Author Affiliations
1Nuclear Fusion Institute, Polytechnic University of Madrid, Madrid, Spain2Applied Physics Division, Soreq NRC, Yavne, Israel3Hebrew University of Jerusalem, Jerusalem, Israelshow less
Fig. 1. The fluid flow velocities
and
as seen in the shock wave singularity frame of reference
and the shock wave velocity
and the particle flow velocities
and
as seen in the laboratory frame of reference.
Fig. 2. (a) The capacitor model for laser irradiances
where the ponderomotive force dominates the interaction. (b) The parameters that define our capacitor model:
and
are the electron and ion densities accordingly,
is the electric field,
is the distance between the positive and negative DL charges. The DL is geometrically followed by a neutral plasma where the electric field decays within a skin depth
and a shock wave is created. (c) The shock wave description in the piston model.
Fig. 3. The compression
as a function of the shock wave dimensionless pressure
. The numerical values are obtained for
.
Fig. 4. The dimensionless shock wave pressure
versus the dimensionless laser irradiance
in the range 10
. For a better understanding of this graph the inserted table shows numerical values in the range
.
Fig. 5. The dimensionless shock wave velocity
and the particle velocity
in the laboratory frame of reference versus the dimensionless laser irradiance
in the range
. For a better understanding of this graph the inserted tables show numerical values in the range
.
Fig. 6. The speed of sound
is given in units of the speed of light
in (a) and the ratio of the shock velocity to the rarefaction velocity,
is shown in (b) as function of the dimensionless laser irradiance
in the range
. The inserted tables show numerical values in the range
.
Fig. 7. The FI scheme suggested in this paper. As a numerical example an initial pellet with radius
and DT fuel of density
with thickness
(i.e., an aspect ratio of 10) is compressed to a density of
by nanosecond lasers with a radius of
. The picosecond fast igniter laser with a
beam diameter creates a shock wave pulse with a thickness of
and can be considered a 1D shock wave to a reasonable approximation.
$\Pi _{\mathrm{L}}$ | $\rho _{0}$ | $I_{\mathrm{L}}$ | $\kappa $ | ($u_{\mathrm{s}}-u_{\mathrm{p}})/c$ | $\tau _{\mathrm{L}}$ | $l_{\mathrm{s}}$ | $S$ | $W_{\mathrm{L}}$ | $P_{\mathrm{L}}$ |
---|
| $(\mathrm{g\ cm}^{-3})$ | $(\mathrm{W\ cm}^{-2})$ | | | $(\mathrm{ps})$ | $(\mu \mathrm{m})$ | $(\mathrm{cm}^{2})$ | $(\mathrm{kJ})$ | (PW) |
---|
| | | 4 | | 1.6 | 0.72 | | 30 | 19 | | | | 4 | | 0.5 | 0.75 | | 60 | 120 | | | | 4 | | 0.2 | 0.78 | | 260 | 1300 |
|
Table 1. The laser is defined by its irradiance
, pulse duration
, energy W
and power P
. This laser creates a shock wave with a compression
in a pre-compressed target with an initial density
. The shock wave thickness
, where
and
are the shock wave velocity and the particle velocity respectively) and its cross section are
and
, respectively, satisfying
in order to have a 1D shock wave.