Parallel high-performance multi-beam multi-bunch simulations

Furuseth, Sondre Vik; Buffat, Xavier

doi:10.1016/j.cpc.2019.06.006

Cited by 3 publications

(1 citation statement)

References 3 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The expressions derived for the BTF in Eqs. ( 20) and (43) will here be benchmarked against multi-particle tracking simulations run with COMBI [16,17]. Calculations made with BimBim, using the impedance model for the LHC at top energy in 2018, have been used to get the mode details required by Eq.…”

Section: Comparison To Multi-particle Tracking Simulationsmentioning

confidence: 99%

Vlasov description of the beam response to noise in the presence of wakefields in high-energy synchrotrons: beam transfer function, diffusion, and loss of Landau damping

Furuseth

Buffat

2022

Eur. Phys. J. Plus

Self Cite

View full text Add to dashboard Cite

Noise can have severe impacts on particle beams in high-energy synchrotrons. In particular, it has recently been discovered that noise combined with wakefields can cause a diffusion that leads to a loss of Landau damping after a latency. Such instabilities have been observed in the Large Hadron Collider. This paper, therefore, studies the beam response to noise in the presence of wakefields, within the framework of the Vlasov equation. First, a wakefield beam eigenmode transfer function (MTF) is derived, quantifying the amplitude of a wakefield eigenmode when excited by noise. Then, the MTFs of all the wakefield eigenmodes are combined to derive the beam transfer function (BTF) including the impact of wakefields. It is found to agree excellently with multi-particle tracking simulations. Finally, the MTFs are also used to derive the single-particle diffusion driven by the wakefield eigenmodes. This new Vlasov-based theory for the diffusion driven by noise-excited wakefields is found to be superior to an existing theory by comparing to multi-particle tracking simulations. Through sophisticated simulations that self-consistently model the evolution of the distribution and the stability diagram, the diffusion is found to lead to a loss of Landau damping after a latency. The most important technique to extend the latency and thereby mitigate these instabilities is to operate the synchrotron with a stability margin in detuning strength relative to the amount of detuning required to barely stabilize the beam with its initial distribution.

show abstract

Section: Comparison To Multi-particle Tracking Simulationsmentioning

confidence: 99%