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Modeling turbulent mixing in inertial confinement fusion implosions

Published online by Cambridge University Press:  03 March 2004

YAIR SREBRO ,
DORON KUSHNIR ,
YONI ELBAZ  and
DOV SHVARTS
YAIR SREBRO
Affiliation:
Department of Physics, Ben-Gurion University, Beer-Sheva, Israel Department of Physics, Nuclear Research Center–Negev, Israel
DORON KUSHNIR
Affiliation:
Department of Physics, Nuclear Research Center–Negev, Israel Department of Physics, Hebrew University, Jerusalem, Israel
YONI ELBAZ
Affiliation:
Department of Physics, Ben-Gurion University, Beer-Sheva, Israel Department of Physics, Nuclear Research Center–Negev, Israel
DOV SHVARTS
Affiliation:
Department of Physics, Ben-Gurion University, Beer-Sheva, Israel Department of Physics, Nuclear Research Center–Negev, Israel Department of Mechanical Engineering, Ben-Gurion University, Beer-Sheva, Israel
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Abstract

Recent direct drive implosion experiments, performed on the OMEGA laser, have been analyzed by comparing full two-dimensional (2D) and one-dimensional (1D) numerical simulations. The 2D simulations result in a fusion yield higher than experimental results. A simple full-mixing model, leaving only the clean region, overestimates yield degradation. Fully turbulent mixing is expected to develop in most of the mixing region; however regions slightly beyond the radius of the most penetrating spike are expected to remain clean and to contribute to fusion yield. One can correct the mixing model by redefining the clean region. Accounting for this unmixed region results in improved agreement with experimental results. Differences in central pressure, density, temperature, and fusion rate in implosions dominated by low mode number perturbations imply that mix effects might not be limited to the mix region, and that 2D simulations are necessary to describe the large scale flow affecting the central region. The same analysis has been undertaken for implosions with different convergence ratios, but with similar initial perturbation spectra. These implosions should be compared to implosions dominated by high mode number perturbations, which might be described by models based on 1D simulations.

Keywords

Direct numerical simulationsHydrodynamic instabilitiesInertial confinement fusionSecondary instabilitiesTurbulent mixing
Type
Research Article
Information
Laser and Particle Beams , Volume 21 , Issue 3 , July 2003 , pp. 355 - 361
Copyright
© 2003 Cambridge University Press

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References

REFERENCES

Brown, G.L., & Roshko, A.J. (1974). On the density effects and large structure in turbulent mixing layers. J. Fluid Mech. 64, 775–816.CrossRefGoogle Scholar
Gauthier, S., & Bonnet, M. (1990). A k-epsilon model for turbulent mixing in shock-tube flows induced by Rayleigh–Taylor instability. Phys. Fluids A 2, 1685–1694.CrossRefGoogle Scholar
Goncharov, V.N., McKenty, P., Skupsky, S., Betti, R., McCrory, R.L., & Cherfils-Clerouin, C. (2000). Modeling hydrodynamic instabilities in inertial confinement fusion targets. Phys. Plasmas 7, 5118–5139.CrossRefGoogle Scholar
Kishony, R., & Shvarts, D. (2001). Ignition condition and gain prediction for perturbed inertial confinement fusion targets. Phys. Plasmas 8, 4925–4936.CrossRefGoogle Scholar
Levedahl, W.K., & Lindl, J.D. (1997). Energy scaling of inertial confinement fusion targets for ignition and high gain. Nucl. Fusion 37, 165–173.CrossRefGoogle Scholar
Lindl, J.D. (1995). Development of the indirect-drive approach to inertial confinement fusion and the target physics basis for ignition and gain. Phys. Plasmas 2, 3933–4024.CrossRefGoogle Scholar
Marshall, F.J., Delettrez, J.A., Epstein, R., Glebov, V.Yu., Harding, D.R., McKenty, P.W., Meyerhofer, D.D., Radha, P.B., Seka, W., Skupsky, S., Smalyuk, V.A., Soures, J.M., Stoeckl, C., Town, R.P.J., Yaakobi, B., Li, C.K., Seguin, F.H., Hicks, D.G., & Petrasso, R.D. (2000). Direct-drive high-convergence-ratio implosion studies on the OMEGA laser system. Phys. Plasmas 7, 2108–2113.CrossRefGoogle Scholar
Meyerhofer, D.D., Delettrez, J.A., Epstein, R., Glebov, V.Yu., Goncharov, V.N., Keck, R.L., McCrory, R.L., McKenty, P.W., Marshall, F.J., Radha, P.B., Reagan, S.P., Roberts, S., Seka, W., Skupsky, S., Smalyuk, V.A., Sorce, C., Stoeckl, C., Soures, J.M., Town, R.P.J., Yaakobi, B., Zuegel, J.D., Frenje, J., Li, C.K., Petrasso, R.D., Seguin, F.H., Fletcher, K., Padalino, S., Freeman, C., Izumi, N., Lerche, R., Phillips, T.W., & Sangster, T.C. (2001). Core performance and mix in direct-drive spherical implosions with high uniformity. Phys. Plasmas 8, 2251–2256.CrossRefGoogle Scholar
Radha, P.B., Delettrez, J., Epstein, R., Glebov, V.Yu., Keck, R., McCrory, R.L., McKenty, P., Meyerhofer, D.D., Marshall, F., Reagan, S.P., Roberts, S., Sangster, T.C., Seka, W., Skupsky, S., Smalyuk, V., Sorce, C., Stoeckl, C., Soures, J., Town, R.P.J., Yaakobi, B., Frenje, J., Li, C.K., Petrasso, R., Seguin, F., Fletcher, K., Padalino, S., Freeman, C., Izumi, N., Lerche, R., & Phillips, T.W. (2002). Inference of mix in direct-drive implosions on OMEGA. Phys. Plasmas 9, 2208–2213.CrossRefGoogle Scholar
Sharp, D.H. (1984). An overview of Rayleigh–Taylor instability. Physica D 12, 3.CrossRefGoogle Scholar
Skupsky, S., Short, R.W., Kessler, T., Craxton, R.S., Letzring, S., & Soures, J.M. (1989). Improved laser-beam uniformity using the angular dispersion of frequency-modulated light. J. Appl. Phys. 66, 3456–3462.CrossRefGoogle Scholar
Youngs, D.L. (1984). Numerical simulation of turbulent mixing by Rayleigh–Taylor instability. Physica D 12, 32–44.Google Scholar
Youngs, D.L. (1989). Modelling turbulent mixing by Rayleigh–Taylor instability. Physica D 37, 270–287.CrossRefGoogle Scholar
Youngs, D.L. (1994). Numerical simulation of mixing by Rayleigh–Taylor and Richtmyer–Meshkov instabilities. Laser Part. Beams 12, 725–750.CrossRefGoogle Scholar