A5057933172- Laser-Plasma Interactions and Diagnostics
- Laser-induced spectroscopy and plasma
- Combustion and Detonation Processes
- Laser-Matter Interactions and Applications
- High-pressure geophysics and materials
- Energetic Materials and Combustion
- Laser Design and Applications
- Magnetic confinement fusion research
- Nuclear Physics and Applications
- Cold Fusion and Nuclear Reactions
- Atomic and Molecular Physics
- Electromagnetic Launch and Propulsion Technology
- Nuclear Issues and Defense
- Nuclear reactor physics and engineering
- Fusion and Plasma Physics Studies
- Fusion materials and technologies
- Astro and Planetary Science
- Mass Spectrometry Techniques and Applications
- Rocket and propulsion systems research
- High-Velocity Impact and Material Behavior
- Plasma Diagnostics and Applications
- Engineering and Material Science Research
- Ion-surface interactions and analysis
- Particle Dynamics in Fluid Flows
- Combustion and flame dynamics
University of Rochester
2015-2025
Energetics (United States)
2014-2025
Applied Energetics (United States)
2012-2025
Lawrence Livermore National Laboratory
2008-2022
Los Alamos National Laboratory
2022
Massachusetts Institute of Technology
2008
Fermi National Accelerator Laboratory
2002
University of Nebraska–Lincoln
1986
A novel method by C. Zhou and R. Betti [Bull. Am. Phys. Soc. 50, 140 (2005)] to assemble ignite thermonuclear fuel is presented. Massive cryogenic shells are first imploded direct laser light with a low implosion velocity on adiabat leading assemblies large areal densities. The assembled ignited from central hot spot heated the collision of spherically convergent ignitor shock return shock. resulting assembly features hot-spot pressure greater than surrounding dense pressure. Such...
The physics of thermonuclear ignition in inertial confinement fusion (ICF) is presented the familiar frame a Lawson-type criterion. product plasma pressure and time Pτ for ICF cast terms measurable parameters its value estimated cryogenic implosions. An overall parameter χ including pressure, time, temperature derived to complement Pτ. A metric performance assessment should include both are compared between magnetic-confinement fusion. It found that implosions on OMEGA [T. R. Boehly et al.,...
A model for the deceleration phase and marginal ignition of imploding capsules is derived by solving a set ordinary differential equations describing hot-spot energy balance shell dynamics including return shock propagation. It found that heat flux leaving hot spot goes back in form internal PdV work material ablated off inner-shell surface. Though temperature reduced conduction losses, density increases due to such way pressure approximately independent conduction. For temperatures...
Fast ignition is a two-step inertial confinement fusion concept where megaelectron volt electrons ignite the compressed core of an imploded fuel capsule driven by relatively low-implosion velocity. Initial surrogate cone-in-shell, fast-ignitor experiments using highly shaped driver pulse to assemble dense in front cone tip were performed on OMEGA/OMEGA EP Laser [T. R. Boehly et al., Opt. Commun. 133, 495 (1997); L. J. Waxer Photonics News 16, 30 (2005)]. With optimal timing, OMEGA produced...
The theory of ignition for inertial confinement fusion capsules [R. Betti et al., Phys. Plasmas 17, 058102 (2010)] is used to assess the performance requirements cryogenic implosion experiments on Omega Laser Facility. hydrodynamic similarity developed in both one and two dimensions tested using multimode simulations with hydrocode DRACO [P. B. Radha 12, 032702 (2005)] hydro-equivalent implosions (implosions same velocity, adiabat, laser intensity). scale direct-drive OMEGA National Ignition...
Spherical shock-ignition experiments on OMEGA used a novel beam configuration that separates low-intensity compression beams and high-intensity spike beams. Significant improvements in the performance of plastic-shell, D2 implosions were observed with repointed The analysis coupling energy into imploding capsule indicates absorbed hot-electron contributes to coupling. backscattering laser was measured reach up 36% at single-beam intensities ∼8 × 1015 W/cm2. Hard x-ray measurements revealed...
Polar drive [Skupsky et al., Phys. Plasmas 11, 2763 (2004)] will enable direct-drive experiments to be conducted on the National Ignition Facility (NIF) [Miller Opt. Eng. 43, 2841 (2004)], while facility is configured for x-ray drive. A polar-drive ignition design NIF has been developed that achieves a gain of 32 in two-dimensional (2-D) simulations, which include single- and multiple-beam nonuniformities ice outer-surface roughness. This requires both single-beam UV polarization smoothing...
Shock ignition is a two-step inertial confinement fusion concept where strong shock wave launched at the end of laser pulse to ignite compressed core low-velocity implosion. Initial shock-ignition technique experiments were performed OMEGA Laser Facility [T. R. Boehly et al., Opt. Commun. 133, 495 (1997)] using 40-μm-thick, 0.9-mm-diam, warm surrogate plastic shells filled with deuterium gas. The showed significant improvement in performance low-adiabat, implosions compared conventional...
A multidimensional measurable criterion for central ignition of inertial-confinement-fusion capsules is derived. The accounts the effects implosion nonuniformities and depends on three parameters: neutron-averaged total areal density (rhoR(n)(tot)), ion temperature (T(n)), yield over clean (YOC=ratio measured neutron to predicted one-dimensional yield). YOC measures uniformity. can be approximated by chi=(rhoR(n)(tot))(0.8) x (T(n)/4.7)(1.7)YOC(mu)>1 (where rhoR in g cm(-2), T keV, mu...
Recent experiments on the Laboratory for Laser Energetics' OMEGA laser have been carried out to produce strong shocks in solid spherical targets with direct illumination. The are launched at pressures of several hundred Mbars and reach Gbar upon convergence. results relevant validation shock-ignition scheme development an experimental platform study material properties pressures. investigate strength ablation pressure hot-electron production incident intensities ∼2 6 × 1015 W/cm2 demonstrate...
Nonuniformities present in the laser illumination and target laser-driven inertial confinement fusion experiments lead to an asymmetric compression of target, resulting inefficient conversion shell kinetic energy thermal hot-spot plasma. In this paper, effects cryogenic deuterium tritium laser-direct-drive implosions are examined using a suite nuclear x-ray diagnostics on OMEGA laser. The neutron-averaged velocity (u→hs) apparent ion temperature (Ti) asymmetry determined from neutron...
Statistical modeling of experimental and simulation databases has enabled the development an accurate predictive capability for deuterium-tritium layered cryogenic implosions at OMEGA laser [V. Gopalaswamy et al.,Nature 565, 581 (2019)]. In this letter, a physics-based statistical mapping framework is described used to uncover dependencies fusion yield. This model identify quantify degradation mechanisms yield in direct-drive on OMEGA. The found be reduced by ratio beam target radius,...
Improving the performance of inertial confinement fusion implosions requires physics models that can accurately predict response to changes in experimental inputs. Good predictive capability has been demonstrated for yield using a statistical mapping simulated outcomes data [Gopalaswamy et al., Nature 565(771), 581–586 (2019)]. In this paper, physics-based approach is used extract and quantify all major sources degradation direct-drive on OMEGA laser. The found be dependent age deuterium...
The theory of laser-induced adiabat shaping is carried out for inertial confinement fusion (ICF) capsules. It shown that a significant improvement the stability characteristics ICF implosions can be achieved by inside imploding shell. optimized profile has maximum on outer ablation surface to lower Rayleigh–Taylor growth rates, and minimum shell inner high compressibility neutron yields. Laser-induced produced via relaxation using weak prepulse followed laser shut-off main pulse.
Shock ignition [R. Betti et al., Phys. Rev. Lett. 98, 155001 (2007)] is being pursued as a viable option to achieve on the National Ignition Facility (NIF). Shock-ignition target designs use high-intensity laser spike at end of low-adiabat assembly pulse launch spherically convergent strong shock ignite hot spot an imploding capsule. A shock-ignition design for NIF presented. One-dimensional simulations indicate threshold factor 4.1 with gain 58. polar-drive beam-pointing configuration...
We report on laser-driven, strong-shock generation and hot-electron production in planar targets the presence of a pre-plasma at shock-ignition (SI) relevant laser conditions. 2-D simulations reproduce shock dynamics well, indicating ablator shocks up to 75 Mbar have been generated. observe temperatures ∼70 keV intensities 1.4 × 1015 W/cm2 with multiple overlapping beams driving two-plasmon decay instability. When extrapolated SI-relevant ∼1016 W/cm2, hot electron temperature will likely...
The study of Rayleigh–Taylor instability in the deceleration phase inertial confinement fusion implosions is carried out using three-dimensional (3-D) radiation-hydrodynamic Eulerian parallel code DEC3D. We show that yield-over-clean a strong function residual kinetic energy (RKE) for low modes. Our analytical models indicate behavior larger hot-spot volumes observed modes and consequential pressure degradation can be explained terms increasing RKE. These results are derived simple adiabatic...
Hohlraums are hollow cylindrical cavities with high-Z material walls used to convert laser energy into uniform x-ray radiation drives for inertial confinement fusion capsule implosions and high density physics experiments. Credible computational modeling of hohlraums requires detailed coupling physics, hydrodynamics, transport, heat atomic physics. We report on improvements Los Alamos National Laboratory's xRAGE radiation-hydrodynamics code in order enable hohlraum modeling. xRAGE's Eulerian...