Global Coupling and Decoupling of the APS Storage Ring
نویسندگان
چکیده
This paper describes a study of controlling the coupling between the horizontal and the vertical betatron oscillations in the APS storage ring. First, we investigate the strengthening of coupling using two families of skew quadrupoles. Using smooth approximation, we obtained the formulae to estimate the coupling ratio defined as the ratio of the vertical and horizontal emittances or, for a single particle, the ratio of the maximum values of the CourantSnyder invariants. Since we knew that the coupling is mostly enhanced by the 21st harmonic content of skew quadrupole distribution, we carried out the harmonic analysis in order to find the optimum arrangement of the skew quadrupoles. The numerical results from tracking a single particle are presented for the various configurations of skew quadrupoles. Second, we describe the global decoupling procedure to minimize the unwanted coupling effects. These are mainly due to the random roll errors of normal quadrupoles. It is shown that even with the rather large rms roll error of 2 mrad we can reduce the coupling from 70 percent to 10 percent with a skew quadrupole strength which is one order of magnitude lower than the typical normal quadrupole strength.
منابع مشابه
Tkeatment of Weak Coupling Using Smooth Approximation
This paper describes a study of controlling the coupling between the horizontal and the vertical betatron oscillations in the APS storage ring. Firit, we investigate the strengthening of coupling using two families of skew quadrupoles. Using smooth approximation, we obtained the formulae to estimate the coupling ratio defined as the ratio of the vertical and horizontal emittances or, for a sing...
متن کاملStorage Ring Isolation Valve
The RF impedance of the sector isolation valve of the APS storage ring system was measured by the wire method with a synthetic pulse technique [1]. The coupling impedance as well as the energy loss of the isolation valve with and without an RF liner or screen, and the flange gap of the various sizes was calculated from the measurements. There appear to be resonances at certain frequencies in th...
متن کاملStatus of Rf Deflecting Cavity Design for the Generation of Short X-ray Pulses in the Advanced Photon Source Storage Ring
The Advanced Photon Source (APS) at Argonne National Laboratory is exploring the possibility of using radio frequency deflection to generate x-ray radiation pulses on the order of 1 pico-second (Delta t – 70%) or less [1]. This scheme is based on a proposal by A. Zholents et al. [2] that relies on manipulating the transverse momentum of the electrons in a bunch by using an rf deflecting cavity ...
متن کاملاثر Action Potential Simulation Therapy در کاهش درد بیماران با مشکلات عضلانی اسکلتی در بیماران
Introduction: Musculoskeletal problems are the common complaints of patients refer to internal medicine clinics and the pain is the most important of them. There are different physiotherapy methods for reduction of pain and action potential simulation therapy (APS therapy) is one of newest methods. The aim of this study was to determine reduction of pain with APS therapy. Materials & Method...
متن کاملQuality Factor Enhancement of Optical Channel Drop Filters Based on Photonic Crystal Ring Resonators
In this paper, a channel drop ring resonator filter based on two dimensional photonic crystal is proposed which is suitable for all optical communication systems. The multilayer of silicon rods in the center of resonant ring enables one to adjust resonant wavelength of the ring and enhance power coupling efficiency between ring and waveguide. Refractive index and radius of multilayer rods insid...
متن کامل