The Chasman–Green lattice, also known as a double bend achromat lattice (DBA lattice), is a special periodic arrangement of magnets designed by

Renate Chasman Renate Wiener Chasman (January 10, 1932 – October 17, 1977) was a physicist. She was born Renate Wiener to German Jewish parents in Berlin. Her father, Hans Wiener, was a founder of the Social Democratic Party of Germany. In 1938, the Wiener ...

and

George Kenneth Green George Kenneth Green (1911 – August 15th 1977) was an American accelerator physicist. Green studied at the University of California, Berkeley, where he belonged to the group of Ernest Lawrence. Later, he worked at Brookhaven National Laboratory ...

of Brookhaven National Laboratory in the mid-1970s for

synchrotron A synchrotron is a particular type of cyclic particle accelerator, descended from the cyclotron, in which the accelerating particle beam travels around a fixed closed-loop path. The magnetic field which bends the particle beam into its closed p ...

s. This lattice provides optimized bending and focusing of electrons in storage rings designed for synchrotron light sources. An electron storage ring constructed with a Chasman–Green lattice has the important property that the circulating

electron beam Cathode rays or electron beam (e-beam) are streams of electrons observed in discharge tubes. If an evacuated glass tube is equipped with two electrodes and a voltage is applied, glass behind the positive electrode is observed to glow, due to ele ...

s have very low

emittance Emittance may refer to: *Beam emittance In accelerator physics, emittance is a property of a charged particle beam. It refers to the area occupied by the beam in a position-and-momentum phase space. Each particle in a beam can be described by ...

, which results in the emission of

synchrotron light Synchrotron radiation (also known as magnetobremsstrahlung radiation) is the electromagnetic radiation emitted when relativistic charged particles are subject to an acceleration perpendicular to their velocity (). It is produced artificially in ...

of exceptional brightness. For this reason it is the lattice of choice for most of the premier synchrotron light source facilities worldwide. 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 a bending arc to an exit path that is independent of the electron energy.

References

Accelerator physics {{accelerator-stub