Capturing coefficient increase and energy spread decrease in LPWA

The acceleration of electrons in laser plasma channels is one of the contemporary ideas on energy frontier of accelerators. Many simulations and experimental studies are now provided. But two main laser plasma acceleration problems are not solved until now: low fraction of particles is capturing into acceleration and accelerated electrons have very broad band. Especial techniques should be proposed to preserve such negative effects. New results of beam dynamics simulations in laser plasma channel having pre-bunching stage are discussed in article. Results are obtained for two pre-bunching techniques which are analogous to waveguide and klystron type buncher used in RF accelerators (paper)