T. C. SangsterUniversity of RochesterLaboratory for Laser Energetics

38th Annual Anomalous Absorption Conference

Williamsburg, VA1–6 June 2008

Status of theOMEGA EP Laser System

The OMEGA/OMEGA EP Laser System is a unique HED research platform

E16808

• TheOMEGAEPprojectwascompletedinApril2008.

• ManyoftheessentialdiagnosticsidentifiedduringaseriesofOMEGAEPusersworkshopswillbeavailablebythestartofoperationsinOctober.

• Asetofnear-termexperimentsisplannedduringthesummer asthefacilityperformancecontinuestoramptodesigngoals.

• Approximately25%oftheshottimeavailableforbasicscience.

Summary

ThecombinedOMEGA/OMEGA EP Laser System willallowawidervarietyofhigh-energy-density physicsexperiments

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• SignificantadvancesinradiographiccapabilitiesforHEDexperiments

• Developmentofdiagnosticsanddiagnostictechniques for the NIF

• Studiesofthefast-ignition concepts

• Additionalprecision HEDphysicsexperiments

• Studiesofultrahigh-intensitylaser–matterinteractions

•Optimizing the use of the NIF throughplatformdevelopment

TheOMEGAEParchitectureisbasedonmulti-configurablebeampaths

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Short pulse

Long pulse

Short pulse

Long pulse

Long pulse

Long pulse

IR Beamline 1

IR Beamline 2

IR Beamline 3

IR Beamline 4 UV xtals and transport

UV xtals and transport

UV xtals and transport

UV xtals and transport

Gratingcompressor

chamber

OMEGA TargetChamber

OMEGA EPTarget

ChamberSwitchyard

Shield wall

NIF-like

OMEGAEPwillachieveitsmissionsusingavarietyof on-targetintensitiesandpulsedurations

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Performance capabilities Short-pulse beam 1 Short-pulse beam 2 Long-pulse

beams 1–4

Target chamber X or EP X or EP EP

Pulsewidth 1–10 ps 10–100 ps 1–80 ps 80–100 ps 1 ns 10 ns

Energy on target (kJ)

1–2.6 (grating limited)

2.60.03–2.6

(combiner limited)

2.6 2.5 6.5

Intensity(W/cm2) 3 × 1020 8 × 1019 2 × 1018 3 × 1016 8 × 1015

Focusing (diam) >80%in20nm >80%in40nm >80%in100nm

Wavelength (nm) 1053 1053 351

SimultaneoussidelightingandbacklightingwillbepossibleinthenewOMEGA EP target chamber

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Backlighterparabola Target

Backlighter2.6kJ, 10 ps

Sidelighter2.6kJ, 10 ps

Diagnostic inserter

Sidelighterparabola

Up to four long-pulseUV beams 10 ns,6.5kJ

ThebeamsfromOMEGAEPwillbefocusedwitha23° f/2off-axisparabolainsidetheOMEGAtargetchamber

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• Afast-focusingopticis necessary to meet the20-nm-diamfocal-spot requirement

• Pointingrequirement inOMEGA:20-nm rms

• 2-hshotcycle (in either chamber)

Cryo equipment

Target

Parabola

Combinedshort-pulse beams2.6kJ 10psand2.6kJ 80ps

OMEGAEPwascompletedon25April2008—onscheduleandonbudget

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OMEGAEPsignificantlyadvancesNNSA’s User Facility capabilities.

OMEGA EP met most of its completion criteria

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• ThemeasuredfocalspotexceedtheR80 = 20 nm requirement –operationalexperiencewillreducethefocalspotsize

• TheremainderofFY08willbeusedtogainoperationalexperience andperforminitialexperiments

OMEGAEPfired22targetshotstotheOMEGAchamberinfourdays.

OMEGA EP performance to the OMEGA target chamber

Criteria Beamline 1 Beamline 2

Co-propagatingpulseduration 84ps 9.5ps

On target energy 630 J 460J

Co-timingtoOMEGA 6-psrms 6-psrms

Focal spot (R80) 33 nm

Timebetweenshots 1.7 h 1.7 h

Pointing stability 2.8-nradrms 3.0-nradrms

10

TheOMEGAEPcompressorsanddiagnosticswere themosttechnicallychallengingaspectoftheproject

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Fourtiled-gratingassemblies(TGA’s) of the upper compressor areshownwithancillaryopticsfortransportanddiagnostics.

TGA2

TGA3

TGA4

TGA1

10

“Subpicosecondcompression”wasachieved atvacuumfor5-HzOPCPAbeams

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Lessthan1-pspulsewidthachievedonbothcompressors fortiledgratingsinvacuum.

Autocorrelator tracefor lower compressor

AC FWHM= 888 fs

AC FWHM= 800 fs

–3 –2 –1 0ps

1 2 3 –3 –2 –1 0ps

1 2 3

Autocorrelator tracefor upper compressor

AvgSmoothed

AvgSmoothed

No

rmal

ized

inte

nsi

ty

No

rmal

ized

inte

nsi

ty

Thefocal-spotdiagnostic(FSD) is a novelsystemcapableofon-shotspotcharacterization

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• TheFSDconcept

– calculatetheon-targetfocalspotfrommeasurementsthatgive theon-shotamplitudeandwavefrontattheOAP

1.Pre-shotcalibration2.On-shotmeasurement3.Post-shotcalculation

ThreestepsrequiredbyFSD

Focal spot

Log scale (4 decades)

Wavefront

Multiplefocal-spotmeasurementsindicatean average R80valueof34nm

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00.0

0.2

0.4

0.6

0.8

1.0

En

cirl

ed e

ner

gy

Radius (nm)

80604020

R80 = 32.5 nm

R60 = 24.7 nm

R40 = 19.9 nm

R20 = 12.7 nm

–4

–3

–2

–1

0

0x (nm)

200100–200 –100

y (n

m)

–200

–100

200

0

100

Focal spot (log scale)

R80R80

Measured Criteria

33.0 nm

20.0 nm35.5nm

32.5nm

OMEGAEPshort-pulseenergieswillberamped tofullcapabilityduringFY09

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10-ps activationenergy

1001010

1500

2000

3000

2500

1000

500

0

Energy on target versus pulse width

Sh

ort

-pu

lse

EO

T (

J)

Pulse width (ps)

270 J140 J

760 J

1.0 PW

0.5 PW

2.6 kJ

1.35 kJ

Full backlighter capability

Full sidelighter capability

Initial sidelighter limit

Initial backlighter limit

100-ps activationenergy

Anumberoflong-andshort-pulsediagnostics willbeavailableonOMEGAEP

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• Long-pulseUVdiagnostics

– framingcamera,pinholecamera,spectrometer(TIMbased)

– x-rayCCDcamera,x-raystreakcamera(TIMbased)

– fixedpinholecamera(CIDreadout,done)

–HXRD(designstarted,completeFY08)

–ASBO/SOP (designstarted,completeFY09)

• Short-pulsediagnostics

– single-photon-counting(designstarted,completeFY08)

– opticaltransitionradiationdiagnostic(plannedforFY09)

–K-shellspectroscopy(plannedforFY09)

– softx-raydiodes(plannedforFY09)

– neutrondetector(done)

– x-raymonitor(done)

– EMPmonitor(done)

– radiationmonitor(95%done)

AseriesofOMEGAEPUsePlanningworkshopswasheld

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• January2006—Developprioritiesforcapabilitydevelopment – over50externaluserparticipants(national laboratory, university,andforeign) –workinggroupssuggested - fastignition - short-pulse,hard x-raysourcesanddetectors - ionsources - long-pulsedynamicloading - isochoricheatingofwarmdensematter - backlightimplosions

• May2007—Begandetailedexperimentalplanning – first100shotsdefined

• April2008—Detailedexperimentalplanning – targetdesignandlaserconfiguration

16

Target Goal Diagnostics Number of Shots

Fast Ignition: SandwichplanartargetsAl/Cu/Al,Al,freestudy

Electron/protonproductiontemperaturewith10-ps pulses Ka spectroscopy 15

CHfoilwithwitnesslayer Initial channeling X-ray imaging, transmittedlight 5

Hardx-ray, WDM: AgandSmfoil/flag/wire,resolutiongrid

Hardx-rayandkeVbroadband

50~100micspots,x-ray spectometers, imagers 15

High-brightnesskeVsources:F~Si materials, foams, colloidaltargets

High brightness for ICF backlighting

keVx-ray spectrometer,x-raystreakcamerawithspectrometer

10

Long-pulsebacklighting:Thickfoil(pinhole for PPB) Develop capability X-raystreak 5

Low-andhigh-Z ions:Thin foil Develop capability Optical pyrometer,

heating source, RCF 5

HED materials:Thin Al/Si02 foil Initialshockvelocity ASBO/VISAR 10

Al foil Direct measure of Al EOS Hard x-ray source anddetector 5

WDM:Planar foil Double/collidingshock SOP 5

ICF:Planar foil Initial scale length FABS,HXRD4~ probe 5

ComplexHydro:Washers/foam Initialepisodicjet X-rayimage 5

D3He proton source:Explodingpusher Monoenergetic proton source WRF 2

High-intensity physics:Planarfoil,gasjet

Magnetic-field+ MeVphoton generation

Photondiagnostic,photon beam, nuclear activation

10

ApproximatelyhalfoftheOMEGAEPUsers’ShotPlanwillbeexecutedinFY08

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Nearly25%oftheshottimeonOMEGAEP willbedevotedtobasicscience

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Category SubdivisionFY09NotionalAllocation

%* OMEGAShots** OMEGAEPShots**

National Ignition Campaign

IDIDDI

1040

105420

45180

HED LLNLandLANL

20 210 90

Basic Science NLUFLaboratory

1312

136126

5854

Contingency 5 53 23

Total 100 1050 450

TheFY09schedulewillbedeterminedby1July2008.

*AllocationrecommendedbyFSACinJune2007andapprovedbyLLEDirector.**Shotavailabilityatfulloperationsfunding.

• TheOMEGAEPprojectwascompletedinApril2008.

• ManyoftheessentialdiagnosticsidentifiedduringaseriesofOMEGAEPusersworkshopswillbeavailablebythestartofoperationsinOctober.

• Asetofnear-termexperimentsisplannedduringthesummer asthefacilityperformancecontinuestoramptodesigngoals.

• Approximately25%oftheshottimeavailableforbasicscience.

The OMEGA/OMEGA EP Laser System is a unique HED research platform

E16808

Summary/Conclusions