FACET-II SCIENCE WORKSHOP 2019

Date: October 29 - November 1, 2019
Location: Building 40 Sycamore Conference Room, SLAC

FACET-II is a new National User Facility at SLAC National Accelerator Laboratory scheduled to begin operating in 2020. A photoinjector in a configuration similar to that of LCLS will enable FACET-II to investigate acceleration and beam quality preservation utilizing beams with an emittance two-orders of magnitude lower than what was routinely available at FACET. The resulting improvement in beam density will enable FACET-II to study new effects like the motion of plasma ions and unintended beam ionization in the plasma sources. Additional plasma-based experiments have been proposed for generating bunches with orders of magnitude lower emittance that will ultimately be needed for both an early application of a PWFA and for a plasma-based future linear collider. Phased upgrades to FACET-II are expected to provide high-intensity positron bunches, a capability unique in the world, to experimentally investigate the optimal technique for high-gradient positron acceleration in plasma.The high-intensity beams open the door to an even broader experimental program including dielectric wakefield acceleration (DWA), Strong Field QED and bright gamma bursts from plasma instabilities.

A baseline design for FACET-II has been established that progressively increases capabilities in three distinct stages and is captured in the FACET-II CDR and TDR​. Stage one completes a new photoinjector at Sector 10 and re-establishes operations with high-energy high-brightness electron beams. Stage two will add a new positron damping ring system and allow user runs with high-current positron beams. Stage three will upgrade the chicane in sector 20 for simultaneous delivery of positrons and electrons to the experimental area.

The FACET-II team is organizing the fourth in a series of workshops to (1) Communicate the facility status, capabilities and upgrade plans, (2) Review experimental installation readiness and run plans for 2019/2020, (3) Develop the science case for positrons and other upgrades and (4) Assess the opportunities and challenges of plasma driven FELs.