CP620, Shock Compression of Condensed Matter - 2001
edited by M. D. Furnish, N. N. Thadhani, and Y. Horie
2002 American Institute of Physics 0-7354-0068-7
For special copyright notice, see page 82.
MEASUREMENTS OF THE EQUATION OF STATE OF LEAD UNDER
VARYING CONDITIONS BY MULTIPLE METHODS.
SJX Rothman, A.M. Evans, P. Graham, K.W. Parker, J. Palmer.
AWEAldermaston, Reading, RG74PR, U.K.
T. Jalinaud.
CEA Bruyeres-le-Chatel, BP No. 12, 91680, Bruyeres-le-Chatel, France.
J-P. Davis, J. Asay, M. Knudson, C. Hall.
SNL, PO Box 5800, MS 1181, Albuquerque, NM87185 , USA..
Abstract. For the past few years AWE has been pursuing a programme of principal Hugoniot EOS
measurements on metals and plastics at multi-Mbar pressures. Recently we have decided to concentrate
on measurements on lead by a number of different techniques to cover as much of the EOS parameter
space as possible. Using the HELEN laser we have made more Hugoniot measurements from -SOOkbar
to -lOMbar. We have also performed isentropic compression experiments up to -IMbar using the
Sandia National Laboratory's Z machine. These were on single-crystal and bulk lead and a leadantimony alloy. These complementary experiments allow us to compare single-crystal, bulk and alloyed
materials, to compare Hugoniots and isentropes at IMbar and to compare laser-driven experiments with
existing gas-gun and explosively driven data at low pressures. This presentation will describe these
experiments and the results, with emphasis on the ways in which they are complemetary: how one
measurement can verify another, how techniques and diagnostics carry-over, and the ways in which one
method can provide data not possible from another.
We have recently decided to concentrate on one
material - lead - and to measure its EOS over as
wide a range of conditions as possible.
Potential experiments included isentropic
compression, adiabatic release and shocking of
porous material.
Our plan is to continue with Principal Hugoniot
measurements, extending the experiment down to
pressures of <IMbar. Low pressure measurements
use essentially the same techniques as high-pressure
ones, with some details in laser target dimensions,
the main difference being use of an active shockbreakout diagnostic, rather than optical emission
measurements, as shock temperature falls below a
detection threshold. These measurements may also
INTRODUCTION
AWE has been conducting a programme of high
pressure (<20Mbar) Principal Hugoniot experiments
for several years using shocks generated by laserdriven hohlraums (1, 2). Data from the Principal
Hugoniot is important as it often provides the
reference curve for a Mie-Gruneisen form of EOS,
however it is only a single locus in the EOS plane
and therefore does not cover the entire range over
which data may be needed. Off-Hugoniot data is
obviously necessary to validate other assumptions of
the models.
79
be compared
- explosively-driven
difference with
beingconventional
use of an active
shock-breakout
and diagnostic,
gas-gun - datarather
to validate
laser technique.
than theoptical
emission
Recently
the Zas accelerator
at Sandia
National
measurements,
shock temperature
falls below
a
Laboratories
has been
used for isentropic
detection threshold.
These measurements
may also
being
of anatactive
shock-breakout
be difference
compared
with use
conventional
– explosivelycompression
experiments
(ICE)
a few
lOOkbar (3).
rather
than
optical
and gas-gun
data
to lead,
validate
the emission
laser
We driven
havediagnostic,
performed
ICE– on
bulk
single-crystal
measurements,
as
shock
temperature
falls
leadtechnique.
and lead-antimony alloy (3% by weightbelow
Sb). a
detection the
threshold.
These measurements
may also
Recently
Z
accelerator
at
Sandia
National
Data for these materials are still to be analysed.
be compared
with
conventional
explosivelyLaboratories
has
used adiabatic
for – isentropic
Future
plans
are
tobeen
measure
release
driven
and
gas-gun
–
data
to
validate
the laser
experiments
(ICE)
atproduced
a few 100kbar
fromcompression
an
SMbar
shocked
state
by a
(3). technique.
We have performed
ICE
lead,Hugoniot
singlemagnetically-driven
ZZ accelerator
flyer,on bulk
andSandia
Recently
the
at
National
crystal leadon and
lead-antimony
alloy (3% by
measurements
porous
lead.
Laboratories
hasthese
been
used are
forstillisentropic
weight
Sb). Data for
materials
to be
Thiscompression
article describes
the (ICE)
Principal
Hugoniot
experiments
at
a few
100kbar
analysed.
experiments
andhave
isentropic
compression
experiments
(3). We
performed
ICE on bulk
lead, singleFuture plans are to measure adiabatic release
and from
outlines
release
porous
lead
experiments.
crystalthelead
andand
lead-antimony
alloy (3% by
an 8Mbar shocked state produced by a
0.53jJLin, Ins gaussian
500J Laser pulse.
mm x 1mm hohlraum.
Figure1.1.Schematic
Schematic of
of Principal
Principal Hugoniot
Figure
Hugoniotexperiment.
experiment.AA
laser-heatedhohlraum
hohlraum drives
drives aa shock
laser-heated
shock into
intoaastepped
steppedtarget
targetfoil
foil
overaahole
holeininthe
thehohlraum
hohlraum end
over
end wall.
wall. Shock
Shockbreakout
breakouttimes
times
arerecorded
recordedby
byoptical
optical streak
streak cameras.
are
cameras.
Figure 1. Schematic of Principal Hugoniot experiment. A
thicknesses
and
a longer
laser
pulse
allow
forfoil
laser-heated
hohlraum
drives
a shock
into
stepped
target
reflectivity
at
shock
breakout.
Thea to
impedance-match
overshock
a hole in the
hohlraum end
wall. Shock
breakout times
lower
velocities.
Shock
breakout
was
analysis
is yet
to be streak
done.cameras.
are recorded
by optical
detected
by the
change in
reflectivity of the
surface using a ruby probe laser and streak
thicknesses and a longer laser pulse to allow for
cameras.
lower shock
velocities. Shock
breakout was
Z ISENTROPIC
COMPRESSION
An initial
streak result is
shown in Fig. 2.
detected by EXPERIMENTS
the change in reflectivity
of the
(ICE).
Reflectivity actually increases at shock
breakout –
surface using a ruby probe laser and streak
which
is probably a combination of change in
cameras.
The
Z pulsed-power
machine has recently
been
optical
and surface
Anproperties
initial streak
result isroughness
shown ineffects,
Fig. 2.
to
generate
magnetic
pressure
pulses
allowing
asused
streaks
of
machined
wedge
targets
show
a
clear
Reflectivity actually increases at shock breakout –
quasi-isentropic
compression
thin
samples
cut-off
shockofbreakout.
Thein (3) which inis reflectivity
probably
a at
combination
of change
impedance-match
analysis
is
yet
to
be
done.
Fig.
3.
Free-surface
velocities
are
recorded
by fibreoptical properties and surface roughness effects,
optic
VISAR
probes.
Assuming
free-surface
as streaks of machined wedge targets show a clear
velocity
particle The
velocity,
cut-off is
in approximately
reflectivity at twice
shock the
breakout.
Z ISENTROPIC
COMPRESSION
Up,
then
the time
difference
different
impedance-match
analysis
is yet to bebetween
done.
thickness EXPERIMENTS
samples reaching(ICE).
the same up gives the
weight Sb). Data for these materials are still to be
magnetically-driven Z flyer, and Hugoniot
analysed.
measurements on porous lead.
Future plans are to measure
adiabatic release
PRINCIPAL
This articleHUGONIOT
describes theEXPERIMENTS
Principal Hugoniot
from an 8Mbar shocked state produced by a
experiments
and
isentropic
compression
magnetically-driven
Z flyer, and
Hugoniot
These
have been
described
inrelease
Ref.s 1and
andporous
2. The
experiments
and
outlines
the
measurements on porous lead.
HELEN
1TW
laser
at
AWE
is
used
to
heat
a
lead experiments.
This article describes the Principal Hugoniot
hohlraum
to drive a and
shock isentropic
into a stepped
target:
experiments
compression
shock velocities
are
measured
from
step
transit
experiments and outlines the release and times
porous
and an
EOSexperiments.
pointHUGONIOT
is calculatedEXPERIMENTS
by the impedance
PRINCIPAL
lead
match method (4), using aluminium as a standard. A
These
have been
described
in Ref.s 1 and 2.
schematic
is shown
in Fig.
1.
The HELEN
1TW laser
at AWEyielded
is used to
heatdata
a
Our
experiments
on copper
-30
PRINCIPAL
HUGONIOT
EXPERIMENTS
hohlraum
to
drive
a
shock
into
a
stepped
target:
points in the 10-20Mbar range, where only a few
shock velocities
measured
from
stepand
transit
Thesepoints
havearebeen
described
in Ref.s
1 and
nuclear-driven
existed
previously,
have2.
times
an EOS
point
isshock
calculated
the a
The
HELEN
1TW
laser in
at
AWE
is usedby
to heat
reached
anand
accuracy
of 1.2%
velocity.
impedance
match
method
(4),
as
hohlraum
to drive
aon
shock
into
stepped target:
Our
most recent
shots
leadusing
haveaaluminium
achieved
1%
a
standard.
A
schematic
is
shown
in
Fig.
1.
shock
velocities
are
measured
from
step
transit
accuracy in velocity, 3-4% in calculated pressure.
Our
on copper
~30 by
data
timesexperiments
and
EOS
point measurements
isyielded
calculated
the
Furthermore,
two an
independent
have
points
in the 10-20Mbar
range,
a few as
impedance
match method
(4),where
using only
aluminium
been made on some shots with the calculated
nuclear-driven
points
existed
previously,
and
a standard. A
schematic
is shown
in Fig.
1. have
pressures and particle velocities mostly agreeing
reachedOur
an accuracy
of 1.2%
in shock
velocity.
experiments
on copper
yielded
~30 data
within Our
the
estimated
errors,
e.g, lead
shot where
0536 gave
=
points
in the
10-20Mbar
only aPfew
most
recent
shots onrange,
have1 achieved
8.25±0.35
Mbar, in
up points
=velocity,
6.41±0.27
(linns'
and
=
existed
previously,
andPhave
1% nuclear-driven
accuracy
3-4%
in
calculated
1
8.55±0.41
Mbar,
uaccuracy
^imns"
.independent
reached
anFurthermore,
of 1.2%two
in shock
velocity.
p = 6.61±0.32
pressure.
Low-pressure
experiments
used
a achieved
larger
Our most
recent
shots
on lead
have
measurements
have
been
made
on some
shots
1%
accuracy
in
velocity,
3-4%
in
calculated
hohlraum
for
lower
drive
and
different
target
with the calculated pressures and particle
pressure.
twotheto estimated
independent
thicknesses
and
a Furthermore,
longer
laserwithin
pulse
allow for
velocities
mostly
agreeing
measurements
have
made on
shots
lower
shock
Shock
wassome
detected
errors,
e.g,velocities.
shot 0536
gavebeen
P breakout
= 8.25±0.35
Mbar,
up
-1
with
calculated
pressures
and using
particle
by the
changethein
reflectivity
the surface
µmns
= 6.41±0.27
and P =of
8.55±0.41
Mbar,
up = a
velocities
mostly
agreeing
within the estimated
-1
ruby6.61±0.32
probe
laser
and
cameras.
µmns
. streak
errors,
e.g,
shot
0536
gave
P
= used
8.25±0.35
Mbar,
An Low-pressure
initial streak experiments
result
is shown
ina Fig.
larger2.up
-1
µmns
=
6.41±0.27
and
P
=
8.55±0.41
Mbar,
up-=
Reflectivity
increases
at shock
breakout
hohlraum actually
for lower
drive and
different
target
-1
.
which is6.61±0.32
probablyµmns
a combination
of change in optical
experiments
usedas astreaks
larger
properties Low-pressure
and surface roughness
effects,
hohlraum for lower drive and different target
of machined wedge targets show a clear cut-off in
sound speed, CL , as a function of up.
The Z
pulsed-power
machine has recently
Z CL
ISENTROPIC
COMPRESSION
= (t2-ti) / (x2-xO
been
usedx is
to sample
generatethickness
magneticand
pressure
EXPERIMENTS
(ICE).
Where
t is thepulses
time for the
allowing
of thin
surface toquasi-isentropic
reach velocity ucompression
.
p
samples
– pulsed-power
Fig. 3. Free-surface
areV, and
The(3)Zpressure,
machinevelocities
has recently
Then
P, specific
volume,
recorded
by
fibre-optic
VISAR
probes.
Assuming
been
used
to
generate
magnetic
pressure
pulses
internal energy, E, may be found from:
free-surface
velocity is approximately
allowing quasi-isentropic
compressiontwice
of the
thin
dP = I/VQ. CL. dup
particle
up, 3.then
the timevelocities
difference
samplesvelocity,
(3) – Fig.
Free-surface
are
dV = V 0 .du p /c L
recorded
by fibre-optic
VISAR
probes.
Assuming
between
different
thickness
samples
reaching
the
dE =theP sound
. dV is speed,
free-surface
approximately
twice the
same
up gives velocity
cL , as a function
...allowing
isentrope
to be calculated
particle
velocity,an uentire
p, then the time difference
from
eachdifferent
shot. Vthickness
temperature
and the
pressure
0 is room samples
between
reaching
volume.
same up gives the sound speed, cL , as a function
Figure 2. Streak of reflectivity from an Al and Pb step target.
Time runs left-right and space up-down. Reflectivity initially
increases when the shock breaks out at each surface.
Figure 2. Streak of reflectivity from an Al and Pb step target.
Figure
2. Streak
of reflectivity
from an Al
and Pb step
target.
Time runs
left-right
and space up-down.
Reflectivity
initially
Time
runs left-right
space
up-down.
Reflectivity
increases
when the and
shock
breaks
out at each
surface. initially
increases when the shock breaks out at each surface.
80
Copper panel.
Sample
Window.
Window.
Velocity
Velocity
interferometer.
locity
interferometer.
interferometer.
Magnetic field.
Magnetic
Magneticfield.
field.
5.0
5.0
5.0
Sample
Anode
Anode
Current
pulse
- ~20MA,
~60kV,
~100ns.
Current
pulse
- ~20MA,
~60kV,
~100ns.
Current pulse - -20MA, ~60kV, ~100ns.
4.5
— North Top 03
3.5
3.0
35
Ig3.0
'
3.0
2.5
2.5
$2.5
3.5
2.0
1.5
1.0
Center MP1
North Top 03 — North
North Center MP1
North Center 04
North Center MP1
— North Center 04
North Bottom MP2
North Center 04
— North Bottom MP2
North Bottom MP2 East Top 04
— East Top 04
East Top 04
East Center MP1
— East Center MP1
East Center MP1 East Center 03
— East Center 03
East Center 03
East Bottom MP2
—
East Bottom MP2
East Bottom MP2 East
Bottom 03
East Bottom 03
East Bottom 03 — South
Top 03
South Top 03 — South Top 03
South Center MP1
—
South
Center MP1
South Center MP1
South Center 04
South Center 04— South Center 04
South Bottom MP2
South Bottom MP2
— South Bottom MP2
South Bottom 03
South Bottom 03— South Bottom 03
West Top 04
West Top 04
— WestTop04
West Top 03
West Top 03
— West Top 03
West Center MP1 West Center MP1
— West Center MP1
West Bottom MP2 West Bottom MP2
— West Bottom MP2
West Bottom 04
West Bottom 04
4.0
•f 4.0
2.0
1.5
1.0
0.5
0.5
Figure
3.
Schematic
ofmagnetically-driven
Z magnetically-driven
Figure
Schematic
of Z
Z
magnetically-driven
ICE
Figure
3.3.Schematic
of
ICEICE
experiment.
current
pulse
and
the
field
it it it
experiment.
A
current
pulse
the
magnetic
experiment.
AAcurrent
pulse
andand
the magnetic
magnetic
fieldfield
generates
produce
magnetic
pressure
pulse
inina acopper
generates
produce
a magnetic
pressure
pulse
incopper
a copper
generates
produce
aamagnetic
pressure
pulse
panel
which
transmits
stress
wave
into
aasample.
panel
which
transmits
a stress
wave
a sample.
panel
which
transmits
aa stress
wave
intointo
sample.
ofofAn
upu.p. alternative analysis can be done by the
cLc= =
(t2(t
-t1-t
) / (x2-x1) )
L integration"
2 1 ) / (x2 -x
1
"backwards
method
of Hayes (5),
Where
x
is
sample
thickness
andand
t is tthe
timetime
for for
Where EOS
x is sample
thickness
is the
varying
parameters
until
calculation
and
the surface to reach velocity up.
the surface data
to reach
velocity
up.
experimental
match
for
multiple
thicknesses.
Then pressure, P, specific volume, V, and
Then
pressure,
P, specific
volume,
and
Two
shots
have
been
fired from:
using
AWE V,
targets
internal
energy,
E, may
be found
internal
energy,
E,
may
be
found
from:
(Z753
and
Z770).
For
Z753
a
four
panel
dP = 1/v0 . cL . dup
dP= =was
. cL . du
0used
p
configuration
with
each panel having
dV
V1/v
0 . dup / cL
dV
=
V
.
dup / cL of bulk lead, single0 samples
identical dE
thickness
= P . dV
=an
P entire
. lead-antimony
dV isentrope to alloy.
crystal
leaddE and
The four
…allowing
be calculated
isentrope
be calculated
from …allowing
each were
shot. an
V0entire
is300,
room
and
thicknesses
200,
400temperature
andto 600
microns.
from
each
shot.comparison
V0 is room
temperature
and
pressure
volume.
This
allowed
direct
of the
materials even
pressure
volume.
Anfull
alternative
analysis
can repeated
be done the
by 300
the and
before
data analysis.
Z770
“backwards
integration”
method
ofbe400jim
Hayes
An
alternative
done (5),
bybulk
the
400um
panels
and hadanalysis
200,
300canand
of
varying
EOS
parameters
until
calculation
and (5),
“backwards
integration”
method
of
lead and alloy respectively on the last twoHayes
panels.
experimental
data parameters
match for multiple
thicknesses.
varying
EOS
calculation
and
Fig. 4 shows
the
measured until
free-surface
velocities
Two shots have
been
fired
using
AWE
targets
experimental
data
match
for
multiple
thicknesses.
from
shotand
Z753.
No analysis
has yet
been done,
and
(Z753Two
Z770).
For
a four
panel
shots
have
been Z753
fired
using
AWE
targets
there
are
possible
absolute
timing
errors,
but
there
configuration
used For
with each
panel
havingpanel
(Z753
and was
Z770).
Z753
athicknesses
four
are
clear differences
betweenofthe
same
identical
thickness samples
bulk
lead,
single- of
configuration
was used with each panel having
the
three lead
different
crystal
and materials.
lead-antimony alloy. The four
identical
thickness
samples of bulk lead, singlethicknesses were 200, 300, 400 and 600 microns.
crystal
lead direct
and lead-antimony
alloy.
The four
This
allowed
comparison of the
materials
thicknesses
were
200,
300,
400
and
600
even
before full data
analysis. Z770
repeatedmicrons.
the
ADIABATIC
RELEASE
EXPERIMENT
This
allowed
direct
comparison
of
300 and 400µm panels and had 200, the
300materials
and
1 repeated the
even
Z770
400µm
of bulkfull
leaddata
and analysis.
alloya respectively
on the
This before
experiment
will
use
lOkms"
magnetically300
and
400µm
panels
and
had
300shock
and
last two
panels. Z flyer to drive an200,
driven
aluminium
SMbar
400µm
of
bulk
lead
and
alloy
respectively
on
thea
Fig.
4
shows
the
measured
free-surface
into a lead baseplate. On the ISOjum baseplate are
velocities
from shot Z753. No analysis has yet
last
two
panels.
250jim lead step and samples for the lead to release
been Fig.
done, 4andshows
there arethe
possible
absolute
timing
measured
3 free-surface
into:
600|J,m
Al, 600jim
of 0.2gcm"between
SiO the
aerogel
errors,
but there
clearZ753.
velocities
fromareshot
No analysis2 has
yet
3 differences
and
lOOOjum
of
0.1
gem"
SiO
aerogel,
calculated
to
2
same
the three
different
materials.timing
beenthicknesses
done, andofthere
are possible
absolute
4.0
North Top 03
4.5
4.5
free-surface velocity (km/s)
Short-circuit
Short-circuittotocathode.
cathode.
Copper panel.
free-surface velocity (km/s)
Short-circuit to cathode.
— West Bottom 04
0.0
0.0
0.0
0.2
0.0
0.4
0.2
0.6
0.4
0.4
0.8
0.6
0.6
1.00.8
0.8
1.2 1.0
1.2
time (µs) time (µs)
time (MS)
FigureFigure
4. Plot 4.
of Plot
free-surface
velocitiesvelocities
measuredmeasured
by
of free-surface
free-surface
by
Figure
4. Plot
of
velocitiesofmeasured
by
VISARVISAR
for shotfor
Z753.
Data
forData
3 thicknesses
3
shot
Z753.
for
3
thicknesses
of 33
VISAR
for
shot
Z753.
Data
for
3
thicknesses
of
materials show differences between the materials.
materials
differences between
between the materials.
materials show differences
experiments), the three release states and a freesurface velocity
measurement
using a gap and
ADIABATIC
RELEASE
EXPERIMENT
ADIABATIC
EXPERIMENT
window
above theRELEASE
lead give five
points on a release
adiabat.
This experiment will use a 20kms-1
-1
This experiment
will
magnetically-driven
aluminium Z
flyer use
to drivea an 20kms
magnetically-driven
aluminium
to drive an
8Mbar
shock into a lead baseplate.
On Ztheflyer
150µm
8Mbar
into lead
a lead
On the
POROUS
LEAD
HUGONIOT
baseplate
areshock
a 250µm
stepbaseplate.
and
samples
for 150µm
baseplate
are ainto:
250µm
lead Al,
step600µm
and samples
for
the lead
to release
600µm
of
-3
provisionally
be ofan0.1gcm
impedance-match
the-3 This
lead
to
release
600µm
Al,
600µm
of
0.2gcm
SiO2 will
aerogel
and into:
1000µm
-3 calculated
-3
experiment
driven
by
Zon0.1gcm
flyer. Lead
SiO2 0.2gcm
aerogel,
to an
givealuminium
pressuresof
SiO
and
1000µm
2 aerogel
release
of
4,
0.4
and
0.2Mbar
respectively.
Shock
samples
of-50%
porosity
will
give
data
in
the
highSiO2 aerogel, calculated to give pressures on
breakouts
areof monitored
VISAR,
active
or from
temperature,
low-density
regime
away
release
4, 0.4
andby
0.2Mbar
respectively.
Shockthe
passive
fibre optic
and the by
pressures
in the
Principal
Hugoniot.
breakouts
areprobes
monitored
VISAR,
active or
release
samples
the impedance
match in the
passive
fibrefound
opticbyprobes
and the pressures
method and assumed Principal Hugoniots. The
release samples found by the impedance match
initial state in the lead base (confirmed by shock
CONCLUSIONS
method SUMMARY
and assumedAND
Principal
Hugoniots. The
velocity measurement at the step and Principal
initial
state
in
the
lead
base
(confirmed
Hugoniot data from HELEN laser experiments),by shock
velocity
measurement
at the Principal
stepvelocity
and Principal
AWE
laser-driven
Hugoniot
the three
release
states
and a free-surface
Hugoniot
datahave
HELEN
experiments),
experiments
anlaser
accuracy
measurement
using
a from
gap reached
and
window
above
the of 1% in
the
three
release
and
atofree-surface
velocity
shock
conventional
methods
lead give
fivevelocity,
points
oncomparable
astates
release
adiabat.
measurement
using aWe
gap
andtens
window
above
the for
at lower pressures.
have
of data
points
lead
giveinfive
on a release
copper
thepoints
10-20Mbar
rangeadiabat.
where only a few
nuclear-driven
points
existed previously. The
POROUS LEAD
HUGONIOT
technique is being applied to lead, and extended to
This
will provisionally
be anpressures
impedance-match
intermediate
and low
(<lMbar) where
POROUS
LEAD
HUGONIOT
experiment
driven by
an aluminium
Z flyer.
Lead
comparison
with
conventional
experiments
can
of
~50%
porosity
will
give
data
in
the
give pressures on release of 4, 0.4 and 0.2Mbar samples
validate
method. be an impedance-match
This the
willlaser
provisionally
errors, but there are clear differences between the high-temperature,
low-density
respectively. Shock breakouts are monitored by
We are driven
beginning
series away
of EOS
experiments
experiment
by anaregime
aluminium
Zfrom
flyer.
Lead
same thicknesses of the three different materials.
Hugoniot.
VISAR, active or passive fibre optic probes and the the Principal
using
the
magnetic
pressure
drive
capability
of Z.
samples of ~50% porosity will give data in the
pressures in the release samples found by the
Initial ICE data have
been taken.
Theaway
behaviour
high-temperature,
low-density
regime
from of
impedance match method and assumed Principal
bulk,
single-crystal
the
Principal
Hugoniot.and alloyed lead has been
Hugoniots. The initial state in the lead base
compared.
(confirmed by shock velocity measurement at the
Future experiments will be done on adiabatic
step and Principal Hugoniot data from HELEN laser
release (where intermediate-pressure HELEN data
81
will be necessary to analyse the data) and on the
Hugoniot of porous lead, which will employ many of
the techniques perfected in the HELEN impedance
match experiments.
ACKNOWLEDGEMENTS
We gratefully acknowledge the vital assistance
and effort of the AWE target fabrication and highprecision machining groups, and the HELEN laser
and Z operations groups. Valuable help and advice
has also been provided by J. Maw, and A.M. Dunne.
© Crown Copyright (2001)
"This document is of United Kingdom origin and
contains proprietary information which is the
property of the Secretary of State for Defence. It is
furnished in confidence and may not be copied, used
or disclosed in whole or in part without prior written
consent of the Director Commercial 2, Defence
Procurement Agency, Ash 2b, MailPoint 88,
Ministry of Defence, Abbey Wood, Bristol, BS34
8JH, England".
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1.
2.
3.
4.
5.
Rothman, S.D. and Evans, A.M., Shock
Compression of Condensed Matter - 1997,
Publisher AIP, eds S.C. Schmidt, D.D.
Dandekar and J.W. Forbes, New York, 1998,
pp. 79-82.
Evans, A.M., Freeman, N.J., Graham, P.,
Horsfield, C.J., Rothman, S.D., Thomas, B.R.
and Tyrrell, A.J., Laser and Particle Beams
14(2), pp. 113-123, (1996).
Hall, C., "Recent Advances in Quasi-Isentropic
Compression Experiments (ICE) on the Sandia
Z Accelerator", these proceedings.
Zel'dovich, Ya. B and Raizer ,Yu. P, Physics of
Shock
Waves
and
High-Temperature
Hydrodynamic Phenomena, Publisher Academic
Press, New York, 1967, pp. 726-730.
"Backward Integration of the Equations of
Motion to Correct for Free Surface
Perturbations", D. Hayes, Sandia Report
SAND2001-1440, 2001. D. Hayes, "Correcting
Free Surface Perturbations by Integrating
Equations of Motion Backward in Space.", these
proceedings.
82