1. ENERGY FLOW IN DENSE OFF-EQUILIBRIUM PLASMAS Submitted by Seth Putterman; January 7, 2013
We have taken a movie of the transport of energy across a dense plasma!
The goal is to generate and validate the kinetic theory of a dense plasma. 1 2 3 4 5 6 7 8
Frames from a movie of the propagation of an energy pulse across a dense plasma.
Free charge density = 1021/cc ; diameter = 100.µm; time between frames = 10ns.
Prof. K. Weninger; Dr B. Kappus

2. Experiment 2: Calorimetry of a Dense Plasma : shows that the
Ionization potential is reduced by 85% !
Apparatus [rt] for generating
A dense plasma in a spherical
imploding gas bubble
(40,000. implosions/s). We use
xenon surrounded by sulfuric acid
because of its low vapor pressure.
Photo of bubble at max radius
[red-left] and light emission [blue]
from the dense plasma.
Mie scattering over one
Implosion cycle [left]
with blowup near
minimum radius [rt].
Energy balance based upon a precision measurement of the radius of an imploding bubble
in sulfuric acid yields the energy residing in the dense plasma formed inside the collapsed bubble.
A lower limit on the plasma density is determined by its 8,000K blackbody spectrum which places
a lower bound of 1021/cc on the free charge. Note that the minimum radius matches the
Blackbody’s spectral radius.
Bataller-Kappus

3. Experiment 3: Diagram of Apparatus to Measure Response of Dense Plasma to Different Wavelengths of Light. The goal is to determine the collision time/kinetics of a dense plasma.
Xenon in Water
Bataller-Kappus

4. Measurement of both Mie scattering
[red] and light emission [black]
from a xenon gas bubble that
implodes to about a one micron
diameter where it forms a
dense plasma – at time ‘0’ on the ‘x’
Axis.
Light emission is due to two effects
Thermal process in the
dense plasma [lower band]
Absorption and emission of a 3ns
YAG pulse that hits the bubble
during the 1ns lifetime of
the plasma.
Our measurements find that 532nm
always interacts with the plasma
whereas for 1064nm there is a
threshold. See gap at PMT
ordinate 101.
While one is tempted to ascribe this
behavior to the plasma frequency our
theory suggests that the short
collision time is in fact the key
consideration.

5. {For neon we have a achieved a density of 1022/cc}
Experiment 4: We have created a dense hydrogen plasma with a density > 1021/cc
{For neon we have a achieved a density of 1022/cc}
We have used a shake tube vibrating at 40Hz for this experiment.
40Hz apparatus with Xe
The density of the plasma is diagnosed by its size and opacity as indicated by its blackbody
Spectrum.
Kappus- Weninger