Georg Hoffstaetter, Cornell University
The Energy Recovery Linac as a New X-ray Source
Physics Division Colloquium - 23 Mar 2007

Research toward a new type of x-ray source will be presented. This source is very different compared to a storage ring, where electrons are recycled for many turns in order not to lose their energy. An energy recovery linac (ERL) rather recycles energy by leading electrons that have created x-rays to a decelerating section where their energy is used to accelerate a new beam of electrons. Each x-ray beamline is thus continuously served by a newly accelerated electron beam.

After a review of how existing light-source storage-rings produce x-ray beams, their state-of-the-art limits are pointed out. It is shown how an ERL could produce improved x-ray parameters by providing beams with reduced cross section, reduced energy spread, and reduced bunch length.

At Cornell University's Center for Accelerator Sciences and Education (CLASSE) work is under way to verify the principles on which these improvements rely. An electron source and a superconducting accelerating section is currently being built and effects that can degrade beam properties are being studied. An ERL is planned as an extension to the existing CESR storage ring by implementing a 5-GeV superconducting c.w. linac. This planned upgrade illustrates how other existing storage rings could be upgraded as ERL light sources with significantly improved beam qualities and with limited dark time for x-ray users.

ANL Physics Division Colloquium Schedule