A5035871988- Particle Accelerators and Free-Electron Lasers
- Particle accelerators and beam dynamics
- Superconducting Materials and Applications
- Gyrotron and Vacuum Electronics Research
- Magnetic confinement fusion research
- Particle Detector Development and Performance
- Particle physics theoretical and experimental studies
- Laser-Plasma Interactions and Diagnostics
- Muon and positron interactions and applications
- Quantum optics and atomic interactions
- Electromagnetic Compatibility and Measurements
- Mechanical and Optical Resonators
- Atomic and Subatomic Physics Research
- Scientific Research and Discoveries
- Plasma Diagnostics and Applications
- Electron Spin Resonance Studies
- Neutrino Physics Research
- Crystallography and Radiation Phenomena
- Structural Analysis and Optimization
- Electron and X-Ray Spectroscopy Techniques
- X-ray Spectroscopy and Fluorescence Analysis
- Scientific Computing and Data Management
- Structural Load-Bearing Analysis
- Cold Atom Physics and Bose-Einstein Condensates
- Astrophysics and Cosmic Phenomena
GSI Helmholtz Centre for Heavy Ion Research
2011-2024
European Organization for Nuclear Research
2005-2023
Goethe University Frankfurt
2017-2023
University of Bologna
1998-1999
Istituto Nazionale di Fisica Nucleare, Sezione di Bologna
1998-1999
Optics measurements at the LHC are mainly based on turn-by-turn signal from hundreds of beam position monitors (BPMs). Faulty BPMs produce erroneous causing unreliable computation optics functions. Therefore, detection faulty prior to is crucial for adequate analysis. Most faults can be removed by applying traditional cleaning techniques. However, functions reconstructed cleaned data systematically exhibit a few nonphysical values which indicate presence remaining BPMs. A novel method...
The theory and simulation of coherent resonant coupling due to space charge in coasting or bunched anisotropic equilibrium beams is presented. Our work confirms that analytical results on oscillations instabilities KV (Kapchinskij-Vladimirskij) distributions are a valid tool interpret the findings from 2D 3D self-consistent particle-in-cell simulations for both waterbag distributions. With reference rings we discuss tune shifts up fourth order introduce coupled mode coefficient, which...
The combined effect of space charge and nonlinear resonance on beam loss emittance was measured in a benchmarking experiment over 1.2 s long flat bottom at 1.4 GeV kinetic energy the presence single controllable octupole. By lowering working point towards resonance, gradual transition from loss-free core blowup to regime dominated by continuous found. We compare observation with 3D simulations based new analytical model obtain good agreement regime. Our explanation is terms synchrotron...
It is discovered that, for a high intensity beam, the $4\ensuremath{\sigma}=360\ifmmode^\circ\else\textdegree\fi{}$ (or $4\ensuremath{\nu}=1$) resonance of linear accelerator manifested through octupolar term space charge potential when depressed phase advance per cell $\ensuremath{\sigma}$ close to and below 90\ifmmode^\circ\else\textdegree\fi{} but no effect observed just above 90\ifmmode^\circ\else\textdegree\fi{}. To verify that this resonance, frequency analysis performed study crossing...
Trapping of particles in nonlinear resonances the presence space charge and synchrotron motion may be a source beam halo generation loss high intensity synchrotrons, particular for extended storage times at injection plateau as planned SIS100 FAIR project. Although extensive simulation studies have theoretically demonstrated this mechanism, experimental evidence was so far limited to demonstration experiments CERN Proton Synchrotron (PS) 2002--2003 using an octupolar resonance. Here we...
Abstract Magnetic field errors and misalignments cause optics perturbations, which can lead to machine safety issues performance degradation. The correlation between magnetic deviations of the measured functions from design be used in order build supervised learning models able predict directly a selection observables. Extending knowledge individual magnets offers potential improvements beam control by including this information into corrections computation. Besides, we also present...
Electron clouds in the beam pipe of high-energy proton or positron storage rings can give rise to significant incoherent emittance growth, at densities far below coherent-instability threshold. We identify two responsible mechanisms: namely, (1) a particle periodically crosses resonance and (2) region bunch where its motion is linearly unstable. Formation halo beam-core blow up, respectively, are result. Key ingredients for both processes synchrotron electron-induced tune shift. The...
The effect of space charge on bunched beams has been the subject numerous numerical and experimental studies in first decade 2000. Experimental campaigns performed at CERN Proton Synchrotron 2002 GSI SIS18 2008 confirmed existence an underlying mechanism beam dynamics periodic resonance crossing induced by synchrotron motion charge. In this article we present extension previous to describe a controlled coupled (2D) third order resonance. simulation results latest campaign shed new light...
The Neutrino Factory is a new concept for an accelerator that produces high-intensity, high-energy beam of electron and muon neutrinos – the ultimate tool neutrino oscillation studies only machine conceived up today could help detect CP violation leptons. basic production from decay muons. Due to their short lifetime, these muons have be accelerated very fast. Several techniques, like high-intenstiy proton linac, high-power targets, ionization cooling or recirculating linacs are required....
We study emittance growth for transport of uniform and Gaussian beams particles in rf cavities solenoids show analytically its dependence on initial beam parameters. Analytical results are confirmed with simulation studies over a broad range different beams.
Abstract Radio Frequency Knock Out (RF KO) extraction is used to extract stored particle beams from synchrotrons through transverse excitation, delivering spills of particles for experiments and medical therapy. Minimizing the fluctuations spill intensity vital prevent detector pile-up interlocks while making most efficient use extracted beam. To improve quality, different excitation signals with characteristic frequency spectra are explored. Results experimental studies at Heidelberg Ion...
Abstract The motion of systems with linear restoring forces and recurring nonlinear perturbations is central importance in physics. When a system’s natural oscillation frequencies the frequency satisfy certain algebraic relations, dynamics become resonant. In accelerator physics, an understanding resonances crucial for avoiding loss beam particles. Here we confirm theoretical prediction single two-dimensional coupled resonance by observing so-called fixed lines. Specifically, use CERN Super...
New developments in accelerator physics have broadened the set of available techniques for manipulating charged-particle beams. Adiabatic trapping and transport a beam resonance islands has been studied successfully implemented at CERN Proton Synchrotron to perform multiturn extraction. Bent crystals installed Large Hadron Collider, improving cleaning performance collimation system, Super reducing losses extraction septum case slow In this Letter, we discuss potential combined use bent...
Systematic space-charge resonances are found to cause substantial emittance growth in proton driver rings and non-scaling fixed field alternating gradient (FFAG) accelerators. To avoid systematic nonlinear resonances, the phase advance of each cell must π/2 π/3. This limits betatron tune range momentum acceptance for FFAG The factor (EGF), defined as ratio final initial emittance, is obey scaling properties linear shift parameter, ramping rate, stop-band widths random quadrupole...
Particle-in-cell (PIC) is the most used algorithm to perform self-consistent tracking of intense charged particle beams. It based on depositing macro-particles a grid, and subsequently solving it Poisson equation. well known that PIC algorithms occupy intrinsic limitations as they introduce numerical noise. Although not significant for short-term tracking, this becomes important in simulations circular machines over millions turns may induce artificial diffusion beam. In work, we present...
We study halo emittance growth in anisotropic beams and show that the rms resulting from mismatch is highly anisotropic, depending on tune ratio. find free-energy limit calculated by Reiser [J. Appl. Phys. 70, 1919 (1991)] for an axisymmetric 1D can be extended to 2D if understood as upper bound averaged per degree of freedom. The thus-obtained ``free-energy limit'' ideal transport system compared with simulations Spallation Neutron Source linac.
Trapping by resonances or scattering off induced space charge (SC) electron cloud (EC) in conjunction with synchrotron motion can explain observations of slow beam loss and emittance growth, which are often accompanied changes the longitudinal profile. In this paper we review recent progress understanding modeling underlying mechanisms, highlight differences similarities between cloud, discuss simulation results light experimental observations, e.g., at GSI, CERN, BNL. particular, address...
The origin of nonlinear dynamics traces back to the study planets with seminal work Poincaré at end nineteenth century: Les Méthodes Nouvelles de la Mécanique Céleste, Vols. 1-3 (Gauthier Villars, Paris, 1899). In his he introduced a methodology fruitful for investigating dynamical properties complex systems, which led so-called "Poincaré surface section," allows one capture global system, characterized by fixed points and separatrices respect regular chaotic motion. For two-dimensional...
We show that pronounced collective nonlinear behavior is present in a beam with linear coupling and space charge as described by the complete second order moment equations. The effects result shifted broadened resonance condition well saturation emittance transfer. For slow stop-band crossing either evolves along skewed matched solution full exchange or hindered effects, depending on ratio direction of crossing.
In this paper we present a comprehensive analysis of the self-consistent, collective behavior associated with space-charge-driven (Montague) coupling resonance near $2{Q}_{x}\ensuremath{-}2{Q}_{y}=0$, including effect linear coupling. Based on analytical work and particle-in-cell simulation in 2D coasting beam limit, derive scaling laws for stop-band widths growth rates, which may be applied to circular machines as well accelerators. For slow crossing stop bands, find strong directional...