Operation and Performance of the University of Wisconsin - Physical Sciences Laboratory Electron Storage Ring

Abstract

A 240 MeV electron storage ring has been in operation at the Physical Sciences Laboratory of the University of Wisconsin for one year. The storage ring injector is a 50 MeV FFAG electron synchrotron. The bunched beam from the synchrotron is injected into the storage ring in a single turn. Radio-frequency capture is accomplished by using the signal from the bunched beam as the master oscillator during capture. Using this method, high capture efficiency is achieved. A useful consequence of the method of radio-frequency capture is the damping of the coherent synchrotron oscillation instability. The beam may be accelerated, or decelerated, to any energy within the capability of the ring -10 MeV to 240 MeV. The vacuum system operates at a pressure in the mid 10-10 range allowing lifetimes of many hours for low intensity beams. During the first year of operation several interesting effects have been observed. Among these were photo etching of metal from the vacuum chamber by synchrotron radiation and enhanced beam loss due to scattering from ions trapped in the electron beam. The beam also exhibits a transverse coherent instability that violates the Courant-Sessler criteria for stability.

Optical Properties of Alkali Halides in Ultraviolet Spectral Regions

“…Band structure calculations for the ionic crystals show that the valence bands, originating from the filled p states of the negative ions (halogen ions), are about 0.75 eV wide [2][3][4][55][56][57][58]. The corresponding wave functions are localized on the negative halogen ions sites, and have a strong p character [55,58]. The important structure in the valence band is determined by the spin-orbit splitting parameter η.…”

Accelerator-based X-ray sources: synchrotron radiation, X-ray free electron lasers and beyond

“…SRS is the world's first second-generation X-ray synchrotron radiation facility which started user operation a little earlier than the National Synchrotron Light Source (NSLS) at the Brookhaven National Laboratory in the USA [7] or the Photon Factory in Japan [8], both of which started user operations in 1983. These second-generation sources covering the X-ray region followed earlier secondgeneration sources covering the VUV/SX region: Tantalus at Wisconsin, USA, in 1968 [9] and SOR-RING at Tokyo in 1974 [10]. The independence from high-energy physics programmes that these second-generation sources provided allowed SR users to conduct important research specific to SR science and technology.…”