Observation of laser power amplification in a self-injecting laser wakefield accelerator by Streeter, MJV, Kneip, S, Bloom, MS, Bendoyro, RA, Chekhlov, O, Dangor, AE, Döpp, A, Hooker, CJ, Holloway, J, Jiang, J, Lopes, NC, Nakamura, H, Norreys, PA, Palmer, CAJ, Rajeev, PP, Schreiber, J, Symes, DR, Wing, M, Mangles, SPD, Najmudin, Z