A5055671365- Particle accelerators and beam dynamics
- Particle Accelerators and Free-Electron Lasers
- Superconducting Materials and Applications
- Gyrotron and Vacuum Electronics Research
- Magnetic confinement fusion research
- Laser-Plasma Interactions and Diagnostics
- Particle Detector Development and Performance
- Atomic and Molecular Physics
- Electron and X-Ray Spectroscopy Techniques
- Classical Philosophy and Thought
- Advancements in Photolithography Techniques
- Plasma Diagnostics and Applications
- Ionosphere and magnetosphere dynamics
- Pulsed Power Technology Applications
- Solar and Space Plasma Dynamics
- Ion-surface interactions and analysis
- Astrophysics and Cosmic Phenomena
- Cold Atom Physics and Bose-Einstein Condensates
- Mechanical and Optical Resonators
- Numerical methods for differential equations
- Photocathodes and Microchannel Plates
- Lightning and Electromagnetic Phenomena
- Lignin and Wood Chemistry
- Muon and positron interactions and applications
- Fusion materials and technologies
Fermi National Accelerator Laboratory
2015-2024
European Organization for Nuclear Research
2019
University of Chicago
2017
Ivanovo State University of Chemistry and Technology
2016
Fermi Research Alliance
1999-2016
Schlumberger (British Virgin Islands)
2012
University of California, Riverside
2007
Oak Ridge National Laboratory
2003
Budker Institute of Nuclear Physics
1996-2002
Ivanovo State University
2002
We report on an experimental demonstration of electron cooling high-energy antiprotons circulating in a storage ring. In our experiments, cooling, well-established method at low energies ($<500\text{ }\text{ }\mathrm{MeV}/\mathrm{\text{nucleon}}$), was carried out new region beam parameters, requiring multi-MeV dc and unusual transport line. this Letter, we present the results longitudinal force measurements compare them with theoretical predictions.
Beam instabilities cover a wide range of effects in particle accelerators and they have been the subjects intense research for several decades. As machines performance was pushed new mechanisms were revealed nowadays challenge consists studying interplays between all these intricate phenomena, as it is very often not possible to treat different separately. The aim this paper review main mechanisms, discussing particular recent developments beam instability theories simulations.
The head-tail modes are described for the space charge tune shift significantly exceeding synchrotron tune. A general equation is derived. spatial shapes of modes, their frequencies, and coherent growth rates explored. Landau damping also found. suppression transverse mode coupling instability by explained.
Nested head-tail is a Vlasov solver for transverse oscillations in multibunch beams. It takes into account azimuthal, radial, coupled-bunch, and beam-beam degrees of freedom affected by arbitrary dipole wakes, feedback damper,beam-beam effects Landau damping.
In conventional low energy electron coolers, the beam is immersed in a continuous solenoid, which provides calm and tightly focused cooling section. While suitable for energies, continuity of accompanying magnetic field hardly realizable at relativistic energies. We consider possibility using an extended solenoid gun section only, applying lumped focusing rest transport line.
In the optics of charged particle beams, circular transverse modes can be introduced; they provide an adequate basis for rotation-invariant transformations. A group these transformations is shown to identical a canonical angular momentum preserving mappings. These mappings and are parametrized similar Courant-Snyder forms conventional uncoupled, or planar, case. The planar-to-circular reverse transformers (beam adapters) introduced in terms planar modes; their implementation on skew...
Modern and future particle accelerators employ increasingly higher intensity brighter beams of charged particles become operationally limited by coherent beam instabilities. Usual methods to control the instabilities, such as octupole magnets, feedback dampers use chromatic effects, less effective insufficient. We show that, in contrast, Lorentz forces a low-energy, magnetically stabilized electron beam, or "electron lens", easily introduces transverse nonlinear focusing sufficient for...
Transverse beam stability is strongly affected by the space charge. Usually it analyzed with rigid-beam model. However, this model only valid when a bare (not charge) tune spread small compared to charge shift. This condition specifies relatively area of parameters which, however, most interesting for practical applications. The Landau damping rate and Schottky spectra are computed assuming that validity satisfied. results applied round Gaussian beam. thresholds described simple fits cases...
The wake forces produced by a beam bunch can be reduced making the vacuum chamber cross section axially asymmetric. Furthermore, asymmetry results in betatron tune shift for particles tail of bunch. As result, transverse instabilities should significantly suppressed an asymmetric chamber.
Transverse dipole modes in bunches with space charge are simulated using the synergia accelerator modeling package and analyzed dynamic mode decomposition. The properties of first three modes, including their shape, damping rates, tune shifts described over entire range strength. intrinsic Landau predicted estimated 2009 by one authors is confirmed a reasonable scaling factor $\ensuremath{\simeq}2.4$. For KV distribution, very good agreement PATRIC simulations performed Kornilov...
Plasma wakefield acceleration is one of the main technologies being developed for future high-energy colliders. Potentially, it can create a cost-effective path to highest possible energies ${e}^{+}{e}^{\ensuremath{-}}$ or $\ensuremath{\gamma}\ensuremath{-}\ensuremath{\gamma}$ colliders and produce profound effect on developments physics. Acceleration in blowout regime, where all plasma electrons are swept away from axis, presently considered be primary choice beam acceleration. In this...
For a single hadron bunch in circular accelerator at zero chromaticity, without multi-turn wakes and electron clouds other beams, only one transverse collective instability is possible, the mode-coupling instability, or TMCI. sufficiently strong space charge (SC), threshold of wake-driven coherent tune shift normally increases linearly with SC shift, as independently concluded by several authors using different methods. This stability condition has, however, very strange feature: SC, it...
We report progress on the R&D program for electron-cooling of Relativistic Heavy Ion Collider (RHIC). This electron cooler is designed to cool 100 GeV/nucleon at storage energy using 54 MeV electrons. The source will be a superconducting RF photocathode gun. accelerator recovery linac. frequency set 703.75 MHz. maximum bunch 9.38 MHz, with charge 20 nC. has following components: photoinjector and its photocathode, linac cavity, start-to-end beam dynamics magnetized electrons, cooling...
Particle acceleration in plasma creates a possibility of exceptionally high accelerating gradients and appears to be very attractive option for future linear electron–positron and/or [Formula: see text]–[Formula: text] colliders. These have already been demonstrated number experiments. However, collider requires beam brightness which still needs demonstrated. In this article we discuss major phenomena limit the accelerated and, consequently, luminosity.
Conditions for existence, uniqueness and stability of bunch steady states are considered. For the existence problem, simple algebraic equations derived, showing result both action Hamiltonian domain distributions. van Kampen theory is used. Emerging discrete modes show either loss Landau damping, or instability. This method can be applied an arbitrary impedance, RF shape beam distribution function Available areas on intensity-emittance plane shown resistive wall wake single harmonic,...
Which gain and phase have to be set for a bunch-by-bunch transverse damper, at which chromaticity it is better stay? These questions are considered three models: the two-particle model with possible quadrupole wake, author's Nested Head-Tail Vlasov solver broadband impedance, same LHC impedance model.
The physics interest in a luminosity upgrade of RHIC requires the development cooling-frontier facility. Detailed calculations were made electron cooling stored beams. This has been followed by beam dynamics simulations to establish feasibility creating necessary beam. accelerator will be superconducting Energy Recovery Linac (ERL). An intensive experimental R&D program engages various elements accelerator, as described 24 contributions 2007 PAC.
Van Kampen modes are eigen-modes of Jeans-Vlasov equation. Their spectrum consists continuous and, possibly, discrete parts. Onset a van mode means emergence coherent without any Landau damping; thus, even tiny couple-bunch wake is sufficient to drive instability. Longitudinal instabilities observed at Tevatron, RHIC and SPS can be explained as loss damping (LLD), which shown here happen fairly low impedances. For repulsive wakes single-harmonic RF, LLD found extremely sensitive steepness...