Introduction to Acceleration Phenomena in Plasma Introduction to the Laser Wakefield Accelerator

-R-~-~~~ ~~tl ~j~~~*~~/ ~ JV;~ ~:~~;~ ~ j ~ ~7 O)f~~f~;~1 VI: 5. 1 ~ x7 eC ~5 e ~ ~ ~D~~~~~~o)~;~*~~ * 5.3 ~-tF-~:~~it~~D*~ :~~ ~ ~(.* ~;~ ~ ( H ;~c~;~~~ ~J ~~*~~F~~'i~) (1997~~ 5 FI 12 A -**~~!) Abstract The basic principles and intrinsic limitations of the laser wakefield accelerator are discussed. The necessity of introducing optical guiding of laser pulses in order to achieve high energy gain of electrons in plasma-based accelerators is discussed. Our recent experiments, which attained an energy gain of over 300 MeV in 20 mm acceleration length, are described.