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Progress in direct-drive fusion studies for the Laser Mégajoule

Published online by Cambridge University Press:  01 June 2004

B. CANAUD
Affiliation:
Département de Physique Théorique et Appliquée, Commissariat à l'Energie Atomique, Bruyères-le-Châtel, France
X. FORTIN
Affiliation:
Département de Physique Théorique et Appliquée, Commissariat à l'Energie Atomique, Bruyères-le-Châtel, France
F. GARAUDE
Affiliation:
Département de Physique Théorique et Appliquée, Commissariat à l'Energie Atomique, Bruyères-le-Châtel, France
C. MEYER
Affiliation:
Département des Lasers de Puissance, Commissariat à l'Energie Atomique, Le Barp, France
F. PHILIPPE
Affiliation:
Département de Physique Théorique et Appliquée, Commissariat à l'Energie Atomique, Bruyères-le-Châtel, France

Abstract

In the context of the French Laser Mégajoule (LMJ) fusion research program, direct drive is an alternate to indirect drive to reach ignition and thermonuclear burn. We present recent progress in the direct-drive fusion studies for LMJ. Calculations have shown that the LMJ irradiation uniformity is characterized by long wavelength asymmetries compatible with direct drive requirements. Calculations of the irradiation uniformity in the context of indirect drive beam positioning have been done. We show that non-uniformity can be minimized by repointing the beams. Unfortunately, a time analysis shows that this nonuniformity increases strongly in time above levels usually considered inconsistent for direct drive. Finally, a recent baseline target design is presented and consists of a DT ice shell surrounded by a low-density CH foam wicked with cryogenic DT. This design can potentially reach a gain of 90 with a 1-MJ on-target laser driver. Hydrodynamic stability is increased at the ablation front and the laser–target coupling efficiency achieves 85%.

Type
Research Article
Copyright
© 2004 Cambridge University Press

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References

REFERENCES

Bodner, S.E., Colombant, D.G., Gardner, J.H., Lehmberg, R.H., Obenschain, S. P., Phillips, L., Schmitt, A.J., Sethian, J.D., McCrory, R.L., Seka, W., Verdon, C.P., Knauer, J.P., Afeyan, B.B. & Powell, H.T. (1998). Direct drive laser fusion: Status and prospect. Phys. Plasmas 5, 1901.CrossRefGoogle Scholar
Bodner, S.E., Colombant, D.G., Schmitt, A.J. & Klapisch, M. (2000). High-gain direct drive target designs for laser fusion. Phys. Plasmas 7, 2298.CrossRefGoogle Scholar
Canaud, B., Dague, N., Bocher, J.L. & Fortin, X. (2002). Laser megajoule irradiation uniformity for direct drive. Phys. Plasmas 9, 4252.CrossRefGoogle Scholar
Goncharov, V.N. (1998). Self consistent stability analysis of ablation fronts in inertial confinement fusion. Ph.D. Thesis. University of Rochester, Rochester.
Lindl, J. (1995). Development of the indirect-drive approach to inertial confinement fusion and the target physics basis for ignition and gain. Phys. Plasmas 2, 3933.Google Scholar
Mark, J.W.-K. (1986). Phys. Lett. 114A, 458.
Munro, D.H. (1988). Analytic solutions for Rayleigh-Taylor growth-rates in smooth density gradients. Phys. Rev. A 38, 1433.Google Scholar
Nuckolls, J., Wood, L., Thiessen, A. & Zimmerman, G. (1972). Laser compression of matter to super-high densities: Thermonuclear applications. Nature 239, 139.Google Scholar
Pellat, R. (2000). Proc. Of 1st International Conference on Inertial Fusion Sciences and Applications (IFSA). Bordeaux, 1999. Labaune, C., Hogan, W.J. & Tanaka, K.A. (Eds.). p. 3. Paris: Elsevier.
Sacks, R.A. & Darling, D.H. (1987). Direct drive cryogenic ICF capsules employing DT wetted foam. Nucl. Fusion 27, 447.Google Scholar
Takabe, H., Mima, K., Montierth, L. & Morse, R.L. (1985). Self-consistent growth rate of Rayleigh-Taylor instability in an ablatively accelerating plasma. Phys. Fluids 28, 3676.Google Scholar