Quasimonoenergetic electrons from unphased injection into channel guided laser wakefield accelerators.
A high-quality electron beam can be extracted from a channel guided laser wakefield accelerator without confining the injected particles to a small region of phase. By careful choice of the injection energy, a regime can be found where uniformly phased particles are quickly bunched by the accelerator itself and subsequently accelerated to high energy. The process is particularly effective in a plasma channel because of a favorable phase shift that occurs in the focusing fields. Furthermore, particle-in-cell simulations show that the self-fields of the injected bunches actually tend to reduce the energy spread on the final beam. The final beam characteristics can be calculated using a computationally inexpensive Hamiltonian formulation when beam-loading effects are minimal.
Gordon
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Naval Research Laboratory, Plasma Physics Division, Washington, D.C. 20375, USA.
Hubbard
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Cooley
J H
JH
Hafizi
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B
Ting
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Sprangle
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