Efficient Electron Injection into Plasma Waves using Higher-Order Laser Modes.

Using higher-order transverse laser modes for plasma wakefield excitation, and, in particular, shaping a ring beam with maximum intensity off-axis, results in shifting the focusing and defocusing phase regions of a plasma wakefield accelerator. This results in a decreased trapping threshold required for electron injection and an increase of the maximum electron energy. This scheme could also be of interest as a method for generating ring electron beams. © 2006 American Institute of Physics [ABSTRACT FROM AUTHOR]