Effect of beam emittance on self-modulation of long beams in plasma wakefield accelerators

Abstract

The initial beam emittance determines the maximum wakefield amplitude that can be reached as a result of beam self-modulation in the plasma. The wakefield excited by the fully self-modulated beam decreases linearly with the increase of the beam emittance. There is a value of initial emittance beyond which the self-modulation does not develop even if the instability is initiated by a strong seed perturbation. The emittance scale at which the wakefield is twice suppressed with respect to the zero-emittance case (the so called critical emittance) is determined by inability of the excited wave to confine beam particles radially and is related to beam and plasma parameters by a simple formula. The effect of beam emittance can be observed in several discussed self-modulation experiments.

6 pages, 10 figures, 1 table

References in corpus (6)

• Physics of beam self-modulation in plasma wakefield accelerators
• Hosing Instability Suppression in Self-Modulated Plasma Wakefields
• Electron trapping and acceleration by the plasma wakefield of a self-modulating proton beam
• Ion motion in the wake driven by long particle bunches in plasmas
• Parameter sensitivity of plasma wakefields driven by self-modulating proton beams
• Self-modulation instability of ultra-relativistic particle bunches with finite rise times

Cited by in corpus (7)

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• Wakefield decay in a radially bounded plasma due to formation of electron halo
• Proton beam self-modulation seeded by electron bunch in plasma with density ramp
• Evolution of equilibrium particle beams under external wakefields
• Multi-proton bunch driven hollow plasma wakefield acceleration in the nonlinear regime
• Generation of controllable plasma wakefield noise in particle-in-cell simulations