Plasma Acceleration - Comparison With RF Acceleration

Comparison With RF Acceleration

The advantage of plasma acceleration is that its acceleration field can be much stronger than that of conventional radio-frequency (RF) accelerators. In RF accelerators, the field has an upper limit determined by the threshold for dielectric breakdown of the acceleration tube. This limits the amount of acceleration over any given area, requiring very long accelerators to reach high energies. In contrast, the maximum field in a plasma is defined by mechanical qualities and turbulence, but is generally several orders of magnitude stronger than with RF accelerators. It is hoped that a compact particle accelerator can be created based on plasma acceleration techniques or accelerators for much higher energy can be built, if long accelerators are realizable with an accelerating field of 10 GV/m.

Plasma acceleration is categorized into several types according to how the electron plasma wave is formed:

• plasma wakefield acceleration (PWFA): The electron plasma wave is formed by an electron bunch
• laser wakefield acceleration (LWFA): A laser pulse is introduced to form an electron plasma wave.
• laser beat-wave acceleration (LBWA): The electron plasma wave arises based on different frequency generation of two laser pulses.
• self-modulated laser wakefield acceleration (SMLWFA): The formation of an electron plasma wave is achieved by a laser pulse modulated by stimulated Raman forward scattering instability.

The first experimental demonstration of wakefield acceleration, which was performed with PWFA, was reported by a research group at Argonne National Laboratory in 1988.