A5038542612- Laser-Plasma Interactions and Diagnostics
- Gastrointestinal Tumor Research and Treatment
- Laser-Matter Interactions and Applications
- Advanced X-ray Imaging Techniques
- Laser-induced spectroscopy and plasma
- Laser Design and Applications
- Pancreatic and Hepatic Oncology Research
- Gastric Cancer Management and Outcomes
- Nuclear Physics and Applications
- Atomic and Molecular Physics
- Sarcoma Diagnosis and Treatment
- High-pressure geophysics and materials
- Laser Material Processing Techniques
- Particle Accelerators and Free-Electron Lasers
- Ocular and Laser Science Research
- Neuroendocrine Tumor Research Advances
- High-Energy Particle Collisions Research
- Particle physics theoretical and experimental studies
- Quantum Chromodynamics and Particle Interactions
- Advanced Optical Sensing Technologies
- Advanced X-ray and CT Imaging
- Tuberous Sclerosis Complex Research
- Renal cell carcinoma treatment
- Ion-surface interactions and analysis
- Advanced Chemical Physics Studies
Arizona State University
2024
University of Nebraska–Lincoln
2011-2023
University of California, Los Angeles
2022-2023
University of California, San Diego
2019-2023
Cambridge University Hospitals NHS Foundation Trust
2023
Fermi National Accelerator Laboratory
2018
Bhabha Atomic Research Centre
2015
Tata Institute of Fundamental Research
2000-2015
Saha Institute of Nuclear Physics
2015
Thomas Jefferson National Accelerator Facility
2014
We report the generation of MeV x rays using an undulator and accelerator that are both driven by same 100-terawatt laser system. The pulse driving scattering independently optimized to generate a high energy electron beam ($>200\text{ }\text{ }\mathrm{MeV}$) maximize output x-ray brightness. total photon number was measured be $\ensuremath{\sim}1\ifmmode\times\else\texttimes\fi{}{10}^{7}$, source size $5\text{ }\ensuremath{\mu}\mathrm{m}$, divergence angle $\ensuremath{\sim}10\text{...
Gamma-ray photons with energy >9 MeV were produced when second-harmonic-generated laser light (3 eV) inverse-Compton-scattered from a counterpropagating relativistic (∼450 MeV) laser-wakefield-accelerated electron beam. Two pulses the same system used: one to accelerate electrons and scatter. Since two play very different roles in γ-ray generation process, thus have requirements, novel was developed. It separately independently optimized optical properties of pulses. This approach also...
In this paper, we present results on a scalable high-energy electron source based laser wakefield acceleration. The accelerator using 30–80 TW, 30 fs pulses, operates in the blowout regime, and produces high-quality, quasi-monoenergetic beams range 100–800 MeV. These have angular divergence of 1–4 mrad, 5%–25% energy spread, with resulting brightness 1011 electrons mm−2 MeV−1 mrad−2. beam parameters can be tuned by varying plasma conditions. use high-quality pulse appropriate target...
High harmonics generated due to the scattering of relativistic electrons from high intensity laser light is studied. The experiments are carried out with an Nd:Glass system a peak 2×1018 W cm−2 in underdense plasma. It shown that, at intensities, when normalized electric field approaches unity, addition conventional atomic bound there significant contribution harmonic spectrum free electrons. characteristic signatures this found be emission even order harmonics, linear dependence on electron...
Abstract The recent combination of ultra-intense lasers and laser-accelerated electron beams is enabling the development a new generation compact x-ray light sources, coherence which depends directly on beam emittance. Although emittance accelerated can be low, it grow due to effects space charge during free-space propagation. Direct experimental measurement this important property complicated by micron-scale sizes presence intense fields at location where acts. Reported here novel,...
Fourier-transform-limited light pulses were obtained at the laser-plasma interaction point of a 100-TW peak-power laser in vacuum. The spectral-phase distortion induced by dispersion mismatching between stretcher, compressor, and dispersive materials was fully compensated for means an adaptive closed-loop. coherent temporal contrast on sub-picosecond time scale two orders magnitude higher than that without control. This novel phase control capability enabled experimental study dependence...
We investigate the use of energetic electron beams for high-resolution radiography flaws embedded in thick solid objects. A bright, monoenergetic beam (with energy $>100\text{ }\text{ }\mathrm{MeV}$) was generated by process laser-wakefield acceleration through interaction 50-TW, 30-fs laser pulses with a supersonic helium jet. The high energy, low divergence, and small source size these make them ideal radiographic studies cracks or voids dense materials that are placed at large distance...
A repetitive petawatt-class Ti:sapphire laser system operating with high spatial and temporal beam quality is demonstrated. Maximum pulse energy of 30 J obtained via five multi-pass amplification stages. Closed-loop feedback control systems in the domains are used to yield Fourier-transform-limited duration (33.7 fs), diffraction-limited focal spot sizes (with several different tight focusing optics). The parameters have been fully characterized at high-power, monitored real-time, ensure...
The interaction of a laser-produced electron beam with an ultraintense laser pulse in free space is studied. We show that the optical a(0)=0.5 imparts momentum to beam, causing it deflect along propagation direction. observed 3-degree angular deflection found be independent polarization and good agreement theoretical model for electrons tightly focused Gaussian pulse, but only when longitudinal fields are taken into account. This technique used temporally characterize subpicosecond...
Propargyl alcohol (CHCCH2OH) is a known stable isomer of the propenal (CH2CHCHO) molecule that was reported to be present in interstellar medium (ISM). At astrochemical conditions laboratory, icy layers propargyl grown at 85 K were irradiated by 2 keV electrons and probed Fourier Transform InfraRed spectrometer mid-infrared (IR) region, 4000–500 cm−1. ice under studied for first time; therefore, IR spectra amorphous (85 K) crystalline (180 ices can used detect its presence ISM. Moreover, our...
We present recent commissioning results from the ASU Compact x-ray source (CXLS)- an inverse Compton producing sub-picosecond hard x-rays. discuss performance, flux, diagnostics, and designs for a future ICS source.
Results are presented on the generation of high harmonics through scattering relativistic electrons from high-intensity laser light. The characteristic signatures this process found to be emission even-order harmonics, linear dependence electron density, significant amount with circular polarization, and small spatial extent source. emitted as a forward-directed beam divergence 2°–3°. measured profile is in excellent agreement calculations that assume play part process.
We report experimental results on the production and characterization of asymmetric composite supersonic gas flows, created by merging independently controllable flows from multiple nozzles. demonstrate that spatial profiles are adjustable over a large range parameters, including density, density gradient, atomic composition. The were precisely characterized using three-dimensional tomography. creation measurement complex is relevant to numerous applications, ranging laser-produced plasmas...
We demonstrate wavefront correction of terawatt-peak-power laser beams at two distinct and well-separated wavelengths. Simultaneous near diffraction-limited focusability is achieved for both the fundamental (800 nm) second harmonic (400 Ti:sapphire-amplified light. By comparing relative effectiveness various loops, optimal ones are found. different color relies on linear proportionality between their aberrations. This method can enable two-color experiments relativistic intensities.
High-energy X-rays (HEX-rays) with photon energies on order of 100 keV have attractive characteristics, such as comparably low absorption, high spatial resolution and the ability to access inner-shell states heavy atoms. These properties are advantageous for many applications ranging from studies bulk materials investigation in extreme conditions. Ultrafast X-ray diffraction allows direct imaging atomic dynamics simultaneously its natural time length scale. However, using HEX-rays ultrafast...
We demonstrate a novel approach to the generation of femtosecond electron bunch trains via laser-driven wakefield acceleration. use two independent high-intensity laser pulses, drive, and injector, each creating their own plasma wakes. The interaction pulses wakes results in periodic injection free electrons drive wake several mechanisms, including ponderomotive drift, wake-wake interference, pre-acceleration directly by strong fields. Electron were generated with up 4 quasi-monoenergetic...
variety of unusual locations, including the liver, gallbladder, oesophagus,