Energy Electron Storage Rings Research Articles

The attainment of uhv in synchrotron light sources—a review

In medium-to-high energy electron storage rings, designed to operate as synchrotron light sources, the stored beam lifetime is usually determined by electron scattering from residual gas molecules. For satisfactory operation, this implies that such machines must operate in the uhv region (∼10 −9 mbar). Attaining such vacuum levels presents a challenge to the vacuum designer since the synchrotron radiation desorbs high gas loads from the walls of the system, the available pumping speed is often severely limited by vessel conductance and, in any case there is seldom any room to accommodate large vacuum pumps. This paper will review the way in which vacuum system design for light sources has evolved over the past decade; how vacuum system performance can be predicted; and the techniques, including cleaning processes, which are utilised to ensure that adequate pressures are quickly reached and maintained.

Beam Optical Properties of the NSLS Dipoles

Presently there is much interest in low energy (< 1 GeV) electron storage rings as sources of synchrotron radiation and for studies of the free electron laser. The economics and physics of these storage rings favor the use of bending magnets with small radius of curvature and large bend angle. Here we discuss some general features of such magnets and the results of magnetic mesurements of the dipole magnets of the NSLS booster and storage rings. We interpret the magnetic measurements in terms of the magnet geometry and saturation characteristics. We discuss transport functions describing the linear and nonlinear focusing properties of the magnets, parametrized in terms of their curvature and fringe field length.