Science outreach on NIF: possibilities
for astrophysics experiments
Presentation to the SABER workshop,
Stanford Linear Accelerator Center,
March 15-16, 2006
Bruce A. Remington
Group Leader, HED Program
Lawrence Livermore National Laboratory
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Intro
We are implementing a plan for university use of NIF
fy05
fy06
Start 3 university
teams
fy07
fy08
fy09
fy10
fy11
fy12
Develop full-NIF
univ. use proposals
Add 1-2 university teams/year
Select, prepare for 1st
univ. use experiment
Issues:
Start university experiments
• funding for the universities
(goal: ~10% of NIF shots)
• targets
• coordination with the other facilities
- Omega/NLUF, Z/ZR, Jupiter, Trident, …
• proposal review committee
- assess science impact, facility capability, readiness
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Intro
Three university teams are starting to prepare
for NIF shots in unique regimes of HED physics
Astrophysics hydrodynamics
Paul Drake, PI, U. of Mich.
David Arnett, U. of Arizona,
Adam Frank, U. of Rochester,
Tomek Plewa, U. of Chicago,
Todd Ditmire, U. Texas-Austin
LLNL hydrodynamics team
Planetary
physics - EOS
Raymond Jeanloz, PI, UC Berkeley
Thomas Duffy, Princeton U.
Russell Hemley, Carnegie Inst.
Yogendra Gupta, Wash. State U.
Paul Loubeyre, U. Pierre & Marie
Curie, and CEA
LLNL EOS team
Nonlinear optical
physics - LPI
Chan Joshi, PI, UCLA
Warren Mori, UCLA
Christoph Niemann,
UCLA NIF Prof.
Bedros Afeyan, Polymath
David Montgomery, LANL
Andrew Schmitt, NRL
LLNL LPI team
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Astrophysics
Supernova experiments on NIF will address
the core penetration discrepancy in SN1987A
Jet model
• Simulations do not reproduce
observed core penetration velocities
Spherical shock model
He
Core
H
Core
5 x 1011cm
9 x 109cm
Shock
front
SN1987A
Kifonidis,
Ap. J. Lett 531,
L123 (2000)
Khokhlov,
Ap. J. 524,
L107 (1999)
Density
6 x 109cm
• Does He shell breakup allow core spikes to escape?
• Are differences in 3D vs 2D spike velocities important?
• How do 3D perturbations on multiple interfaces interact?
• How does the initial perturbation spectrum affect the late-time evolution?
[Courtesy of R. Paul Drake et al.]
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Astrophysics
The SN team is designing a divergent RT
experiment for NIF to address these SN issues
g/cc
t = 0 ns
t = 50 ns
0.40
0.35
Light foam
 = 0.05 g/cc
0.30
0.25
Laser
Core
Heavy foam
 = 0.5 g/cc
Ti shell (core)
 = 4.5 g/cc
1 mm
0.20
0.15
0.10
gas
 = 5.0e-5 g/cc
1 mm
0.05
0.00
[Simulations by Aaron Miles (2004)]
• Mass-scaled to SN with representative Core/He, He/H, and H/ISM interfaces
• Designed to address issues of: multi-interface interaction, divergence, initial
conditions, 3D vs 2D, turbulent vs non-turbulent instability evolution, code validation
• Can be scaled up in size, energy, and complexity, as NIF evolves
[Courtesy of R. Paul Drake et al.]
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Astrophysics
NIF has already demonstrated nonlinear, shock
driven, 3D hydrodynamics experiments
3D perturbation
2D perturbation
Triple
point
Mach
reflection
v2
Transmitted
shocks
v1
Hole
rarefaction
Shocks
Aluminum
Reflected
shock
2D jet @ t = 22 ns
200 um
Velocity
discontinuity
3D jet @ t = 22 ns
200 um
[Brent Blue et al., PRL 94, 095005 (2005); PoP 12, 056313(2005)]
200 um
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He drop
formation?
7700 GPa
16000 K
Fluid metallic
H + He
200 GPa
5300 K
Ices?
Phase
separation?
Internal energy, E/(K0V0)
Fluid H2 + He
102 ~ keV
100
K0= Bulk modulus:
~ eV
1.5
10-2
Key Questions:
• Equation of state near the planetary isentropes
• Location of the insulating-conducting transition
Super
giants
104
Ice crystals
Jupiter
High pressure experiments on NIF will address key
questions regarding the internal structure of Jupiter
Earth
Planetary phys.
1.1
2.0
100
~ 1 Mbar at P = 0
Pre-compression, /0
~Mbar
10-1
3.0
~Gbar
101
102
103
Pressure, P/K0
104
• Melt line at high pressure
• Existence of a plasma phase transition (PPT)
• Does He and H2 phase separate in Jupiter/Saturn
[Courtesy of Raymond BAR_SBER_talk.ppt;7
Jeanloz et al.]
Planetary phys.
Coupling NIF with DAC targets will enable
key measurements of planetary interior states
Shocks with
precompression
Omega
104
Temperature (K)
Ramp-wave compression
on NIF
quartz
plate
sample
LIL
NIF
Visar
103
High energy
laser
102
0
•
•
•
•
100
200
Pressure (GPa)
300
Pre-compression is the only way to study dense He+H2 mixtures
The PPT accessed with pre-compressions > 1 GPa
Melt curve maximum accessed with pre-compressions ~ 30 GPa
Ramp wave compression may allow planetary core conditions to be accessed
[Courtesy of Raymond BAR_SBER_talk.ppt;8
Jeanloz et al.]
The NIF VISAR diagnostic and pulse shape have been
demonstrated for possible shock EOS experiments
0.8
Quartz
Al baseplate
Total power (TW)
Planetary phys.
Preheat shield
Ablator
NIF drive
0.6
0.4
NEL pulse shape designed
to produce a 23 Mbar
steady shock in Cu
0.2
NIF VISAR trace (2004)
0
1
2
Predicted breakout profile
Shock Vel. (km/s)
Time (ns)
10
0
8
6
-400
-200
0
200
Position (m)
3
4
Time (ns)
5
30
20
10
Shock msmt in
quartz window on NEL
400
[Courtesy of Raymond Jeanloz et al.]
7
8
Time (ns)
9
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Nonlin. opt’l
Nonlinear interactions of intense laser beams in large scale
plasmas is a scientific challenge of considerable importance
Single beam, I > Ithr, t = 312 0/cs
2000
z/0
z/0
Single beam, I > Ithr, t = 0
2000
1000
0
1000
0
0
x/0
500
I < Ithr, single-beam
simulation, no filamentation
Beam 1
[Schmitt & Afeyan,
PoP 5, 503 (1998)]
0
x/0
500
I < Ithr, sub-thresh. crossing beams can filament,
due to interactions with IAW fluctuations
Beam 1
Without
interacting
beams
• Filamentation strongly affects the initiation and evolution of
SRS and SBS backscatter, as well as beam pointing
[Courtesy of
Andy Schmitt &
Bedros Afeyan
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Nonlin. opt’l
NIF will allow experiments probing the interaction of multiple
beams in large scale plasmas over a wide range of (ne,Te)
• HYDRA simul’s show that high plasma
temperatures (Te = 3-6 keV) and densities
(ne =0.1 critical) can be achieved
• Crossing beams will allow non-resonant effects
on SRS backscatter to be studied with good
speckle statistics
Early time:
driver beams
explode foil
driver
beams
• NIF’s versatile pulse-shaping will greatly expand
the design space for exploding foil targets
Laser pulse shapes
Laser intensity
x 1015 (W/cm2)
red =“hot case”
2
1
Late time:
probe beams
interact with
drive beams
and long, hot
plasma.
black=“cool case”
probe
beams

driver
beams
0
0
2
Time (ns)
4
[Courtesy of Chan Joshi et al.]
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Nonlin. opt’l
The FABs and NBI diagnostics have already measured
angularly resolved scattered energy with high precision on NIF
1.2 kJ SBS out side lenses
153 J in lenses
130 J SRS out side lenses
38 J SRS in lenses
(High temperature hohlraum target experiment)
[Glenzer et al., Nucl. Fusion 44, S185 (2004)]
[Courtesy of Chan Joshi et al.]
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Summary
Our vision for university use of NIF is to coordinate
with the other HED facilities in a staged approach
• Test out new ideas, develop new techniques, on smaller facilities, such as Janus,
Trident, Titan, Vulcan, Helen, Cornell X-pinch, Nevada Terawatt Facility, Magpie, …
Example: Collins, Jeanloz et al., laser-DAC experiments on Vulcan
• Promising ideas move to major HED facilities, such as Omega, Z/ZR, Saturn,
LIL, … for demonstration on “big machines”:
Examples of Omega / NLUF:
“Optical Mixing Controlled Stimulated Scattering Instabilities,” Bedros B. Afeyan et al.
“Recreating Planetary Core Conditions on Omega,” Raymond Jeanloz et al.
“Experimental Astrophysics on the Omega Laser,” R. Paul Drake et al.
• Those experiments requiring high energy “conclusion points” then propose to NIF
• Informal coordination between the facilities appears possible
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HED laboratory astrophysics allows unique, scaled testing of
models of some of the most extreme conditions in the universe
• Stellar evolution: opacities (eg., Fe) relevant to stellar envelopes;
Cepheid variables; sellar evolution models; OPAL opacities
• Planetary interiors: EOS of relevant materials (H2, H-He, H20, Fe)
under relevant conditions; planetary structure - and
planetary formation - models sensitive to these EOS data
• Core-collapse supernovae: scaled hydrodynamics demonstrated;
turbulent hydrodynamics within reach; aspects of the
“standard model” being tested
• Supernova remnants: scaled tests of shock processing of the ISM;
scalable radiative shocks within reach
• Protostellar jets: relevant high-M-# hydrodynamic jets;
scalable radiative jets, radiative MHD jets;
collimation quite robust in strongly cooled jets
• Black hole/neutron star accretion disks:
scaled photoionized plasmas within reach
• Our goal: to be citius, altius, fortius, sapientius for laboratory astrophysics
[Roger Blandford, keynote address, HEDLA-04]
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