Measuring and optimizing the momentum aperture in a particle accelerator (original) (raw)
Related papers
Measuring and Understanding the Momentum Aperture in a Storage Ring
Proceedings of the 2005 Particle Accelerator Conference, 2005
The momentum aperture of a storage ring is a very important parameter that strongly influences the performance, especially the beam lifetime. For the special case of synchrotron light sources with small emittance like the Advanced Light Source (ALS), the momentum aperture depends strongly on the transverse dynamics. It is very sensitive to machine conditions such as the tunes, chromaticities, lattice symmetry, and spurious coupling, since depending on those conditions the Touschek scattered particles explore different resonance regions in the phase space. In light sources, the momentum aperture usually also depends strongly on the vertical physical aperture. Applying frequency analysis techniques in simulations and for turnby-turn orbit measurement data provides a very powerful tool to measure and understand limitations of the dynamic momentum aperture. The techniques presented are applicable to other light sources, as well as damping rings and many types of colliders.
Understanding the dynamic momentum aperture of the Advanced Light Source
PACS2001. Proceedings of the 2001 Particle Accelerator Conference (Cat. No.01CH37268), 2001
The lifetime of a light source with small emittance like the Advanced Light Source (ALS) is usually limited by the momentum acceptance of the ring. Large momentum acceptances are reached by providing enough RF voltage and by avoiding a degradation of the dynamic momentum aperture. At the ALS the size of the momentum acceptance depends strongly on the transverse dynamics. It is very sensitive to machine conditions such as the tunes and chromaticities since depending on those conditions the Touschek scattered particles explore different resonance regions in the phase space. In this paper we show that by using a single-turn 'pinger' magnet together with turn-byturn beam position monitors (BPM) one can identify the cause of a reduction in momentum acceptance and take steps to improve the acceptance.
Application of Direct Methods of Optimizing Storage Ring Dynamic and Momentum Apertures
accelconf.web.cern.ch
Optimization of dynamic and momentum apertures is one of the most challenging problems in storage ring design. For storage-ring-based x-ray sources, large dynamic aperture is important in obtaining high injection efficiency, which leads to efficient operation and protects components from radiation damage. X-ray sources require large momentum aperture to obtain sufficiently long Touschek lifetimes with low-emittance beams. We have developed effective methods of optimizing dynamic and momentum apertures that rely directly on tracking using a moderately sized Linux cluster. After reviewing the method, we describe examples of its application to APS operations, upgrades, and next-generation storage rings.
In high chromaticity circular accelerators, rapid decoherence of the betatron motion of a particle beam can make the measurement of lattice and bunch values, such as Courant-Snyder parameters and betatron amplitude, difficult. A method for reconstructing the momentum distribution of a beam from beam position measurements is presented. Further analysis of the same beam position monitor data allows estimates to be made of the Courant-Snyder parameters and the amplitude of coherent betatron oscillation of the beam. The methods are tested through application to data taken on the linear nonscaling fixed field alternating gradient accelerator, EMMA.
AIP Conference Proceedings, 2003
Higher energies and higher intensities are the necessary conditions for the success of future accelerators. Higher energies need stronger external electromagnetic fields to guide, focus, and accelerate charged particles, while higher intensities result in source of intense selffields. In both cases, particle motion deviates considerably from a plain linear evolution as described by the classical Hill equation of transverse betatron motion. Particle stability becomes an issue: this problem can be properly tackled using tools from the nonlinear theory of dynamical systems. The concept of dynamic aperture for single-particle motion will be presented underlying links with the fundamental theorems of classical mechanics, such as KAM and Nekhoroshev theorems. Modern numerical techniques to compute the dynamic aperture will be discussed with special emphasis on accuracy analysis. Finally, measurements of particle stability in existing circular accelerators will be reviewed.
Longitudinal Beam Dynamics and Coherent Synchrotron Radiation at cSTART
2021
The compact STorage ring for Accelerator Research and Technology (cSTART) project aims to store electron bunches of LWFA-like beams in a very large momentum acceptance storage ring. The project will be realized at the Karlsruhe Institute of Technology (KIT, Germany). Initially, the Ferninfrarot Linac- Und Test-Experiment (FLUTE), a source of ultra-short bunches, will serve as an injector for cSTART to benchmark and emulate laser-wakefield accelerator-like beams. In a second stage a laser-plasma accelerator will be used as an injector, which is being developed as part of the ATHENA project in collaboration with DESY and Helmholtz Institute Jena (HIJ). With an energy of 50 MeV and damping times of several seconds, the electron beam does not reach equilibrium emittance. Furthermore, the critical frequency of synchrotron radiation is 50 THz and in the same order as the bunch spectrum, which implies that the entire bunch radiates coherently. We perform longitudinal particle tracking simu...
Accelerator and Beam Physics Research Goals and Opportunities
2021
Grand Challenge #2: Beam Quality-"How do we increase the beam phase space density by an order of magnitude, towards the quantum degeneracy limit?" Grand Challenge #3: Beam Control-"How do we measure and control the beam distribution down to the individual particle level?" Grand Challenge #4: Beam Prediction-"How do we develop predictive 'virtual particle accelerators'?"