ANL, Argonne
Funding: Work supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357.
The Advanced Photon Source (APS) is a third-generation storage-ring-based x-ray source that has been operating for more than 11 years and is enjoying a long period of stable, reliable operation. While APS is presently providing state-of-the-art performance to its large user community, we must clearly plan for improvements and upgrades to stay at the forefront scientifically. Significant improvements should be possible through upgrades of beamline optics, detectors, and end-station equipment, along with local, evolutionary changes to the storage ring itself. However, major accelerator upgrades are also being investigated. One very promising option that has been the subject of considerable research is the use of an energy recovery linac. In this option, APS would transition from a source based on a stored electron beam to one based on a continuously generated high-brightness electron beam from a linac. Such a source promises dramatically improved brightness and transverse coherence compared to third-generation storage rings, as well as distinctly different temporal properties.
ANL, Argonne
Funding: Work supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357.
An energy recovery linac (ERL) is a potential candidate for an Advanced Photon Source (APS) upgrade at Argonne National Laboratory. A high-DC-voltage photocathode-gun-based electron injector* was previously investigated to meet the ultra-low emittance requirement. Recently the modeling was extended to include a merger using the fully three-dimensional tracking simulation code IMPACT-T. A multiobjective numerical optimization was performed with the goal of delivering a 10-MeV, 19-pC bunch with a normalized transverse emittance less than 0.1 μm at the entrance of the linac. In this paper we show the optimum performance obtained.
*Y.-E. Sun et al., ”Optimization of a DC Injector for an Energy Recovery Linac Upgrade to the Advanced Photon Source”, Proc. of LINAC 2008, TUP100, to be published on http://www.jacow.org.