Article
Physics, Fluids & Plasmas
K. L. Baker, S. MacLaren, O. Jones, B. K. Spears, P. K. Patel, R. Nora, L. Divol, O. L. Landen, G. J. Anderson, J. Gaffney, M. Kruse, O. A. Hurricane, D. A. Callahan, A. R. Christopherson, J. Salmonson, E. P. Hartouni, T. Doppner, E. Dewald, R. Tommasini, C. A. Thomas, C. Weber, D. Clark, D. T. Casey, M. Hohenberger, S. Khan, T. Woods, J. L. Milovich, R. L. Berger, D. Strozzi, A. Kritcher, B. Bachmann, R. Benedetti, R. Bionta, P. M. Celliers, D. Fittinghoff, R. Hatarik, N. Izumi, M. Gatu Johnson, G. Kyrala, T. Ma, K. Meaney, M. Millot, S. R. Nagel, A. Pak, P. L. Volegov, C. Yeamans, C. Wilde
Summary: In order to understand the proximity to ignition of current layered implosions in indirect-drive inertial confinement fusion, the level of alpha heating present needs to be measured. Experimental validation of current simulation-based methods of determining yield amplification was conducted through paired experiments, consisting of low-yield tritium-hydrogen-deuterium (THD) layered implosion and high-yield deuterium-tritium (DT) layered implosion. The THD capsules were designed to reduce DT neutron yield (alpha heating) while maintaining hydrodynamic similarity with the higher yield DT capsules. The measured yield ratio in these experiments allowed the determination of the alpha heating level in the DT layered implosions.
Article
Physics, Multidisciplinary
Alexandre Do, Christopher R. Weber, Eduard L. Dewald, Daniel T. Casey, Daniel S. Clark, Shahab F. Khan, Otto L. Landen, Andrew G. MacPhee, Vladimir A. Smalyuk
Summary: In indirect-drive inertial confinement fusion experiments, a gentle acceleration of the interface between the capsule ablator and the DT fuel can reduce hydrodynamic instability growth, resulting in improved experimental results.
PHYSICAL REVIEW LETTERS
(2022)
Article
Physics, Fluids & Plasmas
K. L. Baker, O. Jones, C. Weber, D. Clark, P. K. Patel, C. A. Thomas, O. L. Landen, R. Nora, G. J. Anderson, J. Gaffney, S. MacLaren, D. T. Casey, T. Doppner, E. L. Dewald, R. Tommasini, B. K. Spears, J. Salmonson, M. Hohenberger, S. Khan, A. Zylstra, A. Kritcher, P. Amendt, V Smalyuk, J. Lindl, C. Young, J. S. Ross, D. Ho, O. A. Hurricane, D. A. Callahan, T. Woods, J. L. Milovich, D. J. Strozzi, B. Bachmann, R. Bionta, P. M. Celliers, D. Fittinghoff, R. Hatarik, M. Gatu Johnson, K. Meaney, M. Millot, P. L. Volegov, C. Wilde
Summary: The laser-based National Ignition Facility aims to increase the fusion energy yield in inertial confinement fusion experiments by hydrodynamic scaling. This method increases the implosion scale to improve hotspot areal density and confinement time. Experimental results validate the effectiveness of hydrodynamic scaling.
PHYSICS OF PLASMAS
(2022)
Article
Physics, Fluids & Plasmas
O. L. Landen, J. D. Lindl, S. W. Haan, D. T. Casey, P. M. Celliers, D. N. Fittinghoff, N. Gharibyan, V. N. Goncharov, G. P. Grim, E. P. Hartouni, O. A. Hurricane, B. J. MacGowan, S. A. MacLaren, K. D. Meaney, M. Millot, J. L. Milovich, P. K. Patel, H. S. Robey, P. T. Springer, P. L. Volegov, M. J. Edwards
Summary: Through compression experiments and simulations, the study explores the impact of fuel convergence on ignition efficiency, finding that the strength of the first shock is the primary factor in setting the maximum fuel convergence. Additional sensitivities to successive shock strengths and fuel aspect ratios were also observed.
PHYSICS OF PLASMAS
(2021)
Article
Physics, Fluids & Plasmas
H. Sio, J. D. Moody, B. B. Pollock, D. J. Strozzi, D. D. M. Ho, C. A. Walsh, G. E. Kemp, B. Lahmann, S. O. Kucheyev, B. Kozioziemski, E. G. Carroll, J. Kroll, D. K. Yanagisawa, J. Angus, B. Bachmann, A. A. Baker, L. B. Bayu Aji, S. D. Bhandarkar, J. D. Bude, L. Divol, A. M. Engwall, B. Ferguson, J. Fry, L. Hagler, E. Hartouni, M. C. Herrmann, W. Hsing, D. M. Holunga, J. Javedani, A. Johnson, S. Khan, D. Kalantar, T. Kohut, B. G. Logan, N. Masters, A. Nikroo, N. Izumi, N. Orsi, K. Piston, C. Provencher, A. Rowe, J. Sater, S. J. Shin, K. Skulina, W. A. Stygar, V. Tang, S. E. Winters, G. Zimmerman, J. P. Chittenden, B. Appelbe, A. Boxall, A. Crilly, S. O'Neill, D. Barnak, J. Davies, J. Peebles, J. H. Bae, K. Clark, M. Havre, M. Mauldin, M. Ratledge, S. Vonhof, P. Adrian, B. Reichelt, S. Fujioka, M. Fraenkel
Summary: Magneto-inertial confinement fusion experiments on the National Ignition Facility have shown increased neutron yield and hot-spot temperature with the application of a magnetic field. A room-temperature, magnetized indirect-drive ICF platform using a high-Z, high-resistivity AuTa4 alloy as the hohlraum wall material was developed. The experiments exhibited significant improvements in performance with both 12-T and 26-T magnetic fields.
PHYSICS OF PLASMAS
(2023)
Article
Optics
Fuyuan Wu, Xiaohu Yang, Yanyun Ma, Qi Zhang, Zhe Zhang, Xiaohui Yuan, Hao Liu, Zhengdong Liu, Jiayong Zhong, Jian Zheng, Yutong Li, Jie Zhang
Summary: This paper proposes an efficient intelligent method for laser pulse optimization using genetic algorithm and random forest algorithm guided hydrodynamic simulations. It is able to significantly improve areal density and reduce in-flight-aspect ratio, and a relationship between maximum areal density and ion temperature is achieved through analysis of a large simulation dataset.
HIGH POWER LASER SCIENCE AND ENGINEERING
(2022)
Article
Optics
Tao Tao, Guannan Zheng, Qing Jia, Rui Yan, Jian Zheng
Summary: Pulse shaping is a powerful tool for mitigating implosion instabilities in direct-drive inertial confinement fusion (ICF). In this research, a machine-learning pulse shape designer is developed to achieve high compression density and stable implosion. The designer considers the facility-specific laser imprint pattern in the optimization, making the pulse design more relevant. Simulation results show that the optimized pulse increases the areal density expectation by 16% in one dimension and the clean-fuel thickness by a factor of four in two dimensions. This pulse shape designer could be a useful tool for direct-drive ICF instability control.
HIGH POWER LASER SCIENCE AND ENGINEERING
(2023)
Article
Instruments & Instrumentation
S. Stoupin, A. G. Macphee, B. Kozioziemski, M. J. Macdonald, N. Ose, J. M. Heinmiller, N. Izumi, D. Rusby, P. T. Springer, M. B. Schneider
Summary: This article describes a methodology for measuring x-ray continuum spectra of inertial confinement fusion (ICF) implosions using a high-throughput spectrometer called ConSpec. The method has been improved to enhance measurement accuracy and has been applied in the analysis of ConSpec data from different experiments. The results show good agreement between the measured spectra and the theoretical expectations, confirming the accuracy of this measurement method.
REVIEW OF SCIENTIFIC INSTRUMENTS
(2023)
Article
Physics, Fluids & Plasmas
Brian M. Haines, J. P. Sauppe, P. A. Keiter, E. N. Loomis, T. Morrow, D. S. Montgomery, L. Kuettner, B. M. Patterson, T. E. Quintana, J. Field, M. Millot, P. Celliers, D. C. Wilson, H. F. Robey, R. F. Sacks, D. J. Stark, C. Krauland, M. Rubery
Summary: Double shell capsule implosions are an alternative approach to achieve alpha heating, but current machining techniques and features introduce asymmetries and jetting that need to be controlled. To achieve high yields, these features and sensitivity to RTI must be mitigated. Due to uncertainties in computational models and high costs, computational modeling must be constrained by experiments.
PHYSICS OF PLASMAS
(2021)
Article
Physics, Multidisciplinary
D. J. Schlossberg, G. P. Grim, D. T. Casey, A. S. Moore, R. Nora, B. Bachmann, L. R. Benedetti, R. M. Bionta, M. J. Eckart, J. E. Field, D. N. Fittinghoff, M. Gatu Johnson, V Geppert-Kleinrath, E. P. Hartouni, R. Hatarik, W. W. Hsing, L. C. Jarrott, S. F. Khan, J. D. Kilkenny, O. L. Landen, B. J. MacGowan, A. J. Mackinnon, K. D. Meaney, D. H. Munro, S. R. Nagel, A. Pak, P. K. Patel, B. K. Spears, P. L. Volegov, C. Young
Summary: Experimental results show that intentionally varying the drive imbalance in inertial confinement fusion implosions can lead to decreased neutron yields and increased anisotropic neutron Doppler broadening, in agreement with simulations. Additionally, a tracer jet from the capsule fill-tube perturbation confirms the average flow speeds deduced from neutron spectroscopy.
PHYSICAL REVIEW LETTERS
(2021)
Article
Nuclear Science & Technology
J. D. Moody, B. B. Pollock, H. Sio, D. J. Strozzi, D. D. -M. Ho, C. Walsh, G. E. Kemp, S. O. Kucheyev, B. Kozioziemski, E. G. Carroll, J. Kroll, D. K. Yanagisawa, J. Angus, S. D. Bhandarkar, J. D. Bude, L. Divol, B. Ferguson, J. Fry, L. Hagler, E. Hartouni, M. C. Herrmann, W. Hsing, D. M. Holunga, J. Javedani, A. Johnson, D. Kalantar, T. Kohut, B. G. Logan, N. Masters, A. Nikroo, N. Orsi, K. Piston, C. Provencher, A. Rowe, J. Sater, K. Skulina, W. A. Stygar, V. Tang, S. E. Winters, J. P. Chittenden, B. Appelbe, A. Boxall, A. Crilly, S. O'Neill, J. Davies, J. Peebles, S. Fujioka
Summary: A new project is underway at the National Ignition Facility to apply a seed magnetic field to fusion fuel in order to enhance hot-spot temperature, shape, and neutron yield. This project entails significant scientific and technological challenges.
JOURNAL OF FUSION ENERGY
(2022)
Article
Physics, Multidisciplinary
J. D. Moody, B. B. Pollock, H. Sio, D. J. Strozzi, D. D-M Ho, C. A. Walsh, G. E. Kemp, B. Lahmann, S. O. Kucheyev, B. Kozioziemski, E. G. Carroll, J. Kroll, D. K. Yanagisawa, J. Angus, B. Bachmann, S. D. Bhandarkar, J. D. Bude, L. Divol, B. Ferguson, J. Fry, L. Hagler, E. Hartouni, M. C. Herrmann, W. Hsing, D. M. Holunga, N. Izumi, J. Javedani, A. Johnson, S. Khan, D. Kalantar, T. Kohut, B. G. Logan, N. Masters, A. Nikroo, N. Orsi, K. Piston, C. Provencher, A. Rowe, J. Sater, K. Skulina, W. A. Stygar, V Tang, S. E. Winters, G. Zimmerman, P. Adrian, J. P. Chittenden, B. Appelbe, A. Boxall, A. Crilly, S. O'Neill, J. Davies, J. Peebles, S. Fujioka
Summary: The application of an external 26 Tesla axial magnetic field to a D-2 gas-filled capsule on the National Ignition Facility leads to a significant increase in ion temperature and neutron yield, approaching the conditions required for fusion ignition. The improvements are determined through energy spectral measurements and neutron reaction estimations, and are consistent with radiation magnetohydrodynamic simulations.
PHYSICAL REVIEW LETTERS
(2022)
Article
Mechanics
Jizhou Zhang, Mengxiang Zhou, Fuwu Yan, Chao Yu, Yu Wang
Summary: Counterflow flames are used to study flame and fuel properties. The 1D modeling of counterflow flames is computationally more efficient and this study investigated its performance by comparing it with experimental measurements and 2D models. The study focused on the effects of inlet flow uniformities, which are difficult to achieve in experiments. It was found that specifying actual velocity boundary conditions is important for accurate 1D modeling.
Article
Multidisciplinary Sciences
R. W. Paddock, H. Martin, R. T. Ruskov, R. H. H. Scott, W. Garbett, B. M. Haines, A. B. Zylstra, R. Aboushelbaya, M. W. Mayr, B. T. Spiers, R. H. W. Wang, P. A. Norreys
Summary: The study investigates the performance of direct-drive implosions using liquid layer capsules at different energy levels, showing potential gains in various scale systems and achieving reactor-level gains for an 8.5MJ implosion. This low-instability regime presents a new approach to fusion energy and warrants further investigation.
PHILOSOPHICAL TRANSACTIONS OF THE ROYAL SOCIETY A-MATHEMATICAL PHYSICAL AND ENGINEERING SCIENCES
(2021)
Article
Physics, Fluids & Plasmas
A. A. Solodov, M. J. Rosenberg, M. Stoeckl, A. R. Christopherson, R. Betti, P. B. Radha, C. Stoeckl, M. Hohenberger, B. Bachmann, R. Epstein, R. K. Follett, W. Seka, J. F. Myatt, P. Michel, S. P. Regan, J. P. Palastro, D. H. Froula, E. M. Campbell, V. N. Goncharov
Summary: Experiments on the NIF have shown that adding a silicon layer in the ablator can mitigate the growth of laser-plasma instabilities and reduce target preheat, providing a promising path forward for direct-drive inertial confinement fusion ignition designs.
Article
Physics, Multidisciplinary
E. P. Hartouni, A. S. Moore, A. J. Crilly, B. D. Appelbe, P. A. Amendt, K. L. Baker, D. T. Casey, D. S. Clark, T. Doppner, M. J. Eckart, J. E. Field, M. Gatu-Johnson, G. P. Grim, R. Hatarik, J. Jeet, S. M. Kerr, J. Kilkenny, A. L. Kritcher, K. D. Meaney, J. L. Milovich, D. H. Munro, R. C. Nora, A. E. Pak, J. E. Ralph, H. F. Robey, J. S. Ross, D. J. Schlossberg, S. M. Sepke, B. K. Spears, C. Young, A. B. Zylstra
Summary: Inertial confinement fusion experiments at the National Ignition Facility aim to achieve sustained thermonuclear burn for energy generation. This study investigates the departure from hydrodynamic behavior when fusion reactions become the primary source of plasma heating. The relationship between ion temperature and mean ion kinetic energy is analyzed using neutron spectrum moments.
Article
Physics, Fluids & Plasmas
S. M. Kerr, D. Rusby, G. J. Williams, K. Meaney, D. J. Schlossberg, A. Aghedo, D. Alessi, J. Ayers, S. Azhar, M. B. Aufderheide, M. W. Bowers, J. D. Bude, H. Chen, G. Cochran, J. Crane, J. M. Di Nicola, D. N. Fittinghoff, P. Fitzsimmons, H. Geppert-Kleinrath, B. Golick, G. P. Grim, A. Haid, M. Hamamoto, R. Heredia, M. Hermann, S. Herriot, M. P. Hill, W. Hoke, D. Kalantar, A. Kemp, Y. Kim, K. LaFortune, N. Lemos, A. Link, R. Lowe-Webb, A. MacPhee, M. Manuel, D. Martinez, M. Mauldin, S. Patankar, L. Pelz, M. A. Prantil, M. Quinn, C. W. Siders, S. Vonhof, P. Wegner, S. Wilks, W. Williams, K. Youngblood, A. J. Mackinnon
Summary: Compound parabolic concentrators (CPCs) are used in the National Ignition Facility Advanced Radiographic Capability (NIF-ARC) laser to enhance electron acceleration and high energy photon production. CPC targets show significant improvement in mean electron energy (>2x) and photon brightness (>10x) compared to flat targets. Photon spectra are characterized for E-photon = 0.5 - 30 MeV using multiple diagnostic techniques, and beam width and pointing variations are provided. Efficient production of MeV photons with doses exceeding 10 rad in air at 1 m for E-photon > 0.5 MeV is observed with CPCs at I-laser asymptotic to 2 x 10^(18) W/cm(2). Promising results are achieved for the development of bright MeV x-ray and particle sources on Petawatt class laser systems. Published under an exclusive license by AIP Publishing.
PHYSICS OF PLASMAS
(2023)
Article
Instruments & Instrumentation
M. O. Schoelmerich, T. Doppner, C. H. Allen, L. Divol, M. Oliver, D. Haden, M. Biener, J. Crippen, J. Delora-Ellefson, B. Ferguson, D. O. Gericke, A. Goldman, A. Haid, C. Heinbockel, D. Kalantar, Z. Karmiol, G. Kemp, J. Kroll, O. L. Landen, N. Masters, Y. Ping, C. Spindloe, W. Theobald, T. G. White
Summary: A designed x-ray Fresnel diffractive radiography platform is used to measure micron-scale changes in density gradients across materials at the National Ignition Facility. This platform uses 4.75 keV Ti K-shell x-ray emission to heat a plastic cylinder with liquid D-2, allowing for precise tracking of density gradient changes. By using Cu He-alpha x rays and a narrow slit aperture, significant diffraction features are observed, enhancing the sensitivity to density scale length changes at the material interface.
REVIEW OF SCIENTIFIC INSTRUMENTS
(2023)
Article
Physics, Multidisciplinary
Daniel T. Casey, Chris R. Weber, Alex B. Zylstra, Charlie J. Cerjan, Ed Hartouni, Matthias Hohenberger, Laurent Divol, David S. Dearborn, Neel Kabadi, Brandon Lahmann, Maria Gatu Johnson, Johan A. Frenje
Summary: The enhancement of fusion reaction rates by electron screening is an important plasma-nuclear effect but has not been experimentally observed. Experiments using inertial confinement fusion (ICF) implosions may provide an opportunity to observe this effect. The experiments at the National Ignition Facility (NIF) have reached the relevant physical regime, but the expected impacts of plasma screening on nuclear reaction rates are currently too small and need to be increased. This work lays the foundation for future efforts to develop a platform capable of observing plasma electron screening.
FRONTIERS IN PHYSICS
(2023)
Article
Multidisciplinary Sciences
T. Doppner, M. Bethkenhagen, D. Kraus, P. Neumayer, D. A. Chapman, B. Bachmann, R. A. Baggott, M. P. Bohme, L. Divol, R. W. Falcone, L. B. Fletcher, O. L. Landen, M. J. MacDonald, A. M. Saunders, M. Schorner, P. A. Sterne, J. Vorberger, B. B. L. Witte, A. Yi, R. Redmer, S. H. Glenzer, D. O. Gericke
Summary: This article reports on an experiment that creates and diagnoses matter at pressures exceeding three gigabars. The experiment shows the presence of quantum-degenerate electrons and strongly reduced elastic scattering under extreme conditions.
Article
Physics, Fluids & Plasmas
N. Izumi, T. Doppner, J. L. Milovich, O. L. Landen, D. A. Callahan, T. Chapman, D. E. Hinkel, C. V. Houldin Hatala, S. Khan, J. J. Kroll, B. J. MacGowan, E. Marin, D. Mariscal, M. Mauldin, M. Millot, J. D. Moody, K. Newman, M. Ratledge, J. S. Ross, E. Tubman, S. Vonhof, J. Wall
Summary: Through optimized pulse shaping, beam pointing, and temporal phasing, a symmetric implosion using a 14-ns low-adiabat drive pulse is possible in a low backscatter loss 0.45mg/cc He-filled Hohlraum. The ingress of the Hohlraum walls was mitigated by revisiting the adiabat-shaped design. Low-mode P-2 and P-4 drive asymmetry swings caused by the drift of the laser spots were essentially zeroed out by employing temporal beam phasing between cones of beams. The results also indicate an improved coupling efficiency and pave the way for revisiting low-adiabat, high convergence drives using CH ablators.
PHYSICS OF PLASMAS
(2023)
Article
Physics, Fluids & Plasmas
K. L. Baker, C. A. Thomas, O. L. Landen, S. Haan, J. D. Lindl, D. T. Casey, C. Young, R. Nora, O. A. Hurricane, D. A. Callahan, O. Jones, L. Berzak Hopkins, S. Khan, B. K. Spears, S. Le Pape, N. B. Meezan, D. D. Ho, T. Doppner, D. Hinkel, E. L. Dewald, R. Tommasini, M. Hohenberger, C. Weber, D. Clark, D. T. Woods, J. L. Milovich, D. Strozzi, A. Kritcher, H. F. Robey, J. S. Ross, V. A. Smalyuk, P. A. Amendt, B. Bachmann, L. R. Benedetti, R. Bionta, P. M. Celliers, D. Fittinghoff, C. Goyon, R. Hatarik, N. Izumi, M. Gatu Johnson, G. Kyrala, T. Ma, K. Meaney, M. Millot, S. R. Nagel, P. K. Patel, D. Turnbull, P. L. Volegov, C. Yeamans, C. Wilde
Summary: In indirect-drive implosions, increasing laser peak power and radiation drive temperature can improve the core hot spot energy, pressure, and neutron yield. This improvement has been quantified and explained by simple analytic scalings validated by 1D simulations. Extrapolating from existing data, it is possible to achieve a yield of 2-3x10^17 (0.5-0.7 MJ) using only 1.8 MJ of laser energy in a low gas-fill 5.4 mm diameter Hohlraum at the 500 TW National Ignition Facility peak power limit.
PHYSICS OF PLASMAS
(2023)
Article
Instruments & Instrumentation
B. Reichelt, N. Kabadi, J. Pearcy, M. Gatu Johnson, S. Dannhoff, B. Lahmann, J. Frenje, C. K. Li, G. Sutcliffe, J. Kunimune, R. Petrasso, H. Sio, A. Moore, E. Mariscal, E. Hartouni
Summary: This paper develops a process to determine the x-ray sensitivity of PTOF detectors and relates it to the intrinsic properties of the detector. It is demonstrated that the diamond sample has significant non-homogeneity and the charge collection can be described by a linear model ax + b, where a = 0.63 +/- 0.16 V-1 mm(-1) and b = 0.00 +/- 0.04 V-1. The electron to hole mobility ratio is confirmed to be 1.5 +/- 1.0 and the effective bandgap is 1.8 eV, leading to an increased sensitivity.
REVIEW OF SCIENTIFIC INSTRUMENTS
(2023)
Review
Instruments & Instrumentation
M. Gatu Johnson
Summary: MeV-range ions generated in ICF and high-energy-density physics experiments carry important information, such as fusion reaction yield, implosion areal density, electron temperature, and electric and magnetic fields. This paper reviews the principles of obtaining this information from data and describes the charged particle diagnostic suite available at major US ICF facilities. It discusses time-integrating instruments, time-resolving detectors, and charged-particle radiography setups for measuring ion emission and probing plasma experiments.
REVIEW OF SCIENTIFIC INSTRUMENTS
(2023)
Review
Instruments & Instrumentation
A. S. Moore, D. J. Schlossberg, B. D. Appelbe, G. A. Chandler, A. J. Crilly, M. J. Eckart, C. J. Forrest, V. Y. Glebov, G. P. Grim, E. P. Hartouni, R. Hatarik, S. M. Kerr, J. Kilkenny, J. P. Knauer
Summary: Neutrons generated in Inertial Confinement Fusion (ICF) experiments provide valuable information about the plasma conditions. The neutron time-of-flight (nToF) technique is utilized to measure the neutron energy spectrum due to the short emission time in ICF experiments. By placing detectors several meters away from the source, the neutron energy spectrum can be measured with high precision. We review the current state of nToF detectors at ICF facilities in the United States, including the measured physics, deployed detector technologies, and analysis techniques used.
REVIEW OF SCIENTIFIC INSTRUMENTS
(2023)
Article
Physics, Multidisciplinary
S. Jiang, O. L. Landen, H. D. Whitley, S. Hamel, R. London, D. S. Clark, P. Sterne, S. B. Hansen, S. X. Hu, G. W. Collins, Y. Ping
Summary: Transport properties of high energy density matter play a crucial role in the evolution of various systems. In this study, we propose an experimental platform utilizing x-ray differential heating and time-resolved refraction-enhanced radiography coupled with a deep neural network to overcome the uncertainties in the warm dense matter regime. We successfully measure the thermal conductivity of CH and Be in this regime and find discrepancies with existing models, suggesting the need for improvement in transport models to enhance the understanding of inertial confinement fusion.
COMMUNICATIONS PHYSICS
(2023)
Article
Physics, Fluids & Plasmas
C. R. Weber, D. S. Clark, D. T. Casey, G. N. Hall, O. Jones, O. Landen, A. Pak, V. A. Smalyuk
Summary: In inertial confinement fusion (ICF) implosions, the interface between the cryogenic DT fuel and the ablator is unstable to shock acceleration and constant acceleration. The Rayleigh-Taylor instability (RT) can produce oscillatory motion that stabilizes against the Richtmyer-Meshkov instability (RM) if the constant acceleration is in the direction of lighter material. This characteristic is now being incorporated into newer designs to improve compression while minimizing ablator mixing into the fuel.
Article
Physics, Fluids & Plasmas
K. L. Baker, S. MacLaren, O. Jones, B. K. Spears, P. K. Patel, R. Nora, L. Divol, O. L. Landen, G. J. Anderson, J. Gaffney, M. Kruse, O. A. Hurricane, D. A. Callahan, A. R. Christopherson, J. Salmonson, E. P. Hartouni, T. Doppner, E. Dewald, R. Tommasini, C. A. Thomas, C. Weber, D. Clark, D. T. Casey, M. Hohenberger, S. Khan, T. Woods, J. L. Milovich, R. L. Berger, D. Strozzi, A. Kritcher, B. Bachmann, R. Benedetti, R. Bionta, P. M. Celliers, D. Fittinghoff, R. Hatarik, N. Izumi, M. Gatu Johnson, G. Kyrala, T. Ma, K. Meaney, M. Millot, S. R. Nagel, A. Pak, P. L. Volegov, C. Yeamans, C. Wilde
Summary: In order to understand the proximity to ignition of current layered implosions in indirect-drive inertial confinement fusion, the level of alpha heating present needs to be measured. Experimental validation of current simulation-based methods of determining yield amplification was conducted through paired experiments, consisting of low-yield tritium-hydrogen-deuterium (THD) layered implosion and high-yield deuterium-tritium (DT) layered implosion. The THD capsules were designed to reduce DT neutron yield (alpha heating) while maintaining hydrodynamic similarity with the higher yield DT capsules. The measured yield ratio in these experiments allowed the determination of the alpha heating level in the DT layered implosions.
Article
Physics, Fluids & Plasmas
A. Do, D. T. Casey, D. S. Clark, B. Bachmann, K. L. Baker, T. Braun, T. M. Briggs, T. D. Chapman, P. M. Celliers, H. Chen, C. Choate, E. L. Dewald, L. Divol, G. Fathi, D. N. Fittinghoff, G. N. Hall, E. Hartouni, D. M. Holunga, S. F. Khan, A. L. Kritcher, O. L. Landen, A. G. Macphee, M. Millot, E. V. Marley, J. L. Milovich, A. Nikroo, A. E. Pak, D. J. Schlossberg, V. A. Smalyuk, M. Stadermann, D. J. Strozzi, R. Tommasini, C. R. Weber, B. N. Woodworth, D. K. Yanagisawa, N. W. Birge, C. R. Danly, M. Durocher, M. S. Freeman, H. Geppert-Kleinrath, V. Geppert-Kleinrath, Y. Kim, K. D. Meaney, C. H. Wilde, M. Gatu Johnson, A. Allen, M. Ratledge, C. Kong, T. Fehrenbach, C. Wild
Summary: This article examines the improvement of compression in high-density carbon-based ablators by reducing hydrodynamic growth of perturbations. Through experiments with different pulse shapes and ablators distribution, the study evaluates implosion symmetry, laser backscatter, stability, and compression. The research demonstrates improved compression has been achieved.
PHYSICS OF PLASMAS
(2023)