Daniel asked about the effect of using many bunches for the simulations. For the moment Warner is using 10-20 bunches. Giovanni, Daniel and Warner will meet to discuss multibunch simulations for electron cloud and also fast beam-ion instabilities in more detail.

Francesco asked about secondary emission when particles hit the walls. So far this is not included in the code, but it should be done.

Andrea reported that the Kalman-filter feedbacks for Placet work now. The neural network feedbacks still do not work, probably some debugging needed. He also mentioned that Placet is now available in a CVS repository in the Savannah portal. The code is cleaned (or almost cleaned) from NR code.

Takao explained that he has started to optimise the optics for the CLIC FFS. He is doing this using a program written by A. Seryi. He is running the simulations w. SAD. He will present results before end of November.

Maxim said that he is currently studying field tolerances using MAD8. He would like to use another code though. Will present first results for the sensitivity in the BDS at the next meeting.

Francesco proposed to prepare some kind of list of actions for future beam dynamics meetings.

Helmut said that he would like to get some feedback on halo and tail generation processes. What should be done?

Daniel pointed out that halo and tail simulations should be integrated in the Placet. Implementation in Merlin should be discussed w. Stefano Redaelli.

Peder said that he is for the moment finishing a EUROTev paper on dispersion and wakefield bumps in the ILC linac. This will probably be done before the end of the week. Then he should start including dynamic imperfections into those simulations.

Daniel showed some results from BDS alignment using one-to-one steering. The non-linearity cause some problems even when using very small iteration steps. Initially some BPM readings increase, but after 40 iterations the BDS is aligned. He also mentioned that he is working on getting a cluster of computers for parallel processor particle tracking. Computer will probably come in the beginning of next year.

Javier reported on his work on a new lattice for the non-linear collimation. He has been studying the cleaning efficiency using MAD. Recently discovered that the luminosity is one order of magnitude lower than the nominal one. This has to be sorted out and explained at the next meeting.

Lionel explained that he is going through the list of processes that contribute to halo generation. He should also start implementing modules for multiple scattering and bremsstrahlung, that can be used for beam-gas and collimator simulations

Francesco finally wondered if MAD-X should be added to Savannah as well. According to Helmut this has already been discussed.