Observation of the Self-Modulation Instability via Time-Resolved Measurements.

Research paper by M M Gross, J J Engel, J J Good, H H Huck, I I Isaev, G G Koss, M M Krasilnikov, O O Lishilin, G G Loisch, Y Y Renier, T T Rublack, F F Stephan, R R Brinkmann, A A Martinez de la Ossa, J J Osterhoff, et al.

Indexed on: 26 Apr '18Published on: 26 Apr '18Published in: Physical review letters


Self-modulation of an electron beam in a plasma has been observed. The propagation of a long (several plasma wavelengths) electron bunch in an overdense plasma resulted in the production of multiple bunches via the self-modulation instability. Using a combination of a radio-frequency deflector and a dipole spectrometer, the time and energy structure of the self-modulated beam was measured. The longitudinal phase space measurement showed the modulation of a long electron bunch into three bunches with an approximately 200  keV/c amplitude momentum modulation. Demonstrating this effect is a breakthrough for proton-driven plasma accelerator schemes aiming to utilize the same physical effect.