A long, relativistic particle beam propagating in an overdense plasma is subject to the self-modulation instability. This instability is analyzed and the growth rate is calculated, including the phase relation. The phase velocity of the wake is shown to be significantly less than the beam velocity. These results indicate that the energy gain of a plasma accelerator driven by a self-modulated be...

Abstract Plasma-based positron sources are attracting significant attention from the research community, thanks to their rather unique characteristics, which include broad energy tuneability and ultra-short duration, obtainable in a compact relatively inexpensive setup. Here, we show detailed numerical study of beam characteristics at dedicated user target areas proposed for EuPRAXIA facility, ...

Travis M. Austin, ∗ John R. Cary, Serguei Ovtchinnikov, Gregory R. Werner, and Leo Bellantoni Tech-X Corporation, 5621 Arapahoe Ave., Ste. A, Boulder, CO 80303, USA Tech-X Corporation, 5621 Arapahoe Ave., Ste. A, Boulder, CO 80303, USA; Center for Integrated Plasma Studies, University of Colorado, Boulder CO 80309, USA Center for Integrated Plasma Studies, University of Colorado, Boulder CO 803...

The hollow plasma channel is analyzed as an accelerating structure. The excitation of the channel by an ultra-relativistic beam is analyzed. Coupling to the fundamental and all higher order azimuthal modes of the excited electromagnetic elds is derived. Implications of this work for plasma-based accelerators, including beam loading and beam breakup, are discussed. Small initial transverse displ...