A5003778542- Laser-Plasma Interactions and Diagnostics
- Laser-induced spectroscopy and plasma
- Laser-Matter Interactions and Applications
- High-pressure geophysics and materials
- Magnetic Properties and Applications
- Laser Design and Applications
- Laser Material Processing Techniques
- Magnetic Properties of Alloys
- Nuclear Physics and Applications
- Atomic and Molecular Physics
- Terahertz technology and applications
- Spectroscopy and Laser Applications
- Advanced X-ray Imaging Techniques
- Solid State Laser Technologies
- Microstructure and Mechanical Properties of Steels
- Ion-surface interactions and analysis
- Electromagnetic Effects on Materials
- Quantum, superfluid, helium dynamics
- Magnetic Properties and Synthesis of Ferrites
- Iron oxide chemistry and applications
- Optical Systems and Laser Technology
- Gas Dynamics and Kinetic Theory
- Radiation Effects and Dosimetry
- Structural Health Monitoring Techniques
- Electrodeposition and Electroless Coatings
Rutherford Appleton Laboratory
2014-2024
Lawrence Livermore National Laboratory
2020-2023
Massachusetts Institute of Technology
2021-2023
The University of Texas at Austin
2023
University of California, Los Angeles
2023
Florida Agricultural and Mechanical University
2023
General Atomics (United States)
2023
Colorado State University
2023
Science and Technology Facilities Council
2019-2021
Georgia Institute of Technology
2021
ZnSe axicon is used to efficiently generate approximations diffraction-free Bessel function beams at λ = 10.6 μm. The central spot radius of ~ 170 μm generated when the illuminated by a plane wave maintained for distances up 11 cm with sufficient laser power allow drilling plexiglass be demonstrated.
Significance Terahertz (THz) radiation, with frequencies spanning from 0.1 to 10 THz, has long been the most underdeveloped frequency band in electromagnetic waves, mainly due dearth of available high-power THz sources. Although last decades have seen a surge electronic and optical techniques for generating intense all sources reported until now failed produce above-millijoule (mJ) pulses. We present source that enables pulse energy up tens mJ, by using an laser irradiate metal foil.
The electronic amplifier, described herein, is designed to measure extremely small d.c. and low frequency a.c. voltages in impedance sources. Expressing the electrical noise terms of equivalent input voltage with a 5-ohm resistance 5-milliamp. Esterline-Angus recorder, maximum departure from mean does not exceed 1.5×10−9 volt. Under laboratory conditions drift less than 5×10−9 volt over period 8 hours. amplifier compact rugged, it affected by vibrations or accelerations experienced moving...
When a circular cylinder is immersed in some gases at pressures near 0.05 Torr, application of weak magnetic field (0.2-200 Oe) parallel to the axis results torque about that when temperature difference exists between gas and surface. This linear function difference. It reverses either gradient or direction reversed. At given pressure exhibits maximum definite value field, position this characteristic involved.
Abstract Control of the collective response plasma particles to intense laser light is intrinsic relativistic optics, development compact laser-driven particle and radiation sources, as well investigations some laboratory astrophysics phenomena. We recently demonstrated that a aperture produced in an ultra-thin foil at focus can induce diffraction, enabling polarization-based control motion electrons. Here we show under these conditions electron dynamics are mapped into beam protons...
Giant electromagnetic pulses (EMP) generated during the interaction of high-power lasers with solid targets can seriously degrade electrical measurements and equipment. EMP emission is caused by acceleration hot electrons inside target, which produce radiation across a wide band from DC to terahertz frequencies. Improved understanding control vital as we enter new era high repetition rate, intensity (e.g. Extreme Light Infrastructure). We present recent data VULCAN laser facility that...
New short-pulse kilojoule, Petawatt-class lasers, which have recently come online and are coupled to large-scale, many-beam long-pulse facilities, undoubtedly serve as very exciting tools capture transformational science opportunities in high energy density physics. These lasers also happen reside a unique laser regime: high-energy (kilojoule), relatively long (multi-picosecond) pulse-lengths, large (10s of micron) focal spots, where their use driving energetic particle beams is largely...
An ever-increasing number of strong-field applications, such as ultrafast coherent control over matter and light, require driver light pulses that are both high power spectrally tunable. The realization a source in the terahertz (THz) band has long been formidable challenge. Here, we demonstrate, via experiment theory, efficient production terawatt (TW)-level THz from high-intensity picosecond laser irradiation on metal foil. It is shown spectrum can be manipulated effectively by tuning...
Ferromagnetic domain patterns on single-crystal whiskers of pure iron have been studied by using the Bitter powder technique. Patterns observed both magnetized and unmagnetized specimens in cases straightforward interpretations can be given. Whiskers with axes along [111] [100] directions observations indicate that crystals perfect geometry a very simple structure state.
In this experiment the gyromagnetic ratio of a sample very pure iron was determined. The wound with magnetizing coil and supported as torsional pendulum in an evacuated space almost completely free residual magnetic fields. Changes amplitude were brought about by repeated synchronized reversals current. These changes measured along corresponding moment sample. average value obtained for 1.0278\ifmmode\pm\else\textpm\fi{}0.0014 times mass-to-charge electron.
We report on the selective acceleration of carbon ions during interaction ultrashort, circularly polarized and contrast-enhanced laser pulses, at a peak intensity 5.5×10^{20} W/cm^{2}, with ultrathin foils. Under optimized conditions, energies per nucleon bulk reached significantly higher values than contaminant protons (33 MeV/nucleon vs 18 MeV), unlike what is typically observed in laser-foil experiments. Experimental data, supporting simulations, emphasize different dominant mechanisms...
A scaling study of short-pulse laser-driven proton and electron acceleration was conducted as a function pulse duration, laser energy, intensity in the multi-picosecond (ps) regime (∼0.8 ps–20 ps). Maximum energies significantly greater than established laws were observed, consistent with observations at other multi-ps facilities. In addition, maximum temperatures this found to be strongly dependent on duration preplasma conditions. modified model is presented that able better represent...
Magnetomechanical ratios for four Fe-Co alloys were measured by the Einstein-de Haas method. Previous measurements of Fe, Co, Ni, and Fe-Ni Co-Ni are reviewed, thus completing magnetomechanical determinations binary these three ferromagnetic elements. all different from those calculated effective atomic magnetic moments angular momenta in experiments on unalloyed constituents.
We measure a record 96 ±2.5% specularly reflected energy fraction from an interaction with plasma mirror (PM) surface preionized by controlled prepulse and find that the optical quality is dependent on inter pulse time delay. Simulations show main strong function of density scale length, which increases delay reaches peak reflectivity for length 0.3 μm, achieved here separation 3 ps. It found incident laser quasi near field intensity distribution leads to nonuniformities in this expansion...
Magnetic domain patterns have been observed on iron whiskers growing in [111], [100], and [110] directions. In most cases the unmagnetized are very simple subject to straight forward interpretation. Patterns {100} faces change after annealing above Curie temperature. Domain arrangements which produce intersecting boundaries at crystal surface do not collect magnetite. Dagger form {110} surfaces under application of normal fields studied effect misoriented these has investigated.
Spectrally-peaked proton beams of high charge (, , nC ) have been observed from the interaction an intense laser ( W cm−2) with ultrathin CH foils, as measured by spectrally-resolved full beam profiles. These are reproducibly generated for foil thicknesses 5–100 nm, and exhibit narrowing divergence decreasing target thickness down to 5 nm. Simulations demonstrate that narrow energy spread feature is a result buffered acceleration protons. The radiation pressure at front results in asymmetric...
After a population of laser-driven hot electrons traverses limited thickness solid target, these will encounter the rear surface, creating TV/m fields that heavily influence subsequent hot-electron propagation. Electrons fail to overcome electrostatic potential reflux back into target. Those do field escape Here, using particle-in-cell (PIC) code EPOCH and particle tracking large macro-particles, we investigate refluxing escaping electron populations, as well magnitude, spatial temporal...
Fast electron transport in Si, driven by ultraintense laser pulses, is investigated experimentally and via 3D hybrid particle-in-cell simulations. A transition from a Gaussian-like to an annular fast beam profile demonstrated explained resistively generated magnetic fields. The results highlight the potential completely transform pattern tailoring resistivity-temperature at temperatures as low few eV.
High-intensity laser–solid interactions generate relativistic electrons, as well high-energy (multi-MeV) ions and x-rays. The directionality, spectra total number of electrons that escape a target-foil is dependent on the absorption, transport rear-side sheath conditions. Measuring escaping target will aid in improving our understanding these absorption processes rear-surface fields retard accelerate via normal acceleration (TNSA) mechanism. A comprehensive Geant4 study was performed to help...
Abstract We describe the first demonstration of plasma mirrors made using freely suspended, ultra-thin films formed dynamically and in - situ . also present novel particle-in-cell simulations that for time incorporate multiphoton ionization dielectric models are necessary describing mirrors. Dielectric a crucial component high intensity laser applications such as ion acceleration solid target harmonic generation because they greatly improve pulse contrast. use liquid crystal 8CB introduce an...
The PROBIES diagnostic is a new, highly flexible, imaging and energy spectrometer designed for laser-accelerated protons. can detect low-mode spatial variations in the proton beam profile while resolving multiple energies on single detector or more. When radiochromic film stack employed "single-shot mode," resolution of be greatly increased reducing need large numbers films; example, recently deployed version allowed 180 unique measurements spanning ∼3 to 75 MeV with <0.4 using just 20 films...
Views Icon Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Twitter Facebook Reddit LinkedIn Tools Reprints and Permissions Cite Search Site Citation G. Scott, R. V. Coleman; Domain Changes during Longitudinal Magnetization of Iron Whiskers. Journal Applied Physics 1 December 1957; 28 (12): 1512–1513. https://doi.org/10.1063/1.1722690 Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar...