THOBI01
LBNL, Berkeley, California, USA
Present laser-plasma accelerator (LPA) experiments at LBNL produce up to 1 GeV electron beams in cm-scale plasmas using tens of TW laser pulses. Such beams have been successfully coupled to a conventional undulator, producing synchrotron radiation. Presently, beam quality limits FEL applications. In this paper we discuss methods of triggered electron beam injection into a laser-plasma accelerator to improve the beam quality. Laser-triggered injection, ionization injection, and the use of plasma density tailoring will be discussed. Short pulse, PW laser systems are presently under constructed, and future experiments using PW lasers aim at the production of 10 GeV electron beams accelerated over less than 1 m of plasma. We report on progress toward achieving compact 10 GeV electron beams using BELLA (Berkeley Lab Laser Accelerator).
LBNL, Berkeley, California, USA
SLAC, Menlo Park, California, USA
Uni HH, Hamburg, Germany
Plasma waves excited by high-intensity, short-pulse lasers are able to generate hundreds of GV/m accelerating fields, enabling extremely compact accelerators for applications such as radiation generation. Laser-plasma accelerators (LPAs) produce ultrashort (femtosecond), 0.1-1 GeV electron bunches with high-peak (kA) currents and low (sub-micron) normalized transverse emittance, with 6D beam brightness comparable to state-of-the-art RF linac-based sources. FEL applications are presently limited by the longitudinal phase space distribution of the LPA beam. Beam phase space manipulation is considered to enable the application of LPA beams to FELs. LPA beam decompression (such that the energy spread over a coherence length is less than the FEL parameter) is examined as a path toward realizing an LPA-driven VUV FEL. The possibility of using a flat beam, with an energy correlation with transverse position, in a transverse gradient undulator is also explored. Laser-based FEL seeding options for improved coherence are considered.