A5042869765- Laser-Plasma Interactions and Diagnostics
- Laser-Matter Interactions and Applications
- Laser-induced spectroscopy and plasma
- Advanced X-ray Imaging Techniques
- High-pressure geophysics and materials
- Laser Design and Applications
- Advanced Fiber Laser Technologies
- Nuclear Physics and Applications
- Atomic and Molecular Physics
- Solid State Laser Technologies
- Magnetic confinement fusion research
- Optical Systems and Laser Technology
- Particle Accelerators and Free-Electron Lasers
- Infrared Target Detection Methodologies
- Adaptive optics and wavefront sensing
- Advanced optical system design
- Photorefractive and Nonlinear Optics
- Optical measurement and interference techniques
- Laser Material Processing Techniques
- Advanced Fiber Optic Sensors
- Radiation Detection and Scintillator Technologies
- Combustion and Detonation Processes
- Diamond and Carbon-based Materials Research
- Traumatic Ocular and Foreign Body Injuries
- Advanced Surface Polishing Techniques
University of Rochester
2008-2024
Energetics (United States)
2006-2024
Kodak (United States)
1989-1999
Eastman Chemical Company (United States)
1990
Carestream (United States)
1989
AbstractThe laser challenges and state of the art in high-energy, solid-state petawatt lasers for fast ignition (FI) research are reviewed. A number new systems currently under construction or being planned that will facilitate proof-of-principle FI experiments. Recent technological advances each major ultrafast subsystems reported, including chirped-pulse generation broadband amplification front end, high-energy amplification, pulse compression with adaptive wavefront correction. Unique...
OMEGA EP (extended performance) is a petawatt-class addition to the existing 30-kJ, 60-beam Laser Facility at University of Rochester. It will enable high-energy picosecond backlighting high-energy-density experiments and inertial confinement fusion implosions, investigation advanced-ignition such as fast ignition, exploration phenomena. The short-pulse beams have flexibility be directed either target chamber, or new, auxiliary chamber for independent experiments. This paper detail progress...
Time-resolved K(α) spectroscopy has been used to infer the hot-electron equilibration dynamics in high-intensity laser interactions with picosecond pulses and thin-foil solid targets. The measured K(α)-emission pulse width increases from ~3 6 ps for intensities ~10(18) 10(19) W/cm(2). Collisional energy-transfer model calculations suggest that hot electrons mean energies ~0.8 2 MeV are contained inside target. inferred broadly consistent ponderomotive scaling over relevant intensity range.
The impact of high-frequency spectral phase modulation on the temporal contrast ultrafast pulses is evaluated. Expressions are derived for low-intensity pedestal produced by optical component surface roughness within pulse stretchers and compressors. Phase noise, added across near-field a spectrally dispersed beam, produces space–time coupling in far-field or focal plane. swept an area plane many times size diffraction-limited spot. Simulations performed generic compressors that show...
The effect of medium-Z doping plastic ablators on laser imprinting and Rayleigh–Taylor (RT) instability growth was studied using spherical direct-drive implosions the OMEGA Laser System [T. R. Boehly et al., Opt. Commun. 133, 495 (1977)]. targets were (CH) shells, with an outer diameter 860 μm a thickness 22 μm, volume doped varied concentration Si (4.3% 7.4%) Ge (3.9%). imploded 48 beams low-adiabat, triple-picket shape pulse peak intensity 4×1014W/cm2, duration 2.5 ns. shells x-ray...
A technique to measure the shell trajectory in direct-drive inertial confinement fusion implosions is presented. The x-ray self emission of target measured with an framing camera. Optimized filtering limits from corona plasma, isolating a sharp intensity gradient very near ablation surface. This enables one radius imploding accuracy better than 1 μm and determine 200-ps average velocity 2%.
A high-performance cryogenic DT inertial confinement fusion implosion experiment is an especially challenging backlighting configuration because of the high self-emission core at stagnation and low opacity shell. High-energy petawatt lasers such as OMEGA EP promise significantly improved capabilities by generating x-ray intensities short emission times. narrowband imager with astigmatism-corrected bent quartz crystal for Si Heα line ∼1.86 keV was developed to record backlit images...
Self-emission x-ray shadowgraphy provides a method to measure the ablation-front trajectory and low-mode nonuniformity of target imploded by directly illuminating fusion capsule with laser beams. The technique uses time-resolved images soft x-rays ( ${>}1$ keV) emitted from coronal plasma imaged onto an framing camera determine position ablation front. Methods used accurately radius ${\it\delta}R=\pm 1.15~{\rm\mu}\text{m}$ ), image-to-image timing ${\it\delta}({\rm\Delta}t)=\pm 2.5$ ps)...
We describe a phase-conjugate interferometer that consists of partially transmitting conventional mirror placed in front and close proximity to mirror. The is self-referencing, compact, insensitive environmental disturbances, provides twice the sensitivity (nonphase-conjugate) interferometers, produces direct representation an incident wave front. have constructed such device using internally self-pumped phase conjugation barium titanate used characterize produced by aberrated optical system.
A 10-ps, 263-nm (4ω) laser is being built to probe plasmas produced on the OMEGA EP [J. H. Kelly, L. J. Waxer, V. Bagnoud, I. A. Begishev, Bromage, B. E. Kruschwitz, T. Kessler, S. Loucks, D. N. Maywar, R. McCrory et al., Phys. IV France 133, 75–80 (2006)]10.1051/jp4:2006133015. suite of optical diagnostics (schlieren, interferometry, and grid image refractometry) has been designed diagnose characterize a wide variety plasmas. Light scattered by beam collected an f/4 catadioptric telescope...
Using a spherically bent quartz crystal for the Si Heα line at ∼1.865 keV, narrowband x-ray imager has been deployed Omega Laser Facility to record backlit images of direct-drive laser implosions. The was cut along $10\bar 11$101¯1 planes 2d spacing 0.687 nm, resulting in Bragg angle 83.9°. Apertures front were used control astigmatism imaging system. show high signal-to-background ratio >10:1 with backlighter energies ≥1.5 kJ 10-ps pulse duration and spatial resolution better than 20 μm.
The Scattered Light Time-history Diagnostic (SLTD) is being implemented at the National Ignition Facility (NIF) to greatly expand angular coverage of absolute scattered-light measurements for direct- and indirect-drive inertial confinement fusion (ICF) experiments. SLTD array will ultimately consist 15 units mounted a variety polar azimuthal angles on NIF target chamber, complementing existing backscatter suite. Each unit collects diffuses scattered light onto set three optical fibers, which...
X-ray imaging using shaped crystals in Bragg reflection is a powerful technique used high-energy-density physics experiments. The characterization of these crystal assemblies with conventional x-ray sources very difficult because the required angular resolution order ∼10 μrad and narrow bandwidth crystal. 10-J, 1-ps Multi-Terawatt (MTW) laser at Laboratory for Laser Energetics was to characterize set assemblies. small spot size (of 5 μm) high power (>1018 W/cm2) this make it possible...
A high-resolving-power x-ray spectrometer has been developed for the OMEGA EP Laser System based on a spherically bent Si [220] crystal with radius of curvature 330 mm and Spectral Instruments (SI) 800 Series charge-coupled device. The instrument measures time-integrated emission spectra in 7.97- to 8.11-keV range, centered Cu Kα1 line. To demonstrate performance under high-power conditions, Kα1,2 were measured from foils irradiated by laser 100-J, 1-ps pulses at focused intensities above...
A front end is being constructed for ultra-intense optical parametric chirped-pulse amplification (OPCPA) system at 910 nm. Technologies are developed large-scale systems based on deuterated potassium dihydrogen phosphate (DKDP) amplifiers that could be pumped by kilojoule-class Nd:glass lasers such as OMEGA EP. Results reviewed a prototype white-light-seeded chain of noncollinear (NOPA's) and the development cylindrical Öffner stretcher has advantages over standard stretchers ultra-intense,...
An Öffner stretcher using cylindrical mirrors is evaluated for ultra-broadband, high-contrast lasers. Adding a grating reduces chromatic aberration, and replacing the spherical eliminates intermediate foci, increasing energy throughput improving temporal contrast.
A new streaked soft x-ray imager has been designed for use on high energy-density (HED) physics experiments at the National Ignition Facility based Lawrence Livermore Laboratory. This uses a slit aperture, single shallow angle reflection from nickel mirror, and filtering to, when coupled to one of NIF’s streak cameras, record 4× magnification, one-dimensional image an source with spatial resolution less than 90 μm. The energy band pass produced depends upon filter material used; first...
The Hobby-Eberly Telescope uses a 11-meter diameter F/1.45 segmented spherical primary mirror. A mirror of this size generates large amounts aberration. To be used successfully in tilted optical Arecibo type telescope, the aberration needs to corrected. This means that tracking astronomical targets is achieved through moving tracker package which imposes somewhat severe packaging constraints. Given these constraints, novel methods must employed correct aberrations with Spherical Aberration...
Ultra-intense optical parametric chirped-pulse amplification (OPCPA) requires a high-performance front-end at 910 nm. Progress is reviewed on developing white-light–seeded chain of noncollinear amplifiers (NOPA's) and cylindrical Öffner stretcher.
OMEGA EP (Extended Performance) is a petawatt-class addition to the existing 30-kJ, 60-beam Laser Facility at University of Rochester. Activation complete and results will be described.
The measurement of the spectral distibution radiation from individual points on earth's surface provides important information material composition those points. To collect data over large areas, it is necessary to use either airborne or spaceborne platforms. In this paper, different approaches collecting such a lightweight platform will be reviewed. tuning technologies as acousto-optical filters, liquid crystal and linearly variable well slit spectrometer systems, rebiewed. Features...
In this paper, we report on a crystal based x-ray imaging system fielded at the OMEGA EP laser facility. This new has pointing accuracy of +/100 μm, temporal resolution down to 100 ps (depending backlighter characteristics), variable magnification, and spatial 21.9 µm object plane magnification 15×. The is designed use along that satisfies Bragg condition for x ray interest. thin then bent into spherical geometry attached glass backing substrate hold it in diagnostic, rays are imaged onto...
A dual-channel streaked soft x-ray imager has been designed and used on high energy-density physics experiments at the National Ignition Facility. This creates two images of same source using slit apertures a single shallow angle reflection from nickel mirror. Thin filters are to create narrow band pass 510 eV 360 eV. When measuring Planckian spectrum, brightness ratio can be translated into color-temperature, provided that spectral sensitivity is well known. To reduce uncertainty remove...