Two-dimensional simulations of the neutron yield in cryogenic deuterium-tritium implosions on OMEGA

Hu, S. X.; Goncharov, V. N.; Radha, P. B.; Marozas, J. A.; Skupsky, S.; Boehly, T. R.; Sangster, T. C.; Meyerhofer, D. D.; McCrory, R. L.
October 2010
Physics of Plasmas;Oct2010, Vol. 17 Issue 10, p102706
Academic Journal
Maximizing the neutron yield to obtain energy gain is the ultimate goal for inertial confinement fusion. Nonuniformities seeded by target and laser perturbations can disrupt neutron production via the Rayleigh-Taylor instability growth. To understand the effects of perturbations on the neutron yield of cryogenic DT implosions on the Omega Laser Facility [T. R. Boehly et al., Opt. Commun. 133, 495 (1997)], two-dimensional DRACO [P. B. Radha et al., Phys. Plasmas 12, 056307 (2005)] simulations have been performed to systematically investigate each perturbation source and their combined effects on the neutron-yield performance. Two sources of nonuniformity accounted for the neutron-yield reduction in DRACO simulations: target offset from the target chamber center and laser imprinting. The integrated simulations for individual shots reproduce the experimental yield-over-clean (YOC) ratio within a factor of 2 or better. The simulated neutron-averaged ion temperatures is only about 10%-15% higher than measurements. By defining the temperature-over-clean, its relationship to YOC provides an indication of how much the hot-spot volume and density are perturbed with respect to the uniform situation. Typically, the YOC in OMEGA experiments is of the order of ∼5%. The simulation results suggest that YOC can be increased to the ignition hydroequivalent level of 15%-20% (with <ρR>=200-300 mg/cm2) by maintaining a target offset of less than 10 μm and employing beam smoothing by spectral dispersion.


Related Articles

  • Cryogenic DT and D2 targets for inertial confinement fusion. Sangster, T. C.; Betti, R.; Craxton, R. S.; Delettrez, J. A.; Edgell, D. H.; Elasky, L. M.; Glebov, V. Yu.; Goncharov, V. N.; Harding, D. R.; Jacobs-Perkins, D.; Janezic, R.; Keck, R. L.; Knauer, J. P.; Loucks, S. J.; Lund, L. D.; Marshall, F. J.; McCrory, R. L.; McKenty, P. W.; Meyerhofer, D. D.; Radha, P. B. // Physics of Plasmas;May2007, Vol. 14 Issue 5, p058101 

    Ignition target designs for inertial confinement fusion on the National Ignition Facility (NIF) [W. J. Hogan et al., Nucl. Fusion 41, 567 (2001)] are based on a spherical ablator containing a solid, cryogenic-fuel layer of deuterium and tritium. The need for solid-fuel layers was recognized more...

  • Effect of experimentally observed hydrogenic fractionation on inertial confinement fusion ignition target performance. McKenty, P. W.; Wittman, M. D.; Harding, D. R. // Journal of Applied Physics;10/1/2006, Vol. 100 Issue 7, p073302 

    The need of cryogenic hydrogenic fuels in inertial confinement fusion (ICF) ignition targets has been long been established. Efficient implosion of such targets has mandated keeping the adiabat of the main fuel layer at low levels to ensure drive energies are kept at reasonable minima. The use...

  • The experimental plan for cryogenic layered target implosions on the National Ignition Facility-The inertial confinement approach to fusion. Edwards, M. J.; Lindl, J. D.; Spears, B. K.; Weber, S. V.; Atherton, L. J.; Bleuel, D. L.; Bradley, D. K.; Callahan, D. A.; Cerjan, C. J.; Clark, D; Collins, G. W.; Fair, J. E.; Fortner, R. J.; Glenzer, S. H.; Haan, S. W.; Hammel, B. A.; Hamza, A. V.; Hatchett, S. P.; Izumi, N.; Jacoby, B. // Physics of Plasmas;May2011, Vol. 18 Issue 5, p051003 

    Ignition requires precisely controlled, high convergence implosions to assemble a dense shell of deuterium-tritium (DT) fuel with ρR>∼1 g/cm2 surrounding a 10 keV hot spot with ρR ∼ 0.3 g/cm2. A working definition of ignition has been a yield of ∼1 MJ. At this yield the...

  • Hot-core assembly in cryogenic D2 direct-drive spherical implosions. Smalyuk, V. A.; Dumanis, S. B.; Delettrez, J. A.; Glebov, V. Yu.; Meyerhofer, D. D.; Regan, S. P.; Sangster, T. C.; Stoeckl, C. // Physics of Plasmas;Oct2006, Vol. 13 Issue 10, p104502 

    The temperature-density profiles of imploded cryogenic D2 capsules are inferred for a low-adiabat (α∼6) drive using a Monte Carlo technique described earlier [V. A. Smalyuk et al., Phys. Plasmas 12, 052706 (2005)]. The analysis has been improved by incorporating differential x-ray...

  • The magnetic recoil spectrometer for measurements of the absolute neutron spectrum at OMEGA and the NIF. Casey, D. T.; Frenje, J. A.; Gatu Johnson, M.; Séguin, F. H.; Li, C. K.; Petrasso, R. D.; Glebov, V. Yu.; Katz, J.; Magoon, J.; Meyerhofer, D. D.; Sangster, T. C.; Shoup, M.; Ulreich, J.; Ashabranner, R. C.; Bionta, R. M.; Carpenter, A. C.; Felker, B.; Khater, H. Y.; LePape, S.; MacKinnon, A. // Review of Scientific Instruments;Apr2013, Vol. 84 Issue 4, p043506 

    The neutron spectrum produced by deuterium-tritium (DT) inertial confinement fusion implosions contains a wealth of information about implosion performance including the DT yield, ion-temperature, and areal-density. The Magnetic Recoil Spectrometer (MRS) has been used at both the OMEGA laser...

  • Simultaneous usage of pinhole and penumbral apertures for imaging small scale neutron sources from inertial confinement fusion experiments. Guler, N.; Volegov, P.; Danly, C. R.; Grim, G. P.; Merrill, F. E.; Wilde, C. H. // Review of Scientific Instruments;Oct2012, Vol. 83 Issue 10, p10D316 

    Inertial confinement fusion experiments at the National Ignition Facility are designed to understand the basic principles of creating self-sustaining fusion reactions by laser driven compression of deuterium-tritium (DT) filled cryogenic plastic capsules. The neutron imaging diagnostic provides...

  • Symmetry issues in Directly Irradiated Targets. Ramis, R.; Temporal, M.; Canaud, B.; Brandon, V. // EPJ Web of Conferences;2013, Issue 59, p1 

    In direct drive Inertial Confinement Fusion (ICF), the typical laser beam to laser beam angle is around 30°. This fact makes the study of the irradiation symmetry a genuine 3D problem. In this paper we use the three dimensional version of the MULTI hydrocode to assess the symmetry of such ICF...

  • High energy x-ray imager for inertial confinement fusion at the National Ignition Facility. Tommasini, Riccardo; Koch, Jeffrey A.; Young, Bruce; Ng, Ed; Phillips, Tom; Dauffy, Lucile // Review of Scientific Instruments;Oct2006, Vol. 77 Issue 10, p10E301 

    X-ray imaging is a fundamental diagnostic tool for inertial confinement fusion (ICF) research and provides data on the size and the shape of the core in implosions. We report on the feasibility and performance analyses of an ignition x-ray imager to be used on cryogenic deuterium-tritium...

  • New tuning method of the low-mode asymmetry for ignition capsule implosions. Jianfa Gu; Zhensheng Dai; Shiyang Zou; Peng Song; Wenhua Ye; Wudi Zheng; Peijun Gu // Physics of Plasmas;Dec2015, Vol. 22 Issue 12, p1 

    In the deuterium-tritium inertial confinement fusion implosion experiments on the National Ignition Facility, the hot spot and the surrounding main fuel layer show obvious P2 asymmetries. This may be caused by the large positive P2 radiation flux asymmetry during the peak pulse resulting form...


Read the Article


Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics