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NNSA Perspectiveon Scientific Opportunities in

High Energy Density Laboratory Plasma Physics

Mike DonovanActing Director, ICF Program

August 25, 2008

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Why does NNSA care about HEDLP?

NNSA Interests: Possessing validated predictive nuclear weapons codes

• Stockpile confidence• Stockpile maintenance costs• Without nuclear explosive tests

Understanding the science to build those codes• Material properties• Shock physics• Equations of State• Transport coefficients• Collective effects in mixing• . . .

High quality scientists in NNSA laboratories for classified and applied weapons work

NNSA needs advances in fundamental and applied

high energy density science

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Why academic and private researchers?

Have an institutional focus on creative discovery science

Are independent of the NNSA methods and conclusions

Live in a world of open, vigorous peer review

Make NNSA laboratory scientists better by competing

Develop the knowledge to provide peer reviews to nuclear weapons scientists

Some will become the next generation of lab scientists

Lab and non-Lab researchers are

complementary

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NNSA agrees with HEDSA* positions

• Intermediate and small scale facility research provides the greatest benefit at this time

• Large facility research could be appealing in a collaborative mode in the future with the maturation of HEDLP

• Access to computational hardware and software would assist in the progress of this research

• The best proposals should be funded over a broad range of HEDLP topics

*HEDSA: High Energy Density Science Association

For academic and private research in the HEDLP Joint Program:

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Examples of recent HEDLP research that is valuable to NNSA objectives

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Precompression of materials extends the phase space that can be explored

• The Equation of State of compressed H and He are explored in R. Jeanloz (UCBerkeley) NLUF program• These results are important to understand the interiors of the giant gas planets• NNSA is interested in extending its understanding of materials properties under extreme conditions Diamond Anvil Cell Target

Shock compression of He with different initial densities*

* J. Eggert, PRL 100, 124503 (2008)

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Dynamic properties of shocked crystals are important to NNSA’s mission

• M. A. Myers (UCSD) is PI for an NLUF grant to study dynamic materials properties – in collaboration with U.C. Davis, LLNL, Oxford, LANL, LLE

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Multiview tomographic diagnostics are being developed on OMEGA

• R. Mancini (UNR), with LLNL and LLE, is developing tomographic diagnostics through NLUF

• This work promises further understanding of ICF implosions

Reconstructed images

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Monoenergetic proton radiography – a versatile diagnostic tool for ICF and HED experiments

• R. Petrasso et al. (MIT) is developing monoenergetic proton radiography on OMEGA with a NLUF grant

Measurements of transient electromagnetic fields on OMEGA

Charged particles from nuclear reactions

probe the fields in a target

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Cornell’s Pulsed-power-drivenHED Laboratory Plasma Studies Center

Mission• Advance understanding of HED plasma physics• Develop new HED diagnostics, e.g., X-ray

backlighting, time-gated imaging, magnetic fields• Be available as a user facility • Help develop intense x-ray sources• Investigate novel HED plasma configurations• Train the next generation of HED scientists

Cylindrical Wire Arrays

Radial Wire Array

Three of 4 X-pinch x-ray backlighter images (from a single wire-array z-pinch pulse), and a current trace with the x-ray signals showing X-pinch timing

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Efficient X-ray conversion with wire-arrays is being studied on small Z-pinches

0

20

40

-1 .00E -08 4 .00E -08 9 .00E -08 1 .4 0E -07 1 .9 0E -07

Time (ns)

x-ra

y P

ow

er (

a.u

.)

0 .0 4

0 .5 4

1 .0 4

Cu

rren

t (M

A)

0 50 100 150 200

5ns

• Nested quadruple array

V.V. Ivanov at al., Phys. Rev. Lett. 100, 025004 (2008)

• Star-like arrays produce powerful short x-ray pulses

• Star-like arrays have small shot-to-shot variations

0.2

0.3

0.4

0.5

20 70 120 170linear mass, µg/cm

x-r

ay

po

we

r (T

W)

3-ray star 8-ray star

• Implosion in star-like arrays cascades from wire to wire

Star 16 / 12 / 8 / 6 mm, 12 x 12µm

Results from star-like arrays from the Nevada Terawatt Facility (2 TW Z Pinch)

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KEEN waves constitute a new form of plasma self-organization driven by optical mixing and

detected on Trident

0

0.2

0.4

0.6

0.8

1

1.2

1.4

0 0.1 0.2 0.3 0.4 0.5 0.6

/

p

kD

697 nm

600 nm

He

N2 / H2

Montgomery LANLCH

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Summary

NNSA needs advances in fundamental and applied

high energy density science