Fast ignition relevant study of the flux of high intensity laser-generated electrons via a hollow cone into a laser-imploded plasma

Journal Article · Fri Feb 15 00:00:00 EST 2008 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.2834727· OSTI ID:21103823

Key, M H; Chen, M H; Hatchett, S P; Hill, J M; King, J A; MacKinnon, A J; Patel, P; Phillips, T; Snavely, R A; Town, R ^[1]; Adam, J C; Heron, A ^[2]; Akli, K U; Stephens, R ^[3]; Borghesi, M; Romagnani, L; Zepf, M ^[4]; Evans, R G ^[5]; Freeman, R R ^[6]; Habara, H ^[7]

---

1. University of California, Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)
2. Centre de Physique Theorique (UPR14 du CNRS), Ecole Polytechnique, 91128 Palaiseau Cedex (France)
3. General Atomics, San Diego, California 92186 (United States)
4. Department of Pure and Applied Physics, Queens University of Belfast, Belfast BT7 1NN (United Kingdom)
5. Blackett Laboratory, Imperial College of Science Technology and Medicine, London SW7 2BZ (United Kingdom)
6. The Ohio State University, Columbus, Ohio 34210 (United States)
7. Rutherford Appleton Laboratory, Chilton, Oxon, OX11OQX (United Kingdom)

An integrated experiment relevant to fast ignition . A Cu-doped deuterated polymer spherical shell target with an inserted hollow Au cone is imploded by a six-beam 900-J, 1-ns laser. A 10-ps, 70-J laser pulse is focused into the cone at the time of peak compression. The flux of high-energy electrons through the imploded material is determined from the yield of Cu K{alpha} fluorescence by comparison with a Monte Carlo model. The electrons are estimated to carry about 15% of the laser energy. Collisional and Ohmic heating are modeled, and Ohmic effects are shown to be relatively unimportant. An electron spectrometer shows significantly greater reduction of the transmitted electron flux than is calculated in the model. Enhanced scattering by instability-induced magnetic fields is suggested. An extension of this fluor-based technique to measurement of coupling efficiency to the ignition hot spot in future larger-scale fast ignition experiments is outlined.

• OSTI ID: 21103823
• Journal Information: Physics of Plasmas, Vol. 15, Issue 2; Other Information: DOI: 10.1063/1.2834727; (c) 2008 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 1070-664X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
COMPARATIVE EVALUATIONS
COPPER
DOPED MATERIALS
ELECTRON SPECTROMETERS
ELECTRONS
FLUORESCENCE
GOLD
LASERS
MAGNETIC FIELDS
MONTE CARLO METHOD
PLASMA
PLASMA DIAGNOSTICS
PLASMA HEATING
SPHERICAL CONFIGURATION