PEP-X: Concepts for a Future Light Source for SSRL

Abstract

In a world where new storage ring light sources are pushing electron beam emittances to the nanometer-radian scale and below, producing photon beam brightness exceeding 1021 (ph/s/mm2/mrad2/0.1% BW) for multi-keV photons, the long-term future of the Stanford Synchrotron Radiation Lightsource (SSRL) may depend on a much higher performing light source than that provided by the 3-GeV SPEAR3 storage ring. SPEAR3, having an emittance of 10 nm-rad and commissioned in 2003, produces an order of magnitude lower brightness than these new sources, although with 500-mA stored beam current it is a prodigious source for flux-limited applications such as many spectroscopy applications. Incremental improvements to the machine over the next few years, which include reducing the emittance by another factor of two, will enhance science capabilities even further. Nevertheless, the lab is looking forward to a future source that far exceeds the performance of SPEAR3, enabling advanced capabilities in imaging and other areas made possible with very high coherence and brightness, and that could establish a new state of the art for performance from a ring-based light source.