Plasma based acceleration and intense laser and beam plasma interactions

PICKSC members and its collaborators are engaged in research aimed at advancing the understanding of basic high-energy density physics (HEDP) in the area of intense laser and particle beam plasma interactions, and employing this understanding to aid in the development of plasma-based accelerator (PBA) stages for use in high energy physics colliders, next-generation light sources, medicine, and homeland security. This effort blends basic research with three-dimensional simulations, including full-scale particle-in-cell (PIC) modeling of ongoing and planned experiments. The simulations provide a test bed for theoretical ideas and new concepts, as well as a method for guiding ongoing and future experiments. The research continues to include careful benchmarking of codes against well-diagnosed experiments.

This topic has been identified in numerous reports, including a 2003 National Academy of Sciences report, a 2004 HEDS task force report, a 2010 DOE sponsored FESAC report, and a DOE Research Needs Workshop for High Energy Density Laboratory Plasmas in 2010. It has also been highlighted on journal covers (see News).

The primary driving force for discovery driven rese­arch in intense laser ­and particle beam plasma interactions remains being plasma-based acceleration (PBA). In PBA either the space charge of a short pulse particle beam or the radiation pressure of a short pulse laser pulse (I>~1019W/cm2) pushes electrons forward and sideways as it propagates through plasma. After the pulse passes by, the space charge of the ions pulls the electrons back thereby creating a plasma wave wake. Electrons or positrons can then surf on this wake and be accelerated to ultra-high energies with gradients exceeding 10 GeV/m, i.e., at a rate 500 times that of conventional RF accelerator technology. When a laser is used this is called laser wakefield acceleration (LWFA) and when a particle beam is used it is called plasma wakefield acceleration (PWFA).

The excitation of wakes, self-trapping of particles in these wakes, manipulation of the six dimensional phase space of particles accelerated in these wakes, and the nonlinear evolution of the lasers/particle beams caused by the wakes they create is full of nonlinear, relativistic, and ultra fast physics. It also blends plasma, beam, accelerator, AMO, and laser science.

We continually update our vision for research directions for discovery driven research based on our recent progress. We believe that discovery driven basic physics research, combined with simulation and experimental efforts could lead to the design and experimental demonstration of a compact XFEL based on PBA within the next decade. If a compact XFEL could be built it could dramatically increase the rate of discovery in physical, chemical, materials, biological, and environmental sciences. In addition, a compact XFEL could also have potential use for Homeland Security. We also believe that a more detailed design of a linear collider including beam loading and staging scenarios based on PBA could begin to take shape.