Background-free, quasi-monoenergetic electron beams from a self-injected laser wakefield accelerator

S. Banerjee, S. Kalmykov, N. Powers, V. Ramanathan, N. C. Smith, K. Brown, S. Chen, A. Moorthi, I. Ghebregziabher, C. Maharjan, B. Shadwick, D. Umstadter, A. Beck, E. Lefebvre, A. Cowan, D. Bruhwiler