Proton Radiography of Spontaneously-Generated Electromagnetic Fields in Laser-Produced High-Energy-Density Plasmas

sunglowcitrineΠολεοδομικά Έργα

15 Νοε 2013 (πριν από 3 χρόνια και 11 μήνες)

100 εμφανίσεις

Invited talk for HEDLP 2010



Proton Radiography of Spontaneously-Generated Electromagnetic
Fields in Laser-Produced High-Energy-Density Plasmas

R. D. Petrasso
1
, C. K. Li
1
, F. H. Séguin
1
, J. A. Frenje
1
, P. A. Amendt
2
, O. L. Landen
2
, R.
P. J. Town
2
, R. Bett
3
, D. D. Meyerhofer
3
, and J. D. Kilkenny
4



1
Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge,
MA 02139, USA.

2
Lawrence Livermore National Laboratory, Livermore, CA 94550, USA.
3
Laboratory for Laser Energetics, University of Rochester, Rochester, NY 14623, USA.
4
General Atomics, San Diego, CA 92186, USA


Time-gated, monoenergetic-proton radiography provides unique measurements of
spontaneous electric (E) and magnetic (B) fields produced in laser-foil interactions,
during implosions of inertial-confinement-fusion capsules, and in laser-irradiated
hohlraums. These experiments resulted in the first observations of several new and
important features. For the case of laser-foil interactions, the generation, decay dynamics,
topology changes, and instabilities of megagauss B fields were imaged. For the case of
directly-driven implosions, radial E fields inside an imploding capsule and, surrounding
the capsule, many radial filaments with complex electromagnetic field striations were
observed. For the case of laser-irradiated gold hohlraums and indirectly-driven
implosions, three types of spontaneous E fields, which differ by two orders of magnitude
with the largest approaching the Bohr field strength were observed. Also imaged and
radiographed were plasma flows, supersonic jet formation, and self-generated B fields.
The physics behind and implications of such fields will be discussed.