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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

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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

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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

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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

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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

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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

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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

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• 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

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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.

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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

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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”

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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

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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

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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 - 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]