S. H. Batha
A5042402770- Laser-Plasma Interactions and Diagnostics
- Laser-induced spectroscopy and plasma
- Magnetic confinement fusion research
- Nuclear Physics and Applications
- Laser-Matter Interactions and Applications
- Ionosphere and magnetosphere dynamics
- Fusion materials and technologies
- High-pressure geophysics and materials
- Atomic and Molecular Physics
- Particle accelerators and beam dynamics
- Radiation Detection and Scintillator Technologies
- Combustion and Detonation Processes
- Energetic Materials and Combustion
- Laser Design and Applications
- Cold Fusion and Nuclear Reactions
- Nuclear reactor physics and engineering
- Atomic and Subatomic Physics Research
- Ion-surface interactions and analysis
- Solar and Space Plasma Dynamics
- Advanced X-ray and CT Imaging
- Superconducting Materials and Applications
- Plasma Diagnostics and Applications
- Radioactive contamination and transfer
- Advanced X-ray Imaging Techniques
- Crystallization and Solubility Studies
Los Alamos National Laboratory
2016-2025
Lawrence Livermore National Laboratory
1992-2020
Virginia Tech
2020
Ben-Gurion University of the Negev
2020
The University of Texas at San Antonio
2016-2019
General Atomics (United States)
2014-2019
Fusion Academy
1993-2014
Fusion (United States)
1993-2014
Massachusetts Institute of Technology
1994-2014
CEA DAM Île-de-France
2014
A new tokamak confinement regime has been observed on the Tokamak Fusion Test Reactor (TFTR) where particle and ion thermal diffusivities drop precipitously by a factor of \ensuremath{\sim}40 to neoclassical level for particles much less than value ions in region with reversed shear. This enhanced shear mode allows central electron density rise from 0.45 \ifmmode\times\else\texttimes\fi{} ${10}^{20}$ ${\mathrm{m}}^{\ensuremath{-}3}$ \ensuremath{\sim}1.2 ${T}_{i}\ensuremath{\sim}24$ keV...
For more than half a century, researchers around the world have been engaged in attempts to achieve fusion ignition as proof of principle various concepts. Following Lawson criterion, an ignited plasma is one where heating power high enough overcome all physical processes that cool plasma, creating positive thermodynamic feedback loop with rapidly increasing temperature. In inertially confined fusion, state can begin "burn propagation" into surrounding cold fuel, enabling possibility energy...
The National Ignition Facility (NIF) at Lawrence Livermore Laboratory includes a precision laser system now capable of delivering 1.8 MJ 500 TW 0.35-μm light to target. NIF has been operational since March 2009. A variety experiments have completed in support NIF's mission areas: national security, fundamental science, and inertial fusion energy. capabilities infrastructure are place its missions with nearly 60 X-ray, optical, nuclear diagnostic systems. primary goal the Campaign (NIC) on...
On December 5, 2022, an indirect drive fusion implosion on the National Ignition Facility (NIF) achieved a target gain <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:mrow><a:msub><a:mrow><a:mi>G</a:mi></a:mrow><a:mrow><a:mtext>target</a:mtext></a:mrow></a:msub></a:mrow></a:math> of 1.5. This is first laboratory demonstration exceeding “scientific breakeven” (or <c:math xmlns:c="http://www.w3.org/1998/Math/MathML"...
Turbulent fluctuations in plasmas with reversed magnetic shear have been investigated on the Tokamak Fusion Test Reactor. Under intense auxiliary heating, these are observed to bifurcate into two states different transport properties. In state better confinement, it has found that level of is very small throughout most region negative shear. By contrast, lower confinement characterized by large bursts which suggest a competition between driving and suppression turbulence. These results...
Ignition requires precisely controlled, high convergence implosions to assemble a dense shell of deuterium-tritium (DT) fuel with ρR&gt;∼1 g/cm2 surrounding 10 keV hot spot ρR ∼ 0.3 g/cm2. A working definition ignition has been yield ∼1 MJ. At this the α-particle energy deposited in would have ∼200 kJ, which is already ∼10 × more than kinetic typical implosion. The National Campaign includes low dudded layers study and optimize hydrodynamic assembly diagnostics rich environment. mixture...
We present a data-based model for low mode asymmetry in gas-fill hohlraum experiments on the National Ignition Facility {NIF [Moses et al., Fusion Sci. Technol. 69, 1 (2016)]} laser. This is based hypothesis that these fill hohlraums dominated by hydrodynamics of expanding, density, high-Z (gold or uranium) “bubble,” which occurs where intense outer cone laser beams hit wall. developed simple states implosion symmetry becomes more oblate as bubble size large compared to radius capsule...
Wall conditioning in the Tokamak Fusion Test Reactor (TFTR) [K. M. McGuire et al., Phys. Plasmas 2, 2176 (1995)] by injection of lithium pellets into plasma has resulted large improvements deuterium–tritium fusion power production (up to 10.7 MW), Lawson triple product 1021 m−3 s keV), and energy confinement time 330 ms). The maximum current for access high-performance supershots been increased from 1.9 2.7 MA, leading stable operation at stored values greater than 5 MJ. amount on limiter...
Off-axis sawteeth are often observed in reversed magnetic shear plasmas when the minimum safety factor $q$ is near or below 2. Fluctuations with $m/n\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}2/1$ ( $m$ and $n$ poloidal toroidal mode numbers) appear before after crashes. Detailed comparison has been made between measured ${T}_{e}$ profile evaluation during crash a nonlinear numerical magnetohydrodynamics simulation. The good agreement observation simulation indicates that off-axis...
Peak fusion power production of 6.2\ifmmode\pm\else\textpm\fi{}0.4 MW has been achieved in TFTR plasmas heated by deuterium and tritium neutral beams at a total 29.5 MW. These have an inferred central alpha particle density 1.2\ifmmode\times\else\texttimes\fi{}${10}^{17}$ ${\mathrm{m}}^{\mathrm{\ensuremath{-}}3}$ without the appearance either disruptive magnetohydrodynamics events or detectable changes Alfv\'en wave activity. The measured loss rate energetic particles agreed with...
Rayleigh-Taylor instability growth is shown to be hydrodynamically scale invariant in convergent cylindrical implosions for targets that varied radial dimension and implosion timescale by a factor of 3. The were driven directly laser irradiation providing short impulse, at an embedded aluminum interface occurs as it converges radially inward 2.25 decelerates on central foam core. Late-time factors 14 are observed single-mode m=20 azimuthal perturbation both scales, despite the differences...
We present an inversion method capable of robustly unfolding MeV x-ray spectra from filter stack spectrometer (FSS) data without requiring a priori specification spectral shape or arbitrary termination the algorithm. Our is based upon perturbative minimization (PM) algorithm, which has previously been shown to be transmission data, albeit for limited regime in mass attenuation coefficient material increases monotonically with energy. improves PM algorithm through regular smoothing candidate...
Alpha-particle-driven toroidal Alfvén eigenmodes (TAEs) have been observed for the first time in deuterium-tritium (D-T) plasmas on tokamak fusion test reactor (TFTR). These modes are 100–200 ms following end of neutral beam injection with reduced central magnetic shear and elevated safety factor [q0>1]. Mode activity is localized to region discharge r/a<0.5 fluctuation level B̃⊥/B∥∼10−5 mode numbers range n=2–4, consistent theoretical calculations α-TAE stability TFTR.Received 11 November...
The relaxation of core transport barriers in TFTR enhanced reversed shear plasmas has been studied by varying the radial electric field using different applied torques from neutral beam injection. Transport rates and fluctuations remain low over a wide range shear, but increase when local $\mathbf{E}\ifmmode\times\else\texttimes\fi{}\mathbf{B}$ shearing are driven below threshold comparable to fastest linear growth dominant instabilities. Shafranov-shift-induced stabilization alone is not...
A bifurcation in the core poloidal rotation of carbon impurity ions Tokamak Fusion Test Reactor (TFTR) has been observed prior to transport associated with enhanced reverse shear plasmas. In a narrow radial region plasma, ion reverses direction. This flow is establishment large negative electric field strong shear. The measured velocities before, during, and after this precursor differ from neoclassical predictions.
The roles of turbulence stabilization by sheared E×B flow and Shafranov shift gradients are examined for Tokamak Fusion Test Reactor [D. J. Grove D. M. Meade, Nucl. 25, 1167 (1985)] enhanced reverse-shear (ERS) plasmas. Both effects in combination provide the basis a positive-feedback model that predicts reinforced suppression with increasing pressure gradient. Local fluctuation behavior at onset ERS confinement is consistent this framework. power required transitions into regime lower when...
After many years of fusion research, the conditions needed for a D–T reactor have been approached on Tokamak Fusion Test Reactor (TFTR) [Fusion Technol. 21, 1324 (1992)]. For first time unique phenomena present in plasma are now being studied laboratory plasma. The magnetic experiments to study plasmas using nearly equal concentrations deuterium and tritium carried out TFTR. At maximum power 10.7 MW, 39.5 MW neutral-beam heating, supershot discharge 6.7 high-βp following current rampdown....
First results from the analysis of neutron image data collected on implosions cryogenically layered deuterium-tritium capsules during 2011-2012 National Ignition Campaign are reported. The span a variety experimental designs aimed at increasing stagnation pressure central hotspot and areal density surrounding fuel assembly. Images neutrons produced by deuterium–tritium fusion reactions in presented, as well images that scatter dense compared with 1D 2D model predictions, consistency checked...
Indirect drive experiments have now been carried out with laser powers and energies up to 520 TW 1.9 MJ. These show that the energy coupling target is nearly constant at 84% ± 3% over a wide range of parameters from 350 1.2 Experiments depleted uranium hohlraums achieve radiation temperatures ∼330 4 eV, enough capsules 20 μm thicker than ignition point design velocities near goal 370 km/s. A series three symcap implosion identical target, laser, diagnostics configurations symmetry are...
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 Andrei N. Simakov, Douglas C. Wilson, Sunghwan A. Yi, John L. Kline, Daniel S. Clark, Jose Milovich, Jay D. Salmonson, Steven H. Batha; Optimized beryllium target design for indirectly driven inertial confinement fusion experiments on the National Ignition Facility. Phys. Plasmas 1 February 2014; 21 (2):...
The first cryogenic deuterium and deuterium-tritium liquid layer implosions at the National Ignition Facility (NIF) demonstrate D2 DT inertial confinement fusion (ICF) that can access a low-to-moderate hot-spot convergence ratio (12<CR<25). Previous ICF experiments NIF utilized high (CR>30) ice implosions. Although CR is desirable in an idealized 1D sense, it amplifies deleterious effects of asymmetries. To date, these asymmetries prevented achievement ignition are major cause...
Abstract Indirect drive converts high power laser light into x-rays using small high- Z cavities called hohlraums. X-rays generated at the hohlraum walls a capsule filled with deuterium–tritium (DT) fuel to fusion conditions. Recent experiments have produced yields exceeding 50 kJ where alpha heating provides ~3× increase in yield over PdV work. Closing gaps toward ignition is challenging, requiring optimization of target/implosions and extract maximum energy. The US program has...
Advances in target fabrication have made double shell capsule implosions a viable platform to study burning fusion plasmas. Central the is high-Z (e.g., Au) metal pusher that accesses volume-burn regime by reducing radiative losses through radiation trapping and compressing uniform fuel volume at reduced velocities. A implosion relies on series of energy transfer processes starting from x-ray absorption outer shell, followed kinetic an inner finally conversion internal energy. We present...
We examine reaction-in-flight (RIF) neutrons as diagnostics for hydrodynamical mixing of high-Z shell material into the hotspot double capsules that are designed National Ignition Facility. In particular, we consider effects different levels tungsten DT gas on RIF spectra. Using a set 1D simulations from radiation hydrodynamic code xRAGE to determine temperature and density profiles mixed W-DT gas, find increasing mass mix systematically reduces ratio primary 14 MeV neutrons. The shape...
Laser-accelerated ion beams show promise for many applications, including high-resolution flash imaging of static or dynamic objects in next-generation radiography to probe materials and plasmas extreme environments inertial confinement fusion. To scale up beam production we conducted experiments using sub-picosecond lasers 0.5 kJ at the OMEGA-EP facility characterize proton from solid targets, primarily CH/CD sub-micron thin films which were also used first time. For standalone CH films,...