Article
Physics, Fluids & Plasmas
K. D. Meaney, N. M. Hoffman, Y. Kim, H. Geppert-Kleinrath, H. W. Herrmann, C. Cerjan, O. L. Landen, B. Appelbe
Summary: In inertial confinement fusion, the timing shift of carbon gamma rays compared to DT fusion burn indicates the continuous increase of carbon areal density throughout the fusion process. Studies show that the carbon gamma ray peak arrives systematically 11 +/- 10 ps later than the DT fusion burn, possibly related to the energy balance of the implosion.
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
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
A. B. Zylstra, A. L. Kritcher, O. A. Hurricane, D. A. Callahan, J. E. Ralph, D. T. Casey, A. Pak, O. L. Landen, B. Bachmann, K. L. Baker, L. Berzak Hopkins, S. D. Bhandarkar, J. Biener, R. M. Bionta, N. W. Birge, T. Braun, T. M. Briggs, P. M. Celliers, H. Chen, C. Choate, D. S. Clark, L. Divol, T. Doppner, D. Fittinghoff, M. J. Edwards, M. Gatu Johnson, N. Gharibyan, S. Haan, K. D. Hahn, E. Hartouni, D. E. Hinkel, D. D. Ho, M. Hohenberger, J. P. Holder, H. Huang, N. Izumi, J. Jeet, O. Jones, S. M. Kerr, S. F. Khan, H. Geppert Kleinrath, V. Geppert Kleinrath, C. Kong, K. M. Lamb, S. Le Pape, N. C. Lemos, J. D. Lindl, B. J. MacGowan, A. J. Mackinnon, A. G. MacPhee, E. Marley, K. Meaney, M. Millot, A. S. Moore, K. Newman, J-M G. Di Nicola, A. Nikroo, R. Nora, P. K. Patel, N. G. Rice, M. S. Rubery, J. Sater, D. J. Schlossberg, S. M. Sepke, K. Sequoia, S. J. Shin, M. Stadermann, S. Stoupin, D. J. Strozzi, C. A. Thomas, R. Tommasini, C. Trosseille, E. R. Tubman, P. L. Volegov, C. R. Weber, C. Wild, D. T. Woods, S. T. Yang, C. Young
Summary: On August 8, 2021, an inertial fusion implosion on the National Ignition Facility achieved a fusion yield of over a megajoule and met Lawson's criterion for ignition. Experimental measurements show significant improvements in burn rate and hot-spot conditions, reaching unprecedented levels in inertial fusion research.
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, Multidisciplinary
D. T. Casey, B. J. MacGowan, J. D. Sater, A. B. Zylstra, O. L. Landen, J. Milovich, O. A. Hurricane, A. L. Kritcher, M. Hohenberger, K. Baker, S. Le Pape, T. Doppner, C. Weber, H. Huang, C. Kong, J. Biener, C. Young, S. Haan, R. C. Nora, S. Ross, H. Robey, M. Stadermann, A. Nikroo, D. A. Callahan, R. M. Bionta, K. D. Hahn, A. S. Moore, D. Schlossberg, M. Bruhn, K. Sequoia, N. Rice, M. Farrell, C. Wild
Summary: In this study, it was found that nonuniformity in the ablator shell thickness in high-density carbon experiments is a significant cause for observed 3D rho R asymmetries, leading to rho R asymmetries of approximately 25% and hot spot velocities of around 100 km/s. This work provides insight into the significant implosion performance degradation in ignition experiments and highlights the need for stringent requirements on capsule thickness metrology and symmetry.
PHYSICAL REVIEW LETTERS
(2021)
Article
Physics, Fluids & Plasmas
A. C. Hayes, G. Kyrala, M. Gooden, J. B. Wilhelmy, L. Kot, P. Volegov, C. Wilde, B. Haines, Gerard Jungman, R. S. Rundberg, D. C. Wilson, C. Velsko, W. Cassata, E. Henry, C. Yeamans, C. Cerjan, T. Ma, T. Doppner, A. Nikroo, O. Hurricane, D. Callahan, D. Hinkel, D. Schneider, B. Bachmann, F. Graziani, K. C. Chen, C. Kong, H. Huang, J. W. Crippen, M. Ratledge, N. G. Rice, M. P. Farrell
Summary: This study reports on the first experiment dedicated to studying nuclear reactions on dopants in a cryogenic capsule at the National Ignition Facility (NIF). Bromine doping in the CH ablator of a capsule, identical to one used in previous NIF shots, was used in the experiment. The results showed that the doped capsule had a DT yield 2.6 times lower than the undoped equivalent. The Radiochemical Analysis of Gaseous Samples (RAGS) system was employed to collect and detect the products of deuteron and proton ion reactions as well as knock-on deuteron reactions.
PHYSICS OF PLASMAS
(2023)
Article
Physics, Multidisciplinary
Lan Gao, B. F. Kraus, K. W. Hill, M. B. Schneider, A. Christopherson, B. Bachmann, M. Bitter, P. Efthimion, N. Pablant, R. Betti, C. Thomas, D. Thorn, A. G. MacPhee, S. Khan, R. Kauffman, D. Liedahl, H. Chen, D. Bradley, J. Kilkenny, B. Lahmann, E. Stambulchik, Y. Maron
Summary: The evolution of hot spot plasma conditions was measured using high-resolution x-ray spectroscopy. The electron density and temperature of the hot spot were determined by observing Stark broadening and dielectronic satellites in the Kr He?? spectra. The effect of dopants on the hot spot parameters was also revealed.
PHYSICAL REVIEW LETTERS
(2022)
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
Instruments & Instrumentation
M. J. Rosenberg, J. E. Hernandez, N. Butler, T. Filkins, R. E. Bahr, R. K. Jungquist, M. Bedzyk, G. Swadling, J. S. Ross, P. Michel, N. Lemos, J. Eichmiller, R. Sommers, P. Nyholm, R. Boni, J. A. Marozas, R. S. Craxton, P. W. McKenty, A. Sharma, P. B. Radha, D. H. Froula, P. Datte, J. M. Gorman, J. D. Moody, J. M. Heinmiller, J. Fornes, P. Hillyard, S. P. Regan
Summary: The Scattered Light Time-history Diagnostic (SLTD) at NIF aims to enhance measurements of scattered light in ICF experiments through an array of 15 units with different angles, collecting light in various wavelengths and with high time resolution. Current operation of six units is providing valuable data to improve models of laser energy coupling and enhance total laser energy inference in implosions.
REVIEW OF SCIENTIFIC INSTRUMENTS
(2021)
Article
Optics
Zou Lu, Geng Yuanchao, Liu Guodong, Liu Lanqin, Chen Fengdong, Liu Bingguo, Hu Dongxia, Zhou Wei, Peng Zhitao
Summary: A novel method based on ensemble deep neural networks is proposed to accurately predict the laser output energy of an inertial confinement fusion (ICF) facility. The method considers more related factors and achieves robust and stable predictions using ensemble techniques.
Article
Physics, Fluids & Plasmas
Chuanying Li, Fengjun Ge, Changshu Wu, Jianfa Gu, Zhongjing Chen, Zhensheng Dai, Xin Li, Tianxuan Huang, Bolun Chen, Bo Deng, Keli Deng, Wudi Zheng, Shiyang Zou
Summary: Achieving ignition requires understanding and controlling time-dependent implosion asymmetry. A recent experiment demonstrated effective time-dependent symmetry control by modifying the ratio of inner beam power to outer beam power. Analysis of hohlraum radiation and P2 drive asymmetry illustrated the sensitivity of P2 shell asymmetry to drive asymmetry.
PHYSICS OF PLASMAS
(2021)
Article
Physics, Fluids & Plasmas
Hui Cao, Xufei Xie, Yaohua Chen, Yunsong Dong, Liquan Wang, Zhurong Cao, Xu Chen, Qiangqiang Wang, Wei Zhou, Wei Zhang, Zhichao Li, Sanwei Li, Bo Deng, Liang Hao, Shu Li, Junfeng Wu, Guoli Ren, Xudeng Hang, Wenyi Huo, Xiaoxia Huang, Xiaoshi Peng, Dong Yang, Tao Xu, Lifei Hou, Xingsen Che, Liang Guo, Huabing Du, Xiaoan He, Chaoguang Li, Pin Yang, Qianqian Gu, Yuancheng Wang, Kuixing Zheng, Yunbao Huang, Bin Feng, Guanghui Yuan, Baibin Jiang, Haijun Zhang, Feng Wang, Jiamin Yang, Shenye Liu, Jun Xie, Zhibing He, Kai Du, Jie Liu, Shiyang Zou, Yongkun Ding, Qihua Zhu, Ke Lan
Summary: The novel octahedral spherical hohlraum is a promising approach for the next generation of laser systems to achieve predictable and reproducible fusion gain. Repointing the laser beams at a cylindrically configured laser facility can approach the ideal octahedral beam configuration. The investigation and experiment at the SGIII facility showed the feasibility of the 32-beam optimum repointing scheme and demonstrated the generation of high energy inside an octahedral hohlraum.
PHYSICS OF PLASMAS
(2023)
Article
Instruments & Instrumentation
Andrew G. MacPhee, Perry M. Bell, Dusty Boyle, Arthur C. Carpenter, Liam Claus, Matthew Dayton, Jack Dean, Anthony K. L. Dymoke-Bradshaw, Cassandra Durand, Brad Funsten, Anne Garafalo, Brad P. Golick, Jonathan D. Hares, Jeremy Hill, Justin M. Kehl, Shahab F. Khan, J. D. Kilkenny, Mike J. MacDonald, Devon Maheshwari, Ian J. Mccubbin, Sabrina R. Nagel, Peter R. Nyholm, Nathan E. Palmer, Robert B. Petre, Marcos Sanchez, Marilyn B. Schneider, Markus O. Schoelmerich, Stanislav Stoupin, Adrianne Welton
Summary: This article presents a radiation-hardened x-ray streak camera for recording the time-resolved bremsstrahlung spectrum from the core of an inertial confinement fusion implosion. Preliminary results from the first experiment show that the camera records the spectrum at more than 40 times the operational neutron yield limit of previous cameras.
REVIEW OF SCIENTIFIC INSTRUMENTS
(2022)
Article
Instruments & Instrumentation
S. F. Khan, D. A. Martinez, D. H. Kalantar, R. K. Kirkwood, C. Santos, N. A. Ose, S. Johnson, D. A. Alessi, M. A. Prantil, D. T. Woods, S. G. Glendinning, R. Tommasini, A. J. Mackinnon, S. T. Prisbrey, T. R. Dittrich, M. W. Bowers, J. Cabral, J. Crane, J. -M. Di Nicola, M. Hamamoto, S. Herriot, T. Lanier, R. Lowe-Webb, L. J. Pelz, C. C. Widmayer, W. Williams, S. Yang
Summary: Researchers have developed a new imaging platform to study the behavior of matter at extreme densities and pressures, utilizing micro-wires irradiated by a short pulse laser system and inferring characteristics of the back-lighter source using a forward-fitting algorithm for system resolution. This imaging technique can be adapted to most point-projection platforms where resolution, spectral contrast, and signal-to-noise are important.
REVIEW OF SCIENTIFIC INSTRUMENTS
(2021)
Article
Physics, Fluids & Plasmas
John D. D. Lindl, Steven W. W. Haan, Otto L. L. Landen
Summary: This study extends the evaluation of ignition metrics to consider the effect of hohlraum cooling before peak implosion velocity in radiation-driven implosions. Firstly, the authors present an extension of the results for key hot spot stagnation quantities from a previous study, showing that modified analytic expressions match the experimental results for implosions with and without hohlraum cooling. Secondly, the authors compare the radiation hydrodynamics simulations with an analytic piston model to investigate the sensitivity of hohlraum cooling time and shell radius at peak velocity. Thirdly, they provide a set of ignition metrics that are applicable to a wide range of capsule designs with or without hohlraum cooling before peak implosion velocity.
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
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
Physics, Fluids & Plasmas
V. Geppert-Kleinrath, N. Hoffman, N. Birge, A. DeYoung, D. Fittinghoff, M. Freeman, H. Geppert-Kleinrath, Y. Kim, K. Meaney, G. Morgan, M. Rubery, L. Tafoya, C. Wilde, P. Volegov
Summary: The joint LANL/LLNL nuclear imaging team has successfully obtained gamma-ray images of inertial confinement fusion implosions at the National Ignition Facility. These images provide crucial and difficult-to-acquire information about the confined fuel and ablator assembly. Gamma imaging reveals both direct emission of gamma radiation from DT fusion reactions and gamma rays produced when DT fusion neutrons scatter on carbon nuclei in the remaining ablator.
PHYSICS OF PLASMAS
(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, Multidisciplinary
A. Pak, L. Divol, D. T. Casey, S. F. Khan, A. L. Kritcher, J. E. Ralph, R. Tommasini, C. Trosseille, A. B. Zylstra, K. L. Baker, N. W. Birge, R. Bionta, B. Bachmann, E. L. Dewald, T. Doeppner, M. S. Freeman, D. N. Fittinghoff, V. Geppert-Kleinrath, H. Geppert-Kleinrath, K. D. Hahn, M. Hohenberger, J. Holder, S. Kerr, Y. Kim, B. Kozioziemski, K. Lamb, B. J. MacGowan, A. G. MacPhee, K. D. Meaney, A. S. Moore, D. J. Schlossberg, S. Stoupin, P. Volegov, C. Wilde, C. V. Young, O. L. Landen, R. P. J. Town
Summary: The quantification of various parameters in experiments on inertially confined fusion plasmas with target gains up to 0.72 reveals that increased rates of self-heating initially compensate for expansion power losses. As target gain rises, reacting plasmas reach peak fusion production at later times with increased size, temperature, mass, and lower emission weighted areal densities. Analytical models support these observations and provide insights into the evolution of these variables.
PHYSICAL REVIEW LETTERS
(2023)
Article
Physics, Fluids & Plasmas
K. L. Baker, P. A. Amendt, J. S. Ross, V. A. Smalyuk, O. L. Landen, D. D. Ho, S. Khan, S. W. Haan, J. D. Lindl, D. Mariscal, J. L. Milovich, S. Maclaren, Y. Ping, D. J. Strozzi, R. M. Bionta, D. T. Casey, P. M. Celliers, D. N. Fittinghoff, H. Geppert-Kleinrath, V. Geppert-Kleinrath, K. D. Hahn, M. Gatu Johnson, Y. Kim, K. Meaney, M. Millot, R. Nora, P. L. Volegov, C. H. Wilde
Summary: This study reports on indirect-drive implosions driven by a dual conical frustum-shaped hohlraum called frustraum and the tuning campaigns leading up to two layered implosions. The results suggest that increasing the energy absorbed by the capsule at the expense of long coast times makes it more challenging to achieve ignition, and that further reducing coast time is warranted to improve the areal density and make ignition easier to achieve.
PHYSICS OF PLASMAS
(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)