A5101618488- Particle Accelerators and Free-Electron Lasers
- Particle accelerators and beam dynamics
- Gyrotron and Vacuum Electronics Research
- Superconducting Materials and Applications
- Magnetic confinement fusion research
- Photocathodes and Microchannel Plates
- Plasma Diagnostics and Applications
- Electrostatic Discharge in Electronics
- Laser-Plasma Interactions and Diagnostics
- Particle Detector Development and Performance
- Microwave Engineering and Waveguides
- Energy Harvesting in Wireless Networks
- Photonic and Optical Devices
- High-Energy Particle Collisions Research
- Advanced X-ray Imaging Techniques
- Antenna Design and Analysis
- Physics of Superconductivity and Magnetism
Stony Brook University
2020-2023
Chinese University of Hong Kong
2013-2014
Tatung University
2011
Continuous-wave photoinjectors operating at high accelerating gradients promise to revolutionize many areas of science and applications. They can establish the basis for a new generation monochromatic x-ray free electron lasers, high-brightness hadron beams, or microchip production. In this Letter we report on record-performing superconducting rf gun with ${\mathrm{CsK}}_{2}\mathrm{Sb}$ photocathode. The is generating charge bunches (up $10\text{ }\text{ }\mathrm{nC}/\text{bunch}$) low...
Abstract High brightness, high charge electron beams are critical for a number of advanced accelerator applications. The initial emittance the beam, which is determined by mean transverse energy (MTE) and laser spot size, one most important parameters determining beam quality. bialkali photocathodes illuminated visible have advantages quantum efficiency (QE) low MTE. Furthermore, Superconducting Radio Frequency (SRF) guns can operate in continuous wave (CW) mode at accelerating gradients,...
Solenoids are frequently used for focusing low-energy beams. In this paper, we show how they can serve as multipurpose diagnostics tools to measure various beam parameters, including energy, emittance, the second moments of transverse distribution, and position angle with respect solenoid’s axis. The energy measurement is based on rotation plane motion, opposed generating dispersion a dipole. Measurement trajectory solenoid axis done by analyzing orbit downstream while varying its current....
Microscopic, or short-wavelength, instabilities are known for a drastic reduction of the beam quality and strong amplification noise in beam. Space charge coherent synchrotron radiation to be leading causes such instabilities. In this paper, we present rigorous 3D theory driven by space-charge forces. We define condition when our is applicable an arbitrary accelerator system with coupling. Finally, derive linear integral equation describing instability identify conditions it can reduced...
In this paper we describe a new microbunching instability occurring in charged particle beams propagating along straight trajectory. The nature of these exponentially growing plasma oscillations gave the reason for its name: plasma-cascade instability. Such can strongly amplify longitudinal originating from beam's shot noise, even to point saturation. Resulting random density and energy microstructures drastically reduce beam quality. Conversely, such drive novel high-power sources broadband...
In the aspect of longitudinal beam bunching, bunching strength can be controlled by rf cavity phase and voltage. However, these machine parameters are different from those that interact with itself. order to gain control beam-cavity interaction, calibration must performed. Furthermore, it relies on fitting energy versus a function. Under conventional assumption relativistic conditions, function is first harmonic sinusoidal (a period $2\ensuremath{\pi}$). this expression insufficient for...
This article presents design and measurement of a planar multiband (GSM850/900, DCS, PCS, UMTS bands) antenna used in laptop computer. The can be identified by crossly connecting meandered inverted-F configuration T-shaped monopole. part is mainly responsible for GSM-band operation. To cover the bands, monopole added. Although directly them together, VSWR cannot meet specification at higher band. Therefore, an open-tub added bottom end It investigated that stub serves as capacitive match...
The recently completed second-generation Neutralized Drift Compression eXperiment (NDCX-II) <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1</sup> provides a very tool for the understanding of "warm dense matter" (WDM) as well heavy ion fusion (HIF). latest status NDCX-II is to accelerate 50 nC Li xmlns:xlink="http://www.w3.org/1999/xlink">+</sup> 130 keV and compresses beam with 7 induction cells (accelerating elements). duration will be...
Coherent electron cooling experiment is aimed for demonstration of the proof-of-principle reduction energy spread a single hadron bunch circulating in RHIC. The beam should have required parameters and its orbit be matched to beam. In this paper we present achieved including emittance, spread, other critical indicators. operational issues as well future plans are also discussed.
We present a new type of longitudinal microbunching instability entitled ’Plasma-Cascade Instability’. This could occur in beams propagating along straight section with external focusing elements. theoretical description this as well self-consistent 3D simulations. Finally, we results experimental observation Plasma-Cascade Instability at frequencies up to 10 THz using SRF linear accelerator built for Coherent electron Cooling experiment *.
Microscopic, or short-wavelength, instabilities are known for drastic reduction of the beam quality and strong amplification noise in a beam. Space charge coherent synchrotron radiation to be leading causes such instabilities. In this paper we present rigorous 3D theory driven by space-charge forces. We define condition when our is applicable an arbitrary accelerator system with coupling. Finally, derive linear integral equation describing instability identify conditions it can reduced...