Theoretical and Computational Modeling of a Plasma Wakefield BBU Instability
Plasma wakefield accelerators achieve accelerating gradients on the order of the wave-breaking limit, m c² k_{p}/e, so that higher accelerating gradients correspond to shorter plasma wavelengths. Small-scale accelerating structures, such as plasma and dielectric wakefields, are susceptible to the beam break-up instability (BBU), which can be understood from the Panofsky-Wenzel theorem: if the fundamental accelerating mode scales as b⁻¹ for a structure radius b, then the dipole mode must scale as b⁻³, meaning that high accelerating gradients necessarily come with strong dipole wake fields. Because of this relationship, any plasma-accelerator-based future collider will require detailed study of the trade-offs between extracting the maximum energy from the driver and mitigating the beam break-up instability. Recent theoretical work* predicts the tradeoff between the witness bunch stability and the amount of energy that can be extracted from the drive bunch, a so-called efficiency-instability relation . We will discuss the beam break-up instability and the efficiency-instability relation and the theoretical assumptions made in reaching this conclusion. We will also present preliminary particle-in-cell simulations of a beam-driven plasma wakefield accelerator used to test the domain of validity for the assumptions made in this model.
- Research Organization:
- Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC), High Energy Physics (HEP)
- DOE Contract Number:
- AC02-07CH11359
- OSTI ID:
- 1527391
- Report Number(s):
- FERMILAB-CONF-18-774-APC; 1736160
- Resource Relation:
- Conference: 13th International Computational Accelerator Physics Conference, Kwy West, FL, USA, 10/20-10/24/2018
- Country of Publication:
- United States
- Language:
- English
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