Ideal laser-beam propagation through high-temperature ignition Hohlraum plasmas.
We demonstrate that a blue (3omega, 351 nm) laser beam with an intensity of 2 x 10(15) W cm(-2) propagates nearly within the original beam cone through a millimeter scale, T(e)=3.5 keV high density (n(e)=5 x 10(20) cm(-3)) plasma. The beam produced less than 1% total backscatter at these high temperatures and densities; the resulting transmission is greater than 90%. Scaling of the electron temperature in the plasma shows that the plasma becomes transparent for uniform electron temperatures above 3 keV. These results are consistent with linear theory thresholds for both filamentation and backscatter instabilities inferred from detailed hydrodynamic simulations. This provides a strong justification for current inertial confinement fusion designs to remain below these thresholds.
Froula
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DH
Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, CA 94551, USA. froula1@llnl.gov
Divol
L
L
Meezan
N B
NB
Dixit
S
S
Moody
J D
JD
Neumayer
P
P
Pollock
B B
BB
Ross
J S
JS
Glenzer
S H
SH