Time-Resolved Measurement of Optical Self-Emissionfor Shock Wave and Equation of State Studies

J. E. MillerUniversity of RochesterLaboratory for Laser Energetics

46th Annual Meeting of theAmerican Physical SocietyDivision of Plasma Physics

Savannah, GA15–19 November 2004

SOP Shot 32208

0 2 4 6

Dis

tan

ce (µm

)

Time (ns)

–500

0

5001st shock

CoalescenceBreakout

Collaborators

W. J. Armstrong, T. R. Boehly, I. V. Igumenshchev,D. D. Meyerhofer, W. Theobald, and E. Vianello

Laboratory for Laser Energetics, University of Rochester

J. Eggert, D. G. Hicks, and C. Sorce

Lawrence Livermore National Laboratory

E13376

Simulations of cryogenic D2 experiments agree wellwith observations made utilizing the SOP

• The streaked optical pyrometer (SOP) is a time-resolved,self-emission diagnostic1 recently configured to runsimultaneously with VISAR.2

• Spatial and temporal calibration of SOP recordshave been verified with VISAR.

• Temperature measurements using the absolute spectralcalibration are useful in evaluating EOS models.

• Optical self-emission will be a key diagnosticof future shaped-pulse work.

1 J. A. Oertel et al., Rev. Sci. Instrum. 70, 803 (1999).2 Velocity Interferometer System for Any Reflector

Summary

Optical self-emission data are acquired simultaneouslywith shock velocity from VISAR

Mag = 13×DoF ~ 3 mmδx = 7.75 µm

VISAR’s

1 2

OMEGA

SOPf/3.3

E13377

SOP spectral response

1000 2000 30000Wavelength (nm)

100

1

0.01

Sp

ectr

al r

adia

nce

(W/m

m2 /

nm

)

4.5 eV

0.25 eV

E13378

Shock coalescence in multi-shock experimentsis detected in self-emission temporal records

Time (ns)

~3 × 1014 W/cm2

90 ps

500

0

–500

SOP Shot 32217

0 2 4 6

Coalescence

Breakout

Time (ns)

Dis

tan

ce (µm

)

Inte

nsi

ty

0.0 0.5 1.0 1.5 2.0 2.5

23°

48° CH

E13379

The SOP provides excellent shock timing agreementwith VISAR resulting in a reliable measure of 2-D effects

Shot 32217 ShockCoalescence and Breakout

VISARSOP

Coalescence Breakout

3.0 3.5 4.0 4.5 5.0 5.5 6.0

Time (ns)

400

200

0

–400

–200Dis

tan

ce (µm

)

ASBO Shot 32217

SOP Shot 32217

500

0

–500

0 2 4 6

Coalescence

Breakout

Dis

tan

ce (µm

)

Time (ns)

500

0

–500

0 2 4 6

Coalescence

Breakout

Dis

tan

ce (µm

)

E13381

The SOP spectral response was absolutely calibrated*to relate SOP output to brightness temperature

* Using the NIST-Traceable Standard OL-550

100

10

1

0.1SR

(m

ean

AD

U/W

/mm

2 ) 10

8

6

4

2

0

Tem

per

atu

re (

eV)

0.6 0.7 0.8 0.9 0 5000 10000 15000

Wavelength (µm) SOP output (mean ADU)

Filter edge

Phototcathode

Black-Body TemperataureDependence of SOP Output

Spectral Response Functionof the SOP

SOP SOP

Black Body

E13382

Equation of state studies involve the simultaneousmeasurements of reflectivity, shock velocityand self-emission data

10 15 20 25 30 35Shock velocity (µm/ns)

0

2000

4000

6000

8000

0.0

0.1

0.2

0.3

0.4

Ref

lect

ivit

y

SO

P o

utp

ut

(mea

n A

DU

)

∝- Quartz Reflectivity andSOP Output Shock

Strength Dependence

TBB

VISARReflectivity

Velocity

TGB

SOP

Shockat TGB

E13383

The measured shock temperature can be usedto evaluate EOS models of pusher materialsfor shock timing experiments

* G. Kerley, “Equations of State for Composite Materials”,SANL Report KPS 99-4 (1999).

α – Quartz Temperature Shock Strength Dependence7

4

6

5

1

2

Tem

per

atu

re (

eV)

Shock velocity (µm/ns)

20 2515

3 LEOS 2210Kerley*Measured

E13529

Shock coalescence in multi-shock experiments of D2is detected in self-emission temporal records

Time (ns)

~3 × 1014 W/cm2

90 ps

Dis

tan

ce (µm

)

–500

500

0

SOP Shot 36457

0 2 4 6 8

Time (ns)

Coalescence

Inte

nsi

ty

0.0 0.5 1.0 1.5 2.0 2.5

23°

48° Cryo D2

Simulations of cryogenic D2 shock coalescenceagrees well with observations made with the SOP

200

0

–200

ASBO Shot 36457

0 5

E13380

Observed and SimulatedCoalescence Times in Cryogenic D2

ObservedLILAC

Drive-pulse delay (ns)

1.0 1.50.5 2.0 2.5 3.0 3.5 4.0 4.5

Tim

e (n

s)

0

1

2

3

4

5

6

7

Dis

tan

ce (µm

)

500

0

–500

SOP Shot 36457

0 2 4 6 8Time (ns)

Dis

tan

ce (µm

) Coalescence

E13501

The SOP is a potential diagnostic for shock timingstudies of ICF-relevant shaped pulses in D2

SOP temperaturemeasurementscan be made.

Po

wer

Time (ns)

0 1 2 3 4

SOP can beused to inferfoot pulse andcompressionwavecoalescence.

ICF-Relevant Shaped α = 4 Pulse

E13376

Simulations of cryogenic D2 experiments agree wellwith observations made utilizing the SOP

• The streaked optical pyrometer (SOP) is a time-resolved,self-emission diagnostic1 recently configured to runsimultaneously with VISAR.2

• Spatial and temporal calibration of SOP recordshave been verified with VISAR.

• Temperature measurements using the absolute spectralcalibration are useful in evaluating EOS models.

• Optical self-emission will be a key diagnosticof future shaped-pulse work.

1 J. A. Oertel et al., Rev. Sci. Instrum. 70, 803 (1999).2 Velocity Interferometer System for Any Reflector

Summary/Conclusions