A high-energy, laser accelerator for electrons using the inverse Cherenkov effect

TLDR

The paper proposes a laser-based electron accelerator that exploits the inverse Cherenkov effect in gas. The scheme uses a cylindrical cone of plane-wave laser fields aligned with the electron axis, producing constant fields that transfer energy proportional to laser power, wavelength, gas index, and interaction length, and a comparative vacuum-based evanescent-field variant is also examined. With current laser powers, the method can impart tens of GeV to electrons and is especially suitable for boosting electron bunches from large microwave accelerators, where high injection energies reduce collision effects.

Abstract

A laser method for accelerating electrons is described, based on the inverse Cherenkov effect in a gas. The laser fields are in the form of a cylindrical cone of plane waves on whose axis travel the electrons, with the cone angle and the gas refraction index such that each electron sees constant fields in time. Expressions are obtained relating the overall energy transfer to total laser power and wavelength, and to gas index and interaction length. With laser powers now available, energy increments of tens of GeV are possible. For comparative purposes, a related alternative scheme involving electrons in vacuum and evanescent laser fields is also analyzed. It is found that the method applies particularly well to adding energy to the electron bunches produced by large microwave accelerators, as collision effects are less troublesome at high injection energies.