A5009544695- Particle Accelerators and Free-Electron Lasers
- Particle accelerators and beam dynamics
- Superconducting Materials and Applications
- Magnetic confinement fusion research
- Gyrotron and Vacuum Electronics Research
- Particle Detector Development and Performance
- Advanced X-ray Imaging Techniques
- Photocathodes and Microchannel Plates
- Laser-Plasma Interactions and Diagnostics
- Plasma Diagnostics and Applications
- Laser Design and Applications
- Distributed and Parallel Computing Systems
- Electron and X-Ray Spectroscopy Techniques
- Laser-Matter Interactions and Applications
- Advanced Optical Sensing Technologies
- Scientific Computing and Data Management
- Advanced Data Storage Technologies
- Advancements in Photolithography Techniques
- Medical Imaging Techniques and Applications
- Spacecraft and Cryogenic Technologies
- Metaheuristic Optimization Algorithms Research
- Engineering Applied Research
- Electromagnetic Simulation and Numerical Methods
- Advanced Thermodynamics and Statistical Mechanics
- Cyclone Separators and Fluid Dynamics
Ministry of Education of the People's Republic of China
2025
Northwest University
2025
Lawrence Berkeley National Laboratory
2015-2024
Brookhaven National Laboratory
2015-2024
Changchun Gold Research Institute (China)
2023
Old Dominion University
2021
Michigan State University
2021
China Shipbuilding Industry Corporation (China)
2018
University of California, Berkeley
2006-2016
Xuzhou Children Hospital
2011
In this paper, we present a three-dimensional quasistatic model for high brightness beam dynamics simulation in rf/dc photoinjectors, rf linacs, and similar devices on parallel computers. model, electrostatic space-charge forces within charged particle are calculated self-consistently at each time step by solving the Poisson equation frame then transforming back to laboratory frame. When has large energy spread, it is divided into number of bins or slices so that from contribution bin summed...
Modern scientific datasets present numerous data management and analysis challenges. State-of-the-art index query technologies are critical for facilitating interactive exploration of large datasets, but challenges remain in terms designing a system processing general datasets. The needs to be able run on distributed multi-core platforms, efficiently utilize underlying I/O infrastructure, scale massive
We present results from an experimental study of the beam halo in a high-current 6.7-MeV proton propagating through 52-quadrupole periodic-focusing channel. The gradients first four quadrupoles were independently adjusted to match or mismatch injected beam. Emittances and beamwidths obtained measured profiles for comparisons with maximum emittance-growth predictions free-energy model halo-amplitude particle-core model. support both models theoretical picture formation.
In this paper we report on large-scale high resolution simulations of beam dynamics in electron linacs for the next-generation x-ray free lasers (FELs). We describe key features a parallel macroparticle simulation code including three-dimensional (3D) space-charge effects, short-range structure wakefields, coherent synchrotron radiation (CSR) and treatment radio-frequency (rf) accelerating cavities using maps obtained from axial field profiles. present study microbunching instability causing...
The damaging effect of coherent synchrotron radiation (CSR) on the emittance and energy spread high-energy beams in accelerator light sources can significantly constrain machine design performance. We propose a mitigation approach which dynamical longitudinal component CSR is suppressed by appropriately preparing initial current profile beam. In chicane, linear theory for mechanism CSR-induced growth used to demonstrate how this procedure produce beam whose core experiences transverse...
The shot-noise driven microbunching instability can significantly degrade electron beam quality in x-ray free laser light sources. Experiments were carried out at the Linac Coherent Light Source (LCLS) to study this instability. In paper, we present start-to-end simulations of experiment LCLS using real number electrons. simulation results reproduce measurements quite well. A self-heating mechanism is also illustrated simulation, which helps explain experimental observation.
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...
Abstract C 3 is an opportunity to realize e + - collider for the study of Higgs boson at √ s = 250 GeV, with a well defined upgrade path 550 GeV while staying on same short facility footprint [2,3]. based fundamentally new approach normal conducting linear accelerators that achieves both high gradient and efficiency relatively low cost. Given advanced state designs, key system requires technical maturation main linac. This paper presents staged towards demonstrate technology Direct (source...
The microbunching instability driven by collective effects of the beam inside an accelerator can significantly degrade final electron quality for free laser (FEL) radiation. In this Letter, we propose inexpensive scheme to suppress such in accelerators next generation FEL light sources. Instead using expensive device as a heater or RF deflecting cavities, uses longitudinal mixing associated with transverse spread through bending magnets transport system instability. uncorrelated energy...
Symplectic tracking is important in accelerator beam dynamics simulation. So far, to the best of our knowledge, there no self-consistent symplectic space-charge model available community. In this paper, we present a two-dimensional and three-dimensional multiparticle spectral for This includes both effect from external fields using split-operator method. Such preserves phase space structure shows much less numerical emittance growth than particle-in-cell illustrative examples.
The Large Hadron Collider (LHC) is one of the largest scientific instruments ever built. Since opening up a new energy frontier for exploration in 2010, it has gathered global user community working fundamental particle physics and hadronic matter at extreme temperature density. To sustain extend its discovery potential, LHC will undergo major upgrade 2020s. This increase rate collisions by factor five beyond original design value integrated luminosity ten. configuration, known as High...
In this paper, we explore a method to manipulate low energy electron bunches in space charge dominated regime, and use design linac bunch compressors compress regime. the method, effects instead of avoiding them; i.e., forces generate required chirp ordinary which uses rf accelerating system chirp. We redefine concepts dispersion function beta functions regime guide optimization. Using study (5--22 MeV) compressor produce short ($\ensuremath{\sim}150\text{ }\mathrm{fs}$) small size...
In this paper we present a study of beam halo based on three-dimensional particle-core model an ellipsoidal bunched in constant focusing channel including the effects nonlinear rf focusing. For initially mismatched beam, three linear envelope modes---a high frequency mode, low and quadrupole mode---are identified for azimuthally symmetric beam. The mode has components all phase; transverse phase longitudinal component 180\ifmmode^\circ\else\textdegree\fi{} out no component, two are phase. We...
In this paper we present a new approach, based on shifted Green function, to evaluate the electromagnetic field in simulation of colliding beams. Unlike conventional particle-mesh code, use method which computational mesh covers only largest two This allows us study long-range parasitic collisions accurately and efficiently. We have implemented algorithm parallel strong-strong beam-beam code. As an application, beam sweeping scheme for LBNL luminosity monitor Large Hadron Collider.
We report macroparticle simulations for comparison with measured results from a proton beam halo experiment in 52-quadrupole periodic-focusing channel. An important issue is that the input phase-space distribution not experimentally known. Three different initial distributions shapes predict profiles transport system. Simulations have been fairly successful reproducing core of matched-beam and trend emittance growth as function mismatch factor, but underestimate rate mismatched beams. In...
In recent high luminosity colliders, the finite crossing angle scheme becomes popular to gain with multibunch or long bunch operation. Success of KEKB factory showed that has no problem achieving beam-beam parameters up 0.05. We have studied interactions and without toward higher luminosity. discuss how affects parameter in present using computer simulations. The simulations crab cavities, which realize head-on collision effectively, can be expected double