A5020545730- Particle Accelerators and Free-Electron Lasers
- Particle accelerators and beam dynamics
- Superconducting Materials and Applications
- Magnetic confinement fusion research
- Physics of Superconductivity and Magnetism
- Quantum Chromodynamics and Particle Interactions
- Particle physics theoretical and experimental studies
- High-Energy Particle Collisions Research
- Laser-Plasma Interactions and Diagnostics
- Advanced X-ray Imaging Techniques
- Crystallography and Radiation Phenomena
- Magnetic Properties and Applications
- HVDC Systems and Fault Protection
- Atomic and Molecular Physics
- Metal Forming Simulation Techniques
- Muon and positron interactions and applications
- Particle Detector Development and Performance
- Pulsed Power Technology Applications
- Cold Atom Physics and Bose-Einstein Condensates
- Laser and Thermal Forming Techniques
- Advanced Radiotherapy Techniques
- X-ray Spectroscopy and Fluorescence Analysis
- Advanced Surface Polishing Techniques
- Advancements in Photolithography Techniques
- Advanced Electron Microscopy Techniques and Applications
Argonne National Laboratory
1989-2024
Seoul National University
2023-2024
Ulsan National Institute of Science and Technology
2018-2023
European Organization for Nuclear Research
2021-2023
SLAC National Accelerator Laboratory
2023
High energy particle accelerators have been crucial in providing a deeper understanding of fundamental particles and the forces that govern their interactions. In order to increase or reduce size accelerator, new acceleration schemes need be developed. Plasma wakefield acceleration, which electrons plasma are excited, leading strong electric fields, is one such promising novel technique. Pioneering experiments shown an intense laser pulse electron bunch traversing plasma, drives fields 10s...
Characterizing the phase space distribution of particle beams in accelerators is a central part understanding beam dynamics and improving accelerator performance. However, conventional analysis methods either use simplifying assumptions or require specialized diagnostics to infer high-dimensional (>2D) properties. In this Letter, we introduce general-purpose algorithm that combines neural networks with differentiable tracking efficiently reconstruct distributions without using manipulations....
Beams with cross-plane coupling or extreme asymmetries between the two transverse phase spaces are often encountered in particle accelerators. Flat beams large transverse-emittance ratios critical for future linear colliders. Similarly, magnetized significant expected to enhance performance of electron cooling hadron beams. Preparing these requires precise control and characterization four-dimensional space. In this study, we employ generative phase-space reconstruction techniques rapidly...
We use a relativistic ionization front to provide various initial transverse wakefield amplitudes for the self-modulation of long proton bunch in plasma. show experimentally that, with sufficient amplitude [$\ensuremath{\ge}(4.1\ifmmode\pm\else\textpm\fi{}0.4)\text{ }\text{ }\mathrm{MV}/\mathrm{m}$], phase modulation along is reproducible from event event, 3%--7% (of $2\ensuremath{\pi}$) rms variations all bunch. The not lower amplitudes. observe transition between these two regimes. Phase...
A 3.3-cm period Nd-Fe-B hybrid undulator has been designed and successfully operated in the Cornell Electron Storage Ring (CESR). This 2-m-long, 123-pole insertion device is a prototype of one undulators planned for Advanced Photon Source. In dedicated operation, produced expected brightness at 5.437 GeV with fundamental x-ray energy ranging from 4.3 to 7.9 keV corresponding change gap 1.5 2.8 cm.
We report the development of a multileaf collimator (MLC) for charged particle beams, based on independently actuated tungsten strips that can selectively scatter unwanted particles. The MLC is used in conjunction with an emittance exchange beamline to rapidly generate highly variable longitudinal bunch profiles. developed consists 40 independent leaves are 2 mm wide and move up 10 operates ultrahigh vacuum environment, enabled by novel features such as magnetically coupled actuation. An...
Self-modulation is a beam–plasma instability that useful to drive large-amplitude wakefields with bunches much longer than the plasma skin depth. We present experimental results showing that, when increasing ratio between initial transverse size of bunch and depth, occurs later along bunch, or not at all, over fixed length because amplitude decreases. show cases for which self-modulation does develop, we introduce simple model discussing conditions it would occur after any length. Changing...
We have measured the spectrum of light hadrons ($\ensuremath{\pi}$, $\ensuremath{\rho}$, ${a}_{1}$, ${b}_{1}$, $\frac{{f}_{0}}{{a}_{0}}$, $N$, and $\ensuremath{\Delta}$) in quenched approximation to lattice QCD on a ${32}^{3}$ \ifmmode\times\else\texttimes\fi{} 64 at $\ensuremath{\beta}=\frac{6}{{g}^{2}}=6.5$. For these measurements we used staggered quark propagators from two different wall sources. The masses were ${m}_{q}=0.01$, ${m}_{q}=0.005$, ${m}_{q}=0.025$ (lattice units), allowing...
We present the first direct evidence that quenched QCD differs from full in chiral (${\mathit{m}}_{\mathit{q}}$\ensuremath{\rightarrow}0) limit, as predicted by perturbation theory, our lattice simulations at \ensuremath{\beta}=6/${\mathit{g}}^{2}$=6.0. measure spectrum of light hadrons on ${16}^{3}$\ifmmode\times\else\texttimes\fi{}64, ${24}^{3}$\ifmmode\times\else\texttimes\fi{}64, and ${32}^{3}$\ifmmode\times\else\texttimes\fi{}64 lattices, using staggered quarks masses...
A facility for investigating the effects of cyclic strains on current-voltage relation (I-V plots) in a superconducting composite has been constructed, as part conductor test program directed by Oak Ridge National Laboratory Tokamak Experimental Power Reactor. The initial results ribbon containing 18 Nb-Ti twisted filaments copper showed three effects: (1) 3% decrease I <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">c</inf> at 40 kOe during 200...
The Advanced Photon Source (APS) 7-GeV positron storage ring at Argonne National Laboratory (ANL) produces high brilliance bending magnet and insertion device X-rays for up to 70 X-ray beamlines. To efficiently make use of the ring's brilliance, an extremely tight tolerance has been placed on beam stability, namely that be stable a level which is less than 5% its rms size. This requirement amounts /spl plusmn/4.4 microns in vertical plane plusmn/17 horizontally, assuming 10% coupling. While...
Using finite size scaling and histogram methods we obtain results from lattice simulations indicating the logarithmic triviality of scalar quantum electrodynamics, even if bare gauge coupling is large. Simulations noncompact formulation Abelian Higgs model with fixed length fields on ${L}^{4}$ lattices $L$ ranging 6 through 20 indicate a line second-order critical points. Lengthy runs for each produce specific-heat peaks which grow logarithmically whose couplings shift picking out...
Construction of a single-pass free-electron laser (FEL) based on the self-amplified spontaneous emission (SASE) mode operation is nearing completion at Advanced Photon Source (APS) with initial experiments imminent. The APS SASE FEL proof-of-principle fourth-generation light source. As January 1999 undulator hall, end-station building, necessary transfer lines, electron and optical diagnostics, injectors, undulators have been constructed and, exception undulators, installed. All preliminary...
Magnetized beams beam with significant canonical angular momentum are critical to electron cooling of hadron such as contemplated in next-generation and electron-ion colliders. The transport magnetized over long distances a locally non-axisymmetric external field is challenging. An alternative transform the into an uncoupled "flat beam", produced "flat" distance, reintroduce cross-plane coupling "re-magnetize" beam. In this paper, we demonstrate via numerical simulation laboratory...
An active plasma lens (APL) focuses the beam in both horizontal and vertical planes simultaneously using a magnetic field generated by discharge current through plasma. A size of $5--10\text{ }\text{ }\ensuremath{\mu}\mathrm{m}$ can be achieved within short distance focusing gradient on order $100\text{ }\mathrm{T}/\mathrm{m}$. The APL is therefore an attractive element for wakefield acceleration, because ultrasmall witness electron required injection into to minimize emittance growth...
An undulator of period 1 mm has been designed as part a series studies toward table-top synchrotron radiation sources. The consists silver conductor embedded in poles and substrate nickel-iron. Computations predict field pattern appropriate strength quality if the current can be prevented from shunting across nickel-iron poles, either through insulation or slotted poles. A ten-scale model fabricated measured; full-scale also constructed by conventional machining techniques, but not yet measured.
A split-pair superconducting coil of the Pulsed Cable Test Facility (PCTF) at Argonne National Laboratory (ANL) has been successfully tested both in dc and pulsing modes. At a peak operating current 11 kA, magnetic field stored energy are 6.5 T 3.3 MJ, respectively. In test, was charged to 10.55 kA 1.0 s discharged zero 1.6 s. The ac losses this mode were 7.5 kJ/pulse. is composed two solenoids each with 22 layers 9.14 turns per layer. cable for consists 24, 19-strand NbTi subcables....
The status of the design and fabrication a prototype sector storage ring vacuum system for Advanced Photon Source (APS) is described. 26.5-m-long assembled within full-scale magnet tunnel mockup to study interspatial component relationships maintenance, as well operational performance. Each completed section mounted an integral part modular structure that contains magnets power supplies on common base. Unique automatic machine welding designs techniques are employed in aluminum chambers from...
Coherent synchrotron radiation (CSR) is a collective effect that mainly occurs when the trajectory of an electron beam bent in dipole magnet. It affects by distorting phase space along its slice distribution, which leads to emittance growth. Therefore, CSR should be suppressed transport beams without further degradation emittance. In linear optics, CSR-induced can controlling Twiss parameters electron-beam transfer line. However, owing some physical constraints, transfer-line optics may...