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BAR_SBER_talk.ppt;1 Science outreach on NIF: possibilities for astrophysics experiments Presentation...
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Transcript of BAR_SBER_talk.ppt;1 Science outreach on NIF: possibilities for astrophysics experiments Presentation...
BAR_SBER_talk.ppt;1
Science outreach on NIF: possibilities for astrophysics experiments
Presentation to the SABER workshop,Stanford Linear Accelerator Center,
March 15-16, 2006
Bruce A. RemingtonGroup Leader, HED Program
Lawrence Livermore National Laboratory
BAR_SBER_talk.ppt;2
fy05 fy06 fy07 fy08 fy09 fy10 fy11 fy12
We are implementing a plan for university use of NIF
Start 3 university teams
Add 1-2 university teams/year
Start university experiments(goal: ~10% of NIF shots)
Issues:• funding for the universities• targets• coordination with the other facilities
- Omega/NLUF, Z/ZR, Jupiter, Trident, …• proposal review committee
- assess science impact, facility capability, readiness
Select, prepare for 1stuniv. use experiment
Intro
Develop full-NIF univ. use proposals
BAR_SBER_talk.ppt;3
Astrophysics -hydrodynamics Planetary
physics - EOS
Nonlinear opticalphysics - LPI
Three university teams are starting to prepare for NIF shots in unique regimes of HED physics
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
Raymond Jeanloz, PI, UC BerkeleyThomas Duffy, Princeton U.Russell Hemley, Carnegie Inst.Yogendra Gupta, Wash. State U.Paul Loubeyre, U. Pierre & Marie
Curie, and CEALLNL EOS team
Chan Joshi, PI, UCLAWarren Mori, UCLAChristoph Niemann,
UCLA NIF Prof.Bedros Afeyan, PolymathDavid Montgomery, LANLAndrew Schmitt, NRLLLNL LPI team
Intro
BAR_SBER_talk.ppt;4
6 x 109cm5 x 1011cm
Supernova experiments on NIF will address the core penetration discrepancy in SN1987A
Spherical shock modelShock front
Jet model
Khokhlov, Ap. J. 524, L107 (1999)
9 x 109cm
Density
Kifonidis,Ap. J. Lett 531, L123 (2000)
• 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.]
HHe
SN1987A
Astrophysics
• Simulations do not reproduce observed core penetration velocities
Core
Core
BAR_SBER_talk.ppt;5
The SN team is designing a divergent RT experiment for NIF to address these SN issues
• 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.]
Laser
t = 50 ns
1 mm
[Simulations by Aaron Miles (2004)]
g/cc
0.40
0.35
0.30
0.25
0.20
0.15
0.10
0.05
0.00
t = 0 ns
Ti shell (core) = 4.5 g/cc
Heavy foam = 0.5 g/cc
Light foam = 0.05 g/cc
gas = 5.0e-5 g/cc
1 mm
Astrophysics
Core
BAR_SBER_talk.ppt;6
Transmitted shocks
Reflected shock
rarefaction
Machreflection
Triplepoint
Velocitydiscontinuity
3D perturbation2D perturbation
ShocksHole
Aluminum
v1
v2
2D jet @ t = 22 ns 3D jet @ t = 22 ns
200 um 200 um 200 um
[Brent Blue et al., PRL 94, 095005 (2005); PoP 12, 056313(2005)]
NIF has already demonstrated nonlinear, shock driven, 3D hydrodynamics experiments
Astrophysics
BAR_SBER_talk.ppt;7
Ice crystals
Fluid H2 + He
Fluid metallic H + He
Phaseseparation?
Ices?
200 GPa5300 K
7700 GPa16000 K
He drop formation?
High pressure experiments on NIF will address key questions regarding the internal structure of Jupiter
Key Questions:
• Equation of state near the planetary isentropes
• Location of the insulating-conducting transition
• Melt line at high pressure
• Existence of a plasma phase transition (PPT)
• Does He and H2 phase separate in Jupiter/Saturn[Courtesy of Raymond Jeanloz et al.]
Pre-compression,
K0= Bulk modulus:
~ 1 Mbar at P = 0
Pressure, P/K0
10-1 100 101 102 103 104In
tern
al e
ner
gy,
E
/(K
0V0)
104
102
100
10-2 1.1
1.52.0
3.0
~Mbar ~Gbar
~ keV
~ eV
Ear
th
Jup
iter
Su
pe
rg
ian
ts
Hugoniot
Planetary phys.
Isentrope;
planetary interio
rs
BAR_SBER_talk.ppt;8
• 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
quartzplate
sample
Visar
High energy laser
NIF
LILOmega
Coupling NIF with DAC targets will enable key measurements of planetary interior states
Ramp-wave compression on NIF
Pressure (GPa)0 100 200 300
Tem
per
atu
re (
K)
104
103
102
[Courtesy of Raymond Jeanloz et al.]
Planetary phys.
Melt crv
PPT (Saumon)
PPT (Bonev)
Shocks with precompression
Neptune
Jupiter
BAR_SBER_talk.ppt;9
The NIF VISAR diagnostic and pulse shape have been demonstrated for possible shock EOS experiments
Predicted breakout profile
NIF VISAR trace (2004)
Position (m)-400 -200 0 200 400
Tim
e (n
s)
10
8
6
Al baseplate
Ablator
Preheat shield
NIF drive
Quartz
Time (ns)
Sh
oc
k V
el.
(km
/s)
7 8 9
30
20
10
Shock msmt in quartz window on NEL
[Courtesy of Raymond Jeanloz et al.]
Time (ns)0 1 2 3 4 5
To
tal
po
wer
(T
W)
0.8
0.6
0.4
0.2
0
NEL pulse shape designed to produce a 23 Mbar
steady shock in Cu
Planetary phys.
BAR_SBER_talk.ppt;10
Single beam, I > Ithr, t = Single beam, I > Ithr, t = 312 0/cs
I < Ithr, single-beam simulation, no filamentation
I < Ithr, sub-thresh. crossing beams can filament, due to interactions with IAW fluctuations
0 x/0 500
2000
z/ 0 1000
00 x/0 500
[Courtesy of Andy Schmitt &Bedros Afeyan
[Schmitt & Afeyan, PoP 5, 503 (1998)]
Nonlinear interactions of intense laser beams in large scale plasmas is a scientific challenge of considerable importance
Without interactingbeams
Beam 1
• Filamentation strongly affects the initiation and evolution of SRS and SBS backscatter, as well as beam pointing
Beam 1
Bea
m 2
Nonlin. opt’l
2000
z/ 0 1000
0
BAR_SBER_talk.ppt;11
driver beams
Early time:
driver beams explode foil
Late time:
probe beams interact with drive beams and long, hot plasma.
probe beams
driver beams
black=“cool case”
Time (ns)0 2 4
Las
er in
ten
sity
x 10
15 (
W/c
m2 )
0
1
2
• NIF’s versatile pulse-shaping will greatly expand the design space for exploding foil targets
• 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
[Courtesy of Chan Joshi et al.]
NIF will allow experiments probing the interaction of multiple beams in large scale plasmas over a wide range of (ne,Te)
Nonlin. opt’l
Laser pulse shapes
red =“hot case”
BAR_SBER_talk.ppt;12
1.2 kJ SBS out side lenses153 J in lenses
130 J SRS out side lenses38 J SRS in lenses
(High temperature hohlraum target experiment)
The FABs and NBI diagnostics have already measured angularly resolved scattered energy with high precision on NIF
[Glenzer et al., Nucl. Fusion 44, S185 (2004)]
[Courtesy of Chan Joshi et al.]
Nonlin. opt’l
BAR_SBER_talk.ppt;13
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
Summary
BAR_SBER_talk.ppt;14
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 - andplanetary 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]