Chasman-Green lattice

Renate Chasman and G. Kenneth Green were scientists at the U.S. Department of Energy’s Brookhaven National Laboratory in Upton, NY, who invented a special periodic arrangement of magnetic elements - a so-called magnetic lattice – to provide optimized bending and focusing of electrons in a new class of particle accelerator rings known as synchrotron light sources [1-3] . Each period of the Chasman-Green lattice contains a focusing quadrupole magnet symmetrically located between a pair of identical dipole magnets, which transports incident electrons through this bending arc to an exit path that is independent of the electron energy. The Chasman-Green lattice is thus also known as the double bend achromat (DBA) lattice.

An electron storage ring constructed with a Chasman-Green lattice has the important property that the circulating electron beams have very low emittance, which results in the emission of synchrotron light of exceptional brightness. For this reason the Chasman-Green lattice is the lattice of choice for most of the premier synchrotron light source facilities worldwide [4] .

1.) R. Chasman, G.K. Green and E.M. Rowe, IEEE Trans. Nucl. Sci. NS-22, 1765 (1975).
2.) R. Chasman and G.K. Green, BNL-21849 (1976)
3.) Proposal for a National Synchrotron Light Source, Ed, J. Blewett, BNL 50595, Vol. I (1977).
4.) Advanced Photon Source [http://www.aps.anl.gov] , European Synchrotron Radiation Facility [http://www.esrf.eu] , National Synchrotron Light Source [http://www.nsls.bnl.gov] and SPring-8 [http://www.spring8.or.jp]