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We recently demonstrated the production of over a petawatt of peak power in the Nova/Petawatt Laser Facility, generating > 600 J in (approximately) 440 fs. The Petawatt Laser Project was initiated to develop the capability to test...
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We recently demonstrated the production of over a petawatt of peak power in the Nova/Petawatt Laser Facility, generating > 600 J in (approximately) 440 fs. The Petawatt Laser Project was initiated to develop the capability to test the fast ignitor concept for inertial confinement fusion (ICF), and to provide a unique capability in high energy density physics. The laser was designed to produce near kJ pulses with a pulse duration adjustable between 0.5 and 20 ps. At the shortest pulse lengths, this laser is expected to surpass 10 21 W/cm 2 when focused later this year. Currently, this system is limited to 600 J pulses in a 46.3-cm beam. Expansion of the beam to 58 cm, with the installation of 94-cm gratings, will enable 1 kJ operation. Target experiments with petawatt pulses will be possible either integrated with Nova in the 10 beam target chamber or as a stand alone system in an independent, dedicated chamber. Focusing the beam onto a target will be accomplished using an on axis parabolic mirror. The design of a novel targeting system enabling the production of ultrahigh contrast pulses and an easily variable effective focal length is also described.
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This is the final year of the 3-year LDRD-ERD involving Lasers, D&NT, Physics, and ILSA to develope astrophysics experiments on intense lasers such as the Nova and Gekko lasers. During this 3 year period, we have developed a highly successful experiment probing the hydrodynamics of the explosion phase of core-collapse supernovae, which occurs during the first ~3 hours after core collapse. This was in collaboration with the Univ. of Arizona and CEA/Saclay. We also developed a very successful experiment to probe the hydrodynamics of the later time, young remnant phase, meaning the first ~10-20 years after core collapse. This was in collaboration with the Univ. of Michigan and Univ. of Colorado. Finally, we developed during the final year an exquisite experiment to probe the dynamics of radiative, high Mach number astrophysical jets, in collaboration with the Univ. of Maryland and Osaka Univ. Each experiment has received very high visibility, with a multitude of publications, both in the technical journals (most importantly, the astrophysical journals) and in the popular press. The attached publication list shows 25 papers published or submitted to technical journals, 5 articles appearing in the popular press (including a cover story of Sky and Telescope), and 65 conference presentations, ~10 of which were invited talks. The most important papers to come out of this effort was a comprehensive theory paper for Ap. J. establishing the rigorous scaling between laboratory laser experiments and the astrophysical subjects of interest: supernovae, supernova remnants, and jets; and a review article for Science covering this emerging subfield of Astrophysics on Intense Lasers. Since there are so many publications that have resulted from th...
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This is the final year of the 3-year LDRD-ERD involving Lasers, D&NT, Physics, and ILSA to develope astrophysics experiments on intense lasers such as the Nova and Gekko lasers. During this 3 year period, we have developed a highly successful experiment probing the hydrodynamics of the explosion phase of core-collapse supernovae, which occurs during the first ~3 hours after core collapse. This was in collaboration with the Univ. of Arizona and CEA/Saclay. We also developed a very successful experiment to probe the hydrodynamics of the later time, young remnant phase, meaning the first ~10-20 years after core collapse. This was in collaboration with the Univ. of Michigan and Univ. of Colorado. Finally, we developed during the final year an exquisite experiment to probe the dynamics of radiative, high Mach number astrophysical jets, in collaboration with the Univ. of Maryland and Osaka Univ. Each experiment has received very high visibility, with a multitude of publications, both in the technical journals (most importantly, the astrophysical journals) and in the popular press. The attached publication list shows 25 papers published or submitted to technical journals, 5 articles appearing in the popular press (including a cover story of Sky and Telescope), and 65 conference presentations, ~10 of which were invited talks. The most important papers to come out of this effort was a comprehensive theory paper for Ap. J. establishing the rigorous scaling between laboratory laser experiments and the astrophysical subjects of interest: supernovae, supernova remnants, and jets; and a review article for Science covering this emerging subfield of Astrophysics on Intense Lasers. Since there are so many publications that have resulted from this LDRD project, only these two most important papers are attached. The rest are properly referenced, and can be found online or in the library. In anticipation of the closing of the Nova laser, we have successfully proposed transferring the supernova hydrodynamics experiments to the Omega laser at the Univ. of Rochester under the NLUF Program and the radiative jet experiments to the Gekko laser at Osaka University, Japan. The goal of this 3-year endeavor was to technically assess whether intense laser facilities could be used beneficially for astrophysics research. The answer to our progress is best answered by our being asked to supply input to the National Academy of Sciences Decadal Survey for Astronomy and Astrophysics, meaning that this new type of astrophysics research is to be represented in the next 10-yr. plan for astronomy and astrophysics.
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The Fusion Experiments Analysis Facility (FEAF) is a computer facility based on a DEC VAX 11/780 computer. It became operational in late 1982. At that time two manuals were written to aid users and staff in their interactions with...
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The Fusion Experiments Analysis Facility (FEAF) is a computer facility based on a DEC VAX 11/780 computer. It became operational in late 1982. At that time two manuals were written to aid users and staff in their interactions with the facility. Because we've received a number of requests for copies of these manuals from other parts of the lab, we are making them available as UCID's. This guide is intended to provide new users with an introduction to the facility. It contains details about FEAF software, hardware, and operating procedures that are of interest to the general FEAF user. It is meant to supplement (not replace) the operating manuals supplied by software and hardware vendors. (ERA citation 09:021569)
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We recently demonstrated the production of 1.25 PW of peak power in the Nova/Petawatt Laser Facility, generating > 600 J in < 450 fs. Results of the first focused irradiance tests at 500 J and deployment of a novel targeting system are presented.
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Extensive modeling of proposed National Ignition Facility (NIF) ignition targets has resulted in a variety of targets using different materials in the fuel shell, using driving temperatures which range from 250-300 eV, and requiri...
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Extensive modeling of proposed National Ignition Facility (NIF) ignition targets has resulted in a variety of targets using different materials in the fuel shell, using driving temperatures which range from 250-300 eV, and requiring energies from < 1 MJ up to the full 1. 8 MJ design capability of NIF. Recent Nova experiments have shown that hohlraum walls composed of a mixture of high-z materials could result in targets which require about 20% less energy. Nova experiments are being used to quantify benefits of beam smoothing in reducing stimulated scattering processes and laser beam filamentation for proposed gas-filled hohlraum targets on NIF. Use of Smoothing by Spectral Dispersion with 2-3 (Angstrom)of bandwidth results in <4-5% of Stimulated Raman Scattering and less than about 1% Stimulated Brillouin Scattering for intensities less than about 2x10(sup 15)W/cm(sup 2) for this type of hohlraum. The symmetry in Nova gas- filled hohlraums is affected by the gas fill. A large body of evidence now exists which indicates that this effect is due to laser beam filamentation which can be largely controlled by beam smoothing. We present here the firs 3-D simulations of hydrodynamic instability for the NIF point design capsule. These simulations, with the HYDRA radiation hydrodynamics code, indicate that spikes can penetrate up to 10 (mu)m into the 30(mu)m radius hot spot before ignition is quenched. Using capsules whose surface is modified by laser ablation, Nova experiments have been used to quantify the degradation of implosions subject to near NIF levels of hydrodynamic instability.
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Nova and Novette are large complex experimental laser facilities which require extensive and sophisticated control systems for their successful operation. Often, in major controls projects, certain invisible aspects of the project...
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Nova and Novette are large complex experimental laser facilities which require extensive and sophisticated control systems for their successful operation. Often, in major controls projects, certain invisible aspects of the project, such as overall strategy, management, resources and historical constraints, have a more profound effect upon success than any specific hardware/software design. The design and performance of the Nova/Novette laser control system will be presented with special emphasis upon these often controversial aspects. (ERA citation 09:036989)
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This is the final report for the LDRD 90-ERI-009 involving Lasers, and MRI to develop dynamic diffraction experiments to diagnose shocked solid-state lattices on intense lasers such at the Nova and Trident lasers. This was in coll...
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This is the final report for the LDRD 90-ERI-009 involving Lasers, and MRI to develop dynamic diffraction experiments to diagnose shocked solid-state lattices on intense lasers such at the Nova and Trident lasers. This was in collaboration with the US San Diego, University of Oxford, and LANL. During this period, we have developed successful dynamic diffraction experiments on (111) and (400) Silicon lattices, both on the Nova laser and on the Trident laser. We also developed simultaneous transmission Bragg diffraction measurements off orthogonal lattice planes, to look for evidence of the transition to 3D. No evidence for lateral lattice adjustment was observed for (400 Si), which is a theoretical puzzle still under active investigation.
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The evolution of the Rayleigh-Taylor (RT) instability at an embedded, or classical, interface is examined in a series of experiments at the Nova laserfacility .(reference for Nova) These experiments focused on the transition from ...
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The evolution of the Rayleigh-Taylor (RT) instability at an embedded, or classical, interface is examined in a series of experiments at the Nova laserfacility .(reference for Nova) These experiments focused on the transition from the linear to nonlinear regimes for both single- and multimode initialperturbations. The development of a single mode at the embedded interface is compared to its evolution at an ablation front and the effect of ablativestabilization is experimentally demonstrated. The multimode experiments have shown evidence of the process of bubble competition, whereinneighboring structures either continue to rise or are washed downstream in the flow depending upon their relative size. The experiments with simulations performed with either the LASNEX are comparedcode (G. B.Zimmerman and W. L. Kruer, Comments Plasma Phys. Controlled Fusion 2,51 (1975).), a two-dimensional Lagrangian radiation-hydrodynamics code, or CALE (R. Tipton, reference for CALE) , a two-dimensional arbitrary Lagrange-Eulerian radiation-hydrodynamics code.
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