A5033059702- Particle Accelerators and Free-Electron Lasers
- Particle accelerators and beam dynamics
- Superconducting Materials and Applications
- Particle Detector Development and Performance
- Gyrotron and Vacuum Electronics Research
- Particle physics theoretical and experimental studies
- Magnetic confinement fusion research
- Electron and X-Ray Spectroscopy Techniques
- Plasma Diagnostics and Applications
- Quantum Chromodynamics and Particle Interactions
- High-Energy Particle Collisions Research
- Distributed and Parallel Computing Systems
- Atomic and Molecular Physics
- Advanced Data Storage Technologies
- Atomic and Subatomic Physics Research
- Laser-Plasma Interactions and Diagnostics
- Muon and positron interactions and applications
- X-ray Spectroscopy and Fluorescence Analysis
- Radiation Detection and Scintillator Technologies
- Black Holes and Theoretical Physics
- Nuclear Physics and Applications
- Photocathodes and Microchannel Plates
- Scientific Computing and Data Management
- Nuclear reactor physics and engineering
- Antenna Design and Optimization
Adam Mickiewicz University in Poznań
2023
Lawrence Berkeley National Laboratory
2004-2014
University of California, Berkeley
1978-2014
Cornell University
2013
Brookhaven National Laboratory
2003-2007
Stanford Synchrotron Radiation Lightsource
1992-2007
SLAC National Accelerator Laboratory
1992-2007
Los Alamos National Security (United States)
2006
Menlo School
2003
Fusion Academy
2002
We provide a detailed description of model and its computational algorithm for the secondary electron emission process. The is based on broad phenomenological fit to data secondary-emission yield emitted-energy spectrum. two sets values parameters by fitting our particular sets, one copper other stainless steel.
Present and future accelerators' performances may be limited by the electron cloud (EC) effect. The EC formation evolution are determined wall-surface properties of accelerator vacuum chamber. We present measurements total secondary yield (SEY) related energy distribution curves electrons as a function incident-electron energy. Particular attention has been paid to emission process due very low-energy primary ($<20\text{ }\text{ }\mathrm{e}\mathrm{V}$). It is shown that SEY approaches unity...
The BaBar detector operated successfully at the PEP-II asymmetric e+e− collider SLAC National Accelerator Laboratory from 1999 to 2008. This report covers upgrades, operation, and performance of systems, as well trigger, online offline computing, aspects event reconstruction since beginning data taking.
We have applied our simulation code POSINST to evaluate the contribution growth rate of electron cloud instability in proton storage rings. In particular, we present here recent results for main features ring Spallation Neutron Source at Oak Ridge, and updated Proton Storage Ring Los Alamos. A key ingredient model is a detailed description secondary emission process, including refined emitted energy spectrum, three components yield, namely, true secondary, rediffused backscattered components.
We present a brief summary of various aspects the electron-cloud effect (ECE) in accelerators. For further details, reader is encouraged to refer proceedings many prior workshops, either dedicated EC or with significant contents, including entire "ECLOUD" series [122]. In addition, flavors Particle Accelerator Conferences [23] contain large number EC-related publications. The ICFA Beam Dynamics Newsletter [24] contains one issue, and several occasional articles, on EC. An extensive reference...
Electron cloud instabilities in the Los Alamos Proton Storage Ring and those foreseen for Oak Ridge Spallation Neutron Source are examined theoretically, numerically, experimentally.16 MoreReceived 16 October 2002DOI:https://doi.org/10.1103/PhysRevSTAB.6.014203This article is available under terms of Creative Commons Attribution 3.0 License. Further distribution this work must maintain attribution to author(s) published article’s title, journal citation, DOI.
Electron effects in the High Current Experiment (HCX) are studied via computer simulation. An approximate expression for secondary electron yield a potassium ion striking stainless steel is derived and compared with experimental results. This has peak of roughly 55 electrons at normal incidence an energy 60 MeV. Using empirical angular dependence, combined numerical simulation HCX beam dynamics to obtain estimate number expected per ion-wall collision HCX. that approximately 150--200 may result
It was shown recently that it may be computationally advantageous to perform computer simulations in a Lorentz boosted frame for certain class of systems. However, even if the model relies on covariant set equations, pointed out algorithmic difficulties related discretization errors have overcome order take full advantage potential speedup. In this paper, we summarize findings, and their solutions, review applications technique been performed date.
As a result of the synchrotron radiation from positively-charged beam, an electron cloud is expected to develop in vacuum chamber combined effects photoelectric and secondary emission processes. We provide here first estimate electron-cloud effect on individual particles beam. focus space-charge tune spread, distortion beta function dispersion, synchro-betatron coupling. illustrate with numerical applications PEP-II positron ring. conclude that magnitude not negligible, although it large...
We present an understanding of the effect various features secondary emission yield (SEY) and spectrum on formation dissipation electron cloud (EC). This is based dedicated experimental studies at several storage rings systematic benchmarks simulations against these measurements.
We have augmented the code POSINST to include solenoid fields and used it simulate buildup of electron cloud due in PEP-II positron ring. find that distribution electrons is strongly affected by resonances associated with cyclotron period bunch spacing. In addition, we discover a threshold beyond which density grows exponentially until reaches space charge limit. The does not depend on spacing but population.
Accelerators for heavy-ion inertial fusion energy (HIF) have an economic incentive to fit beam tubes tightly beams, putting them at risk from electron clouds produced by emission of electrons and gas walls. Theory PIC simulations suggest that the will be radially trapped in /spl ges/1 kV ion-beam potential. We are beginning studies on High-Current Experiment (HCX) with unique capabilities characterize production trapping, effects ion mitigation techniques. measuring flux evolved a target,...
Electron clouds and gas pressure rise limit the performance of many major accelerators. A multi-laboratory effort to understand underlying physics via combined application experiment, theory, simulation is underway. We present here status capability development, based on a merge three-dimensional parallel Particle-In-Cell (PIC) accelerator code WARP electron cloud POSINST, with additional functionalities. The development new follows "roadmap" describing different functional modules, their...