FACET is a unique R&D facility for experimental beam physics using the SLAC linac. FACET will provide high energy density electron and positron beams with peak currents of roughly 20 kA that are focused down to a 10x10 micron transverse spot size at an energy of 23 GeV. FACET's unique high-power beams will provide important science opportunities in many fields.
FACET was designed to meet the Department of Energy Mission Need Statement for an Advanced Plasma Acceleration Facility. A key component of the experimental program at FACET will be second-generation research in plasma wakefield acceleration. Topics include high-gradient electron acceleration with narrow energy spread and preserved emittance, efficiency, high-gradient positron acceleration and radiation generation. This program of FACET research is directed at understanding and establishing plasma wakefield acceleration as a viable particle acceleration technique. Researchers interested in plasma wakefield acceleration are encouraged to propose a multi-year program addressing the critical issues for this technology.
In addition to the plasma wakefield acceleration research, FACET will support a broad user program in accelerator science, materials science, high-energy density physics and other fields of research that can take advantage of these intense beams and the intense fields that are generated. Examples of possible topics of study include dielectric wakefield acceleration, materials study in extreme conditions, and novel sources of radiation using plasmas, crystals and meta-materials.
There will be roughly four months of beam time per year and the beam time will be allocated between a Plasma Wakefield Acceleration program and a general Beam Physics research program. The four months of beam time will be distributed throughout the year. Approved experiments will be allocated beam time for blocks roughly 1-3 weeks long operating 24 hours per day 7 days per week. The nominal beam parameters at the FACET experimental area are listed at the FACET website. The experimental infrastructure available to support an experiment is described at the FACET website.
It is planned that new proposals will be solicited twice per year. Each proposal round will be treated independently; however ongoing research themes will be given consideration. In the case of the plasma wakefield research program we specifically encourage the formation of a broad collaboration to develop both individual research proposals and an overall strategic plan for demonstrating an understanding of this approach as a particle acceleration technique. Proposals submitted to FACET are peer reviewed by the SLAC Accelerator Research Program Advisory Committee. The highest rated proposals are most likely to be offered beam time approximately one year after submission.
The first call for FACET proposals for the Plasma Wakefield Acceleration and the general Beam Physics programs was May 30, 2010 (proposals must be received by midnight PDT on Sunday, May 30, 2010 to be considered for beam time during the June 2011 – June 2012 run cycle). The next call is expected to be in the fall of 2011. There was a FACET Users Workshop in March, 2010 to provide additional information regarding the beam parameters and the proposal process.