Searcharxiv⌕ Search

arXiv · physics/0107020

Feedback Systems for Linear Colliders

Abstract

Feedback systems are essential for stable operation of a linear collider, providing a cost-effective method for relaxing tight tolerances. In the Stanford Linear Collider (SLC), feedback controls beam parameters such as trajectory, energy, and intensity throughout the accelerator. A novel dithering optimization system which adjusts final focus parameters to maximize luminosity contributed to achieving record performance in the 1997-98 run. Performance limitations of the steering feedback have been investigated, and improvements have been made. For the Next Linear Collider (NLC), extensive feedback systems are planned as an intregal part of the design. Feedback requiremetns for JLC (the Japanese Linear Collider) are essentially identical to NLC; some of the TESLA requirements are similar but there are significant differences. For NLC, algorithms which incorporate improvements upon the SLC implementation are being prototyped. Specialized systems for the damping rings, rf and interaction point will operate at high bandwidth and fast response. To correct for the motion of individual bunches within a train, both feedforward and feedback systems are planned. SLC experience has shown that feedback systems are an invaluable operational tool for decoupling systems, allowing precision tuning, and providing pulse-to-pulse diagnostics. Feedback systems for the NLC will incorporate the key SLC features and the benefits of advancing technologies.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

L. Hendrickson, P. Grossberg, T. Himel, M. Minty, N. Phinney, P. Raimondi, T. Raubenheimer, H. Shoaee, P. Tenenbaum. 2001-07-10. Feedback Systems for Linear Colliders. https://doi.org/10.1109/pac.1999.795699

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

Phase-Space Shaping due to Betatron Cooling in Wakefield Accelerators and the Onset of the Ion-Channel Laser

Plasma-based accelerators are beginning to employ relativistic beams with unprecedented charge and ultrashort durations. These dense driver beams can drive wakes even in high-density plasmas ($\gtrsim10^{19}$ cm$^{-3}$), where betatron radiation becomes increasingly important and begins to affect the dynamics of the accelerated beam. We show that betatron cooling leads to a strong structuring of the phase space of the beam. This gives rise to bunched, ring-like structures with positive radial position and momentum gradients, \emph{i.e.}, population inversion of the amplitude of oscillation. We derive the characteristic timescales for this process analytically and confirm our predictions with multi-dimensional Particle-in-Cell simulations. The radiation-dominated regime of beam dynamics fundamentally alters the acceleration process and produces self-structured beams\reviewtwo{; Particle-in-Cell simulations of the resulting beams show that it becomes unstable to the ion-channel laser and lead to exponential amplification of radiation.

physics.acc-ph↗

Brilliance: toward autonomous computational research in particle accelerator physics

Computational research in physics requires continuous interplay between simulation and scientific interpretation, demanding substantial specialist effort. Here we introduce Brilliance, a research agent that combines large language models, reusable physics knowledge and numerical simulation to conduct adaptive investigations in accelerator physics. Given a single user prompt, Brilliance designs a fourth-generation synchrotron light source that meets coupled emittance and nonlinear-acceptance requirements. Further exploration yields a design combining sub-10-pm emittance with a large dynamic aperture under realistic engineering constraints, suggesting a route towards hard-X-ray diffraction-limited operation, although the momentum-acceptance target remains unmet. Brilliance also calibrates a model of an operating light source against measured responses, accurately inferring its lattice and calibration errors. Across these studies, Brilliance autonomously revises its computational strategies in response to numerical evidence. These results demonstrate a route towards delegating sustained scientific investigations to agents equipped with domain expertise and numerical tools.

physics.acc-ph↗

Intrabeam scattering of chirped electron bunches with non-Gaussian longitudinal distributions and slice mismatch

Intrabeam scattering (IBS) can significantly increase the uncorrelated energy spread of high-brightness electron bunches in linear accelerators. For chirped bunches transported through beamlines with dispersion, however, the commonly used simulation codes elegant and RF-Track give substantially different predictions. To investigate this discrepancy, a semi-analytical slice model is developed for bunches with non-Gaussian longitudinal distributions and slice-dependent transverse mismatch. The model predicts slice energy-spread evolution in beamlines with dispersion and provides an independent reference for assessing the simulation results. Benchmarks in an achromatic arc show good agreement with RF-Track for both ideal Gaussian and realistic mismatched bunches in the tested cases. The proposed model provides a practical tool for evaluating IBS in linacs beyond the ideal-Gaussian approximation. The comparison also suggests directions for improving the accuracy and efficiency of PIC-based IBS simulations.

physics.acc-ph↗