J. Phys. IV France
Volume 133, June 2006
Page(s) 371 - 378
Publié en ligne 16 juin 2006
Inertial Fusion Sciences and Applications 2005
J.-C. Gauthier, et al.
J. Phys. IV France 133 (2006) 371-378

DOI: 10.1051/jp4:2006133075

Study of electron and proton isochoric heating for fast ignition

M.H. Key1, K. Akli2, F. Beg3, M.H. Chen1, H.-K. Chung1, R.R. Freeman2, 4, M.E. Foord1, J.S. Green5, 6, P. Gu2, G. Gregori1, H. Habara7, S.P. Hatchett1, D. Hey2, J.M. Hill2, J.A. King2, R. Kodama7, J.A. Koch1, K. Lancaster5, B.F. Lasinski1, B. Langdon1, A.J. MacKinnon1, C.D. Murphy5, 6, P.A. Norreys5, N. Patel2, P. Patel1, J. Pasley3, R.A. Snavely1, R.B. Stephens8, C. Stoeckl9, M. Tabak1, W. Theobald9, K. Tanaka7, R. Town1, S.C. Wilks1, T. Yabuuchi10 and B. Zhang2

1  Lawrence Livermore National Laboratory, Livermore, CA 94550, USA
2  Department of Applied Sciences, University of California Davis, Davis, CA 95616, USA
3  University of California, San Diego, San Diego, CA 92186, USA
4  Ohio State University, Columbus, Ohio 43210, USA
5  Central Laser Facility, CCLRC, Chilton, Didcot OX11 0QX, UK
6  Blackett Laboratory, Imperial College, London SW7 2AZ, UK
7  Institute for Laser Engineering, Osaka University, Suita, Osaka, Japan
8  General Atomics, San Diego, CA 92186, USA
9  University of Rochester-Laboratory for Laser Energetics, Rochester, NY 14623, USA
10  Graduate School of Engineering, Osaka University, Suita, Osaka, Japan

Isochoric heating by electrons has been measured in the two limiting cases of small area thin foils with dominant refluxing and cone-long-wire geometry with negligible refluxing in the wire. Imaging of Cu K$\alpha $ fluorescence, crystal x-ray spectroscopy of Cu K shell emission, and XUV imaging at 68 eV and 256 eV are discussed. Laser power on target was typically 0.5 PW in 0.7 ps. Heating by focused proton beams generated at the concave inside surface of a hemi-shell and from a sub hemi-shell inside a 30$^{\circ}$ cone has been studied with the same diagnostic methods plus imaging of proton induced K$\alpha $. Conversion efficiency to protons has been measured and modeled. Conclusions from the experiments, links to theoretical understanding and relevance to fast ignition are outlined.

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