FACET—Facility for Advanced aCcelerator Experimental Tests at SLAC—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 is one of two facilities that will meet the Department of Energy Mission Need Statement for an Advanced Plasma Acceleration Facility. With FACET, the SLAC linac will support a unique program concentrating on 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.

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 make significant advances using 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.

FACET construction is expected to finish in early 2011 with accelerator and beam commissioning soon after. The experimental program will begin in the Spring of 2011. FACET is currently envisioned to run 4 months per year, roughly one month per quarter, with experiments allocated blocks of time lasting from 1-4 weeks.

A request for experimental proposals will be announced shortly. We will hold the first users workshop at SLAC on March 18-19, 2010 to inform the user community regarding FACET's capabilities, near-term R&D program, and the process for submitting proposals for new experiments.