2016-Nov-13 Comp. Phys. Biweekly Report

He Zhang:

• Wrote the report for the EIC funding call.
• In order to do a full cooling simulation and calculate all interactions (instead of using formulas like in betacool, an hermite integrator was developed. Testing has begun. Early tests show that one has to take into account diffusion, First idea was to make half of electron into positrons (to produce opposite diffusion but yet same friction force) to cancel diffusion. Another approach is to use way more particles. Code is being optimized to be able to handle that.
• Bunched cooling experiment (IMP): Shaoheng and He are working together to add a model of the potential wall due to the bunched beam into the cooling code.
• Dust Tranport in CEBAF (rongli project) . Read the initial papers and notes that Rongli send us. Problem seems slightly different than in rings. Here,in a linac, the stable motion of the dust particles is not relevant so both stable and unstable particles may accumulate. Still investigating the implications.
• Performed further optimizations and checks of the algorithm. It seems that one can handle 20 cavities bypassed at once and yet converge to a new solution within a reasonable amouint of time.
• Working with R. Huang to turn his report on the field emission work into an actual technote.

Yves Roblin:

• Wrote report on the feedback systems for the EIC funding call
• Met with Chris to update him on the status of the CEBAF ER simulations
• Formulating a new method to calculate the momentum in the CEBAF injector chicane.
• Started exploring the possibility of turning CEBAF into an low energy accumulator ring for the purpose of CSR experiments.
• In discussion via email with a colleague from CNRS regarding the use of FMM methods to calculate the space charge effects in a penning trap. They are interested in collaborating with us in this regard for an experiment on beta decay in a penning trap taking place at GANIL, France. They initially contacted us after reading a paper on GHOST.