Measured Emittance Dependence on the Injection Method in Laser Plasma Accelerators

S K Barber; J van Tilborg; C B Schroeder; R Lehe; H-E Tsai; K K Swanson; S Steinke; K Nakamura; C G R Geddes; C Benedetti; E Esarey; W P Leemans

doi:10.1103/PhysRevLett.119.104801

Measured Emittance Dependence on the Injection Method in Laser Plasma Accelerators

Phys Rev Lett. 2017 Sep 8;119(10):104801. doi: 10.1103/PhysRevLett.119.104801. Epub 2017 Sep 5.

Authors

S K Barber¹, J van Tilborg¹, C B Schroeder¹, R Lehe¹, H-E Tsai¹, K K Swanson^{1

2}, S Steinke¹, K Nakamura¹, C G R Geddes¹, C Benedetti¹, E Esarey¹, W P Leemans^{1

2}

Affiliations

¹ Lawrence Berkeley National Laboratory, University of California, Berkeley, California 94720, USA.
² Department of Physics, University of California, Berkeley, California 94720, USA.

PMID: 28949165
DOI: 10.1103/PhysRevLett.119.104801

Abstract

Single-shot, charge-dependent emittance measurements of electron beams generated by a laser plasma accelerator (LPA) reveal that shock-induced density down-ramp injection produces beams with normalized emittances a factor of 2 smaller than beams produced via ionization injection. Such a comparison is made possible by the tunable LPA setup, which allows electron beams with nearly identical central energy and peak spectral charge density to be produced using the two distinct injection mechanisms. Parametric measurements of this type are essential for the development of LPA-based applications which ultimately require high charge density and low emittance.