Expanding the Periodic Table Summer Students Engage in ......More information about LLNS is...

L a w r e n c e L i v e r m o r e N a t i o n a l L a b o r a t o r y

Livermore Wins6 R&D 100

Awards

October/November 2010

Also in this issue:

ExpandingthePeriodicTable

SummerStudentsEngageinDiverseResearch

AbouttheCover

AboutS&TR

AtLawrenceLivermoreNationalLaboratory,wefocusonscienceandtechnologyresearchtoensureournation’ssecurity.Wealsoapplythatexpertisetosolveotherimportantnationalproblemsinenergy,bioscience,andtheenvironment.Science & Technology Reviewispublishedeighttimesayeartocommunicate,toabroadaudience,theLaboratory’sscientificandtechnologicalaccomplishmentsinfulfillingitsprimarymissions.Thepublication’sgoalistohelpreadersunderstandtheseaccomplishmentsandappreciatetheirvaluetotheindividualcitizen,thenation,andtheworld. TheLaboratoryisoperatedbyLawrenceLivermoreNationalSecurity,LLC(LLNS),fortheDepartmentofEnergy’sNationalNuclearSecurityAdministration.LLNSisapartnershipinvolvingBechtelNational,UniversityofCalifornia,Babcock&Wilcox,WashingtonDivisionofURSCorporation,andBattelleinaffiliationwithTexasA&MUniversity.MoreinformationaboutLLNSisavailableonlineatwww.llnsllc.com. Pleaseaddressanycorrespondence(includingnameandaddresschanges)toS&TR,MailStopL-664,LawrenceLivermoreNationalLaboratory,P.O.Box808,Livermore,California94551,ortelephone(925)[email protected]&TRisavailableontheWebatstr.llnl.gov.

©2010.LawrenceLivermoreNationalSecurity,LLC.Allrightsreserved.ThisworkwasperformedundertheauspicesoftheU.S.DepartmentofEnergybyLawrenceLivermoreNationalLaboratoryundercontractDE-AC52-07NA27344.Torequestpermissiontouseanymaterialcontainedinthisdocument,pleasesubmityourrequestinwritingtoPublicAffairsOffice,LawrenceLivermoreNationalLaboratory,MailStopL-3,P.O.Box808,Livermore,California94551,[email protected].

ThisdocumentwaspreparedasanaccountofworksponsoredbyanagencyoftheUnitedStatesGovernment.NeithertheUnitedStatesGovernmentnorLawrenceLivermoreNationalSecurity,LLC,noranyoftheiremployeesmakesanywarranty,expressedorimplied,orassumesanylegalliabilityorresponsibilityfortheaccuracy,completeness,orusefulnessofanyinformation,apparatus,product,orprocessdisclosed,orrepresentsthatitsusewouldnotinfringeprivatelyownedrights.Referencehereintoanyspecificcommercialproduct,process,orservicebytradename,trademark,manufacturer,orotherwisedoesnotnecessarilyconstituteorimplyitsendorsement,recommendation,orfavoringbytheUnitedStatesGovernmentorLawrenceLivermoreNationalSecurity,LLC.TheviewsandopinionsofauthorsexpressedhereindonotnecessarilystateorreflectthoseoftheUnitedStatesGovernmentorLawrenceLivermoreNationalSecurity,LLC,andshallnotbeusedforadvertisingorproductendorsementpurposes.

PreparedbyLLNLundercontractDE-AC52-07NA27344

LaboratoryresearcherscapturedsixR&D100awardsinR&D Magazine’sannualcompetitionforthetop100industrialinnovationsworldwide.Highlightsbeginningonp.4describetheaward-winningtechnologies:ahigh-performancestrontiumscintillatorforgamma-rayspectroscopy,asoftwareapplicationcalledthestatisticalradiationdetectionsystem,anx-rayfree-electronlaserenergymonitor,agrating-actuatedtransientopticalrecorder,ultrapermeablecarbonnanotubemembranes,andmicroelectromechanical-systems-basedadaptive-opticsopticalcoherencetomography.Since1978,Livermoreresearchershavereceived135R&D100awards.TheR&D100logoisreprintedinthisissuecourtesyofR&D Magazine.

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Lawrence Livermore National Laboratory

Contents

Departments

2 The Laboratory in the News

24 Patents and Awards

3 Shaping the Nation’s FutureCommentarybyThomasF.Gioconda

4 A Scintillating Radiation Detection MaterialAnewscintillatormaterialbeatsthecompetitionasthesuperiorgamma-raydetector.

6 Software Solution for Radioactive Contraband DetectionAninnovativesoftwaresolutionrapidlyandreliablydetectsradionuclideswhenmeasurementtimeisshortanddemandforconfidenceishigh.

8 Measuring Extremely Bright Pulses of LightAnewdetectorcannonintrusivelymeasureafree-electronlaser’sx-rayenergyinrealtime,pulsebypulse,andwithminimaleffectonthebeam.

10 High-Speed Imager for Fast, Transient Events at NIFAnovelinstrumentcanrecordthefleetingeventsduringthecreationoffusionignitionattheNationalIgnitionFacility.

12 Taking the Salt Out of the SeaCarbonnanotubemembranesimprovewaterdesalinationandreclamationprocessesforincreasingEarth’scleanwatersupply.

14 A Look inside the Living EyeOpticalcoherencetomographygetsaboostfromadaptiveopticsandmicroelectromechanicalsystemstoproduceunprecedentedimagesoftheretina.

16 Collaboration Expands the Periodic Table, One Element at a TimeA21-yearpartnershipwithaRussianinstitutehasaddedthesixheaviestelementstotheperiodictable.

20 Students and Researchers Partner for Summer ProjectsCompetitivesummerinternshipspairLivermoreresearcherswithstudentsforhands-oncareerexperience.

October/November 2010

Scientific editor

KerriJ.M.Blobaum

Managing editor

RayMarazzi

Publication editor

PamelaMacGregor

WriterS

GeriFreitas,RoseHansen,ArnieHeller,CarynMeissner,andKatieWalter

art director

AmyE.Henke

Proofreader

CarolinMiddleton

Print coordinator

CharlieM.Arteago,Jr.

S&TR,aDirector’sOfficepublication,isproducedbytheTechnicalInformationDepartmentunderthedirectionoftheOfficeofPlanningandSpecialStudies.

S&TRisavailableontheWebatstr.llnl.gov

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AvailablefromNationalTechnicalInformationServiceU.S.DepartmentofCommerce5285PortRoyalRoadSpringfield,Virginia22161

UCRL-TR-52000-10-10/11DistributionCategoryUC-99October/November2010

S&TR Staff 2010R&D100Awards

ResearchHighlights

TheLaboratoryintheNews

2 Lawrence Livermore National Laboratory

S&TR October/November 2010

cell(shownbelow),whichprobesthebehaviorofmaterialsunderultrahighpressures,theystaticallycompressedasampleofargonupto78,000atmospheresofpressure(where1atmosphereisthepressureatEarth’ssurface)andthenfurthershock-compresseditto280,000atmospheres.

Theteamanalyzedthepropagatingshockwavesusinganultrafastinterferometrictechnique.Combinationsofpressures,temperatures,andtimescaleswereachievedthatwerepreviouslyinaccessible.In

someexperiments,theresearchersobservedametastableargonstatethatmayhavebeensuperheated—astateofpressureandtemperatureatwhichargonnormallywouldbeliquidbutbecauseoftheultrashorttime

scaledoesnothaveenoughtimetomelt.“Thistechniqueforlaunching

andanalyzingnanoshockscanbeusedtostudyfundamentalphysicalandchemicalprocessesaswellas

improveourunderstandingofawiderangeofproblemsrangingfromdetonationphenomena

totheinteriorsofplanets,”saysLivermorephysicistJonathanCrowhurst.Resultsfromtheteam’s

researchappearedintheJuly15,2010,editionofJournal of Applied Physics.

Contact: Jonathan Crowhurst (925) 422-1945 ([email protected]).

VisualizingHowtoTurnPlantsintoBiofuelsAteamfromLawrenceLivermoreledbyMichaelThelen,in

collaborationwithresearchersfromLawrenceBerkeleyNationalLaboratoryandtheNationalRenewableEnergyLaboratory,hasusedfourdifferentimagingtechniquestosystematicallydrilldowndeepintothecellsofZinnia elegans,acommongardenannualplant.Theleavesofseedlingsprovidearichsourceofsinglecellsthataredarkgreenwithchloroplastsandcanbeculturedinliquidforseveraldaysatatime.Duringtheculturingprocess,thecellschangeinshapetoresembletubelikecellsthatcarrywaterfromrootstoleaves.Knownasxylem,thesecellsdevelopthebulkofplantcelluloseandlignin,whicharebothmajortargetsofrecentbiofuelresearch.

Usingvariousmicroscopymethods,theteamwasabletovisualizesinglecells,cellularsubstructures,fine-scaleorganizationofthecellwall,andevenchemicalcompositionofsinglezinniacells.Theresultsgobeyondwhathasbeenachievedforunderstandingthearchitectureofthespecializedcellwallthatcontainssuchanabundanceoflignocellulose.“Thebasicideaisthatcelluloseisapolymerofsugars,whichifreleasedbyenzymes,canbeconvertedintoalcoholsandotherchemicalsusedinalternativefuelproduction,”saysThelen.TheresearchappearedasthecoverarticleintheSeptember2010editionofPlant Physiology.Contact: Michael Thelen (925) 422-6547 ([email protected]).

MolecularMechanicsofaKeyProteinInapaperfeaturedonthecoveroftheJune16,2010,issue

ofBiophysical Journal,LivermorescientistsDanielBarskyandWillKuo,withcolleaguesfromtheUniversityofCaliforniaatSantaBarbara,CaliforniaInstituteofTechnology,andUniversityofCambridge,describethemolecularmechanicsofaproteinimportanttoallknowncomplexformsoflife.Theauthorsconductedmolecular-dynamicscalculationstorevealthemechanicsanddynamicsoftheeukaryoticslidingclampproliferatingcellnuclearantigen.

SlidingclampsaretoroidalproteinsthatencircleDNAandactasmobileplatformsforDNAreplicationandrepairmachinery.ThecalculationsreportedinthepaperareimportantforunderstandingthemechanicsofDNAreplication.Theworkalsoshowsthatlarge-scalemolecular-dynamicssimulations,whencombinedwithappropriatecoarse-grainedelasticmodelsofmolecularconformation,canrevealtheenergylandscapeoflargeconformationalchangesinproteins.Contact: I-Feng W. Kuo (925) 422-2251 ([email protected]).

ExperimentRevealsX-Ray–AtomInteractionsThefirstuserexperimentontheLinacCoherentLightSource

facility’sx-rayfree-electronlaser(XFEL)atSLACNationalAcceleratorLaboratorystudiedtheinteractionofshort-wavelengthpulseswithsingleatomsunderunprecedentedradiationconditionsofultrahighintensity.LawrenceLivermoreisoneofthecollaboratinginstitutions.Theresultsprovidethefirstexperimentalevidencefortheadvantageousradiationhardeningeffectusingultra-intensex-raypulses.

“Thebasicexperimentprobedourpreviouspurelytheoreticalunderstandingofhigh-intensityx-rayinteractionwithmatter,”saysNinaRohringer,aLivermorephysicistonthenationalteam.Aneontargetsequentiallyejectedelectronsduringthecourseof20-to100-femtosecond-durationx-raypulses(afemtosecondisone-quadrillionthofasecond).TheneontargetwascompletelystrippedduringtheinteractionwiththeXFELpulse,leavingabarenucleus.

“Oursuccessfulmodelingofx-ray–atominteractionsusingthisapproachhaspositiveimplicationsforproposedsingle-molecule-imagingexperiments,”saysRohringer.TheresearchappearedintheJuly1,2010,editionofNature.Contact: Nina Rohringer (925) 423-1806 ([email protected]).

MaterialBehaviorInsightIsaNanoshockLaboratoryphysicistsareusinganultrafastlaser-based

technique,dubbed“nanoshocks,”tostudyshockbehaviorintinysamplessuchasthinfilmsorothersystemswithmicroscopicdimensions(afewtensofmicrometers).Usingadiamondanvil

3Lawrence Livermore National Laboratory

n ThomasF.GiocondaisdeputydirectorofLawrenceLivermore NationalLaboratory.

CommentarybyThomasF.Gioconda

Shaping the Nation’s Future

generatedbyx-rayfree-electronlasers(XFELs).ThisinstrumentisinuseatSLACNationalAcceleratorLaboratory’sLinacCoherentLightSource,theworld’smostpowerfulXFEL.Thelightsourcecancaptureimagesofmoleculesandatomsinmotion,makingpossiblemanybreakthroughsinmaterialsscience,biology,andmedicine.

Inaddition,novelprize-winningtechnologiesaremeetingimportantnationalneedsforcleanwaterresourcesandimprovedhumanhealth.Laboratoryscientistsdevelopedafiltrationtechnologyconsistingofcarbonnanotubemembranesthatallowwatertoflowthroughabout1,000timesfasterthanconventionalmembranes.Thiscapabilitycouldprovideamorethan80-percentreductioninenergyconsumptionforbrackishwaterdesalination.Also,Livermoreandotherinstitutionsdevelopedanewclinicalinstrumentthatpermitsophthalmologiststoseetheeye’sretinaattheindividualcelllevel.Withthiscapability,doctorswillbeabletoobtainearlydiagnosesandtrackthetreatmentofretinaldiseases.

Theseawardsareatributetoourscientificandtechnicalexcellence,ourfocusonmission,andourworkforce’sdedicationtonationalservice.WithmycareerbackgroundasanofficerintheU.S.AirForceandaseniormanagerintheDepartmentofEnergy’sNationalNuclearSecurityAdministration,IgreatlyvalueservicetothenationandhavelongrecognizeditasavaluecentraltotheworkethicoftheLaboratory.ThismakesLivermoreaspecialplace.

ThemanyresearchersfeaturedinthearticlesdescribingtheR&D100awardsaretobecongratulatedfortheiroutstandingwork.Theirefforts—andthoseofeveryLaboratoryemployee—areshapingthenation’sfuture.That’swhywe’rehere.

OURresponsibilityasaforward-lookinglaboratoryistoshapethenation’sfuturethroughinnovative,multidisciplinary

science,technology,andengineering(ST&E).TheU.S.facesmanypressingchallengesinthe21stcenturythatcallfortheuniqueexpertiseandcapabilitiesofthenationallaboratories.LawrenceLivermoreisensuringthesafety,security,andeffectivenessoftheU.S.nuclearstockpileandpursuingprogramstopreventtheproliferationofnuclearweaponsandcounternuclearterrorism.Ouradvancesintechnologyareimprovingmilitarycapabilities,strengtheninghomelandsecurity,andsupportingtheintelligencecommunity.Inaddition,weareworkingtobetterunderstandclimatechangeanditsimpacts,provideforacarbon-emission-freeenergyfuture,andkeeptheU.S.attheforefrontofST&Eandcompetitiveintheinternationalmarketplace.

Thebreadthofourmissionresponsibilitiesandourinnovativeapplicationofcutting-edgeST&EareexemplifiedbytheLaboratory’sreceiptofsixR&D100awardsin2010—bringingourtotalto135suchawardssince1978.These“OscarsofInvention”arepresentedbyR&D Magazinetothetop100technologicaladvancesoftheyearthatcontributetomeetinganimportantnationalorsocietalneed.ThesixwinningtechnologiesdevelopedbyLivermoreandourmanyresearchpartnersaredescribedinthehighlightsbeginningonp.4.

NationalsecuritywillbeenhancedbytwoofourR&D100Awardwinners.Thestatisticalradiationdetectionsystem(SRaDS)isanovelsoftwaresolutiontorapidlyandaccuratelydistinguishnuclearmaterials,suchasplutoniumanduranium,fromotherradioactivesubstances.SRaDScaneasilybeintegratedintogamma-raydetectorsystemsusedforhomelandsecuritytosearchforcontrabandradioactivematerials.Asecondawardwaspresentedforthedevelopmentofanewmaterial—europium-dopedstrontiumiodide—thatwillenablehigh-resolutiongamma-rayspectroscopytobeperformedbyhandheldradiationdetectors,greatlyimprovingtheircapability.

TheNationalIgnitionFacility(NIF)atLivermoresupportsourstockpilestewardshipmission,offerstheprospectofdevelopingcarbon-emission-freefusionenergy,andprovidesremarkablecapabilitiesforscientificdiscoveryaboutouruniverse.AnR&D100Award–winningdiagnosticsystemforNIF,thegratingactuatedtransientopticalrecorder,willenableresearcherstoacquiresequentialimagesandmakea“movie”ofafusionignitionandburneventthatlastsonly50-trillionthsofasecond.

AnotherLivermore-developedscientificinstrumentalsoearnedanR&D100Award:asystemtomonitortheenergyofpulses


4

A Scintillating Radiation Detection Material

2010R&D100Awards

(a) A crystal of strontium iodide doped with

europium for gamma-ray detection is an R&D 100

Award winner. (b) The crystal is encapsulated when

used in a radiation detection device and

(c) glows blue when exposed to ultraviolet light.

Livermore development team for the strontium iodide scintillator: (from left)

Steve Payne, Nerine Cherepy, Owen Drury, Alex Drobshoff, Cheng Saw,

Ben Sturm, Thomas Hurst, Scott Fisher, and Peter Thelin.

(a) (b) (c)

ENSURINGthatthecountryremainssafefromanuclearorradiologicalattackisdrivingthesearchformoredefinitive

radiationdetectionandidentificationtechnologies.TheDepartmentofEnergyhasfordecadesbeenbuildingthescienceandengineeringbasisfordetectingillicitsourcesofplutoniumanduranium.Then,in2005,theDepartmentofHomelandSecurity(DHS)madeaboldrequesttodevelopsignificantlymoreeffectivematerialstodetectgammarays.Thesearchbeganinearnestfornewmaterialsforsmaller,faster,andmoreaccuratesensorsthatwouldimprovethenation’sabilitytounambiguouslyidentifyradiationfromillicitsources.

LawrenceLivermoreandOakRidgenationallaboratories,FiskUniversity,andRadiationMonitoringDevices,Inc.,inWatertown,Massachusetts,joinedforceswithDHStodevelopandoptimizenewdetectormaterials.Livermore’sStevePayneandNerineCherepyareleadingthecollaboration.“Afteralengthyprocessofscouringtheliteratureandsynthesizingandevaluatingpotentialmaterials,wedeterminedstrontiumiodidedopedwitheuropiumtobeawinner,”saysCherepy.TheteamhasreceivedanR&D100Awardfortheirwork.

ImprovingontheCompetitionDetectorsmadeofhigh-puritygermanium,asemiconductor,

havelongofferedthebestenergyresolution,allowingpreciseidentificationofthegammaraysemittedbyplutoniumanduranium.However,detectorsbasedongermaniumrequirespecialcooling,makingthemcostlyandheavytouse.Forfielduse,radiationdetectorsmustbeinexpensiveandrobust,operateatambient



5

radioactivity,orhavingtoolowanatomicnumbertoexhibitreasonablegammaabsorptionefficiency.Fromtheliterature,theteamassembledalistofprospectivematerials.Theythensynthesizedsmallsamplesofthecandidatesandevaluatedthescintillationproperties,eliminatingmany.Finally,theteamcreatedashortlistofabouttwodozencandidatesandthoroughlyinvestigatedtheproperties,ultimatelyidentifyingstrontiumiodidedopedwitheuropium,SrI2(Eu),asthematerialhavingoverallthemostusefulsetofproperties.

SrI2(Eu)canbeeasilygrown,resistscracking,andhasnoradioactiveconstituents.Thematerialalsoexhibitsaphenomenonknownasbetterlight-yieldproportionality.“Itturnsout,”saysPayne,“thatthefundamentallimittoscintillatorresolutionisdictatedbynonproportionality.”Proportionalityisadirectmeasureofhowmuchthelightyield(dividedbyelectronenergy)variesasafunctionoftheelectronenergy.Ifascintillatorwereperfectlyproportional,therelativelightyieldwouldbeahorizontallineat1forallelectronenergies.Nomaterialisperfectlyproportional;however,theclosertherelationshipistoahorizontalline,thebetteritsperformance.Comparedtoexistingcommercialmaterials,SrI2(Eu)hewsmostcloselytothishorizontalline.

PuttingtheWinnertoUseThepackagedSrI2(Eu)scintillatorcanbeeasilyincorporatedinto

thehandheldradiationdetectorsbeingproducedbymanycompaniesandwouldenhanceperformanceconsiderably.TheLaboratory’sIndustrialPartnershipsOfficeisinnegotiationswithseveraldetectorsuppliersasareplacementforNaI(Tl).

TheSrI2(Eu)scintillatorcanpotentiallyserveawiderangeofapplicationsthatusegamma-rayspectroscopytoidentifyradioisotopes.Isotopeidentifiersareacommontoolforprofessionalsinmedicine,policeandfireservices,andminingoperations.

Lastyear,DHSordered20scintillators,similartothecrystalshownonp.4,foruseinexperimentalhomelandsecuritydetection

devices.SaysCherepy,“Withitspoorerenergyresolution,thallium-activatedsodiumiodidecannotpickoutthespecificgammaraysofplutoniumanduraniumnearlyaswellasouraward-winningmaterial.Strontiumiodidedopedwitheuropiumoffersthebestscintillatoroptionyetfordetectionofpotentiallydevastatingradiologicalmaterials.”

—Katie Walter Key Words:gamma-rayspectroscopy,R&D100Award,radiationdetection,radiologicalattack,strontiumiodidescintillator.

For further information contact Nerine Cherepy

(925) 424-3492 ([email protected]).

Strontium Iodide Scintillator

temperature,providehighdetectionefficiency,andbesmallenoughforcovertoperations.

Aneffectivedetectormustalsoprovideunambiguousidentificationofamaterial.Suchdiscriminationisneededbecauseonlysomegamma-rayenergiesareindicativeofaradiationsourcethatposesathreat.Adetectormustalsopickupveryweaksignals,suchasthosefromplutoniumheavilyshieldedwithlead.Currentdetectortechnologyislimitedinitsabilitytomeettheserequirements.

Analternativetosemiconductorsisscintillators,inwhichradiationinteractswithamaterialtoproduceabriefbutmeasurableflashoflight.TheLivermore-ledteamhuntedforamaterialthatwouldproducethebrightestflashoflightwhenexposedtoplutoniumorhighlyenricheduranium.Theprecisionofthescintillatormaterial’sresponse,orenergyresolution,definesthematerial’sabilitytodistinguishbetweengammaraysthathavesimilarenergies.

Themostprominentscintillatormaterialinusetodayisthallium-activatedsodiumiodide,NaI(Tl),becauseitiseasytogrowinlargesizesandisthereforeinexpensive.However,itsenergyresolutionispoorcomparedtosemiconductors.Lanthanumbromidedopedwithceriumoffersthehighestenergyresolutionamongcommercialscintillators,butitisdifficultandcostlytogrowandisinherentlyradioactivebecauseofthepresenceoflanthanum-138.

StartfromSquareOne“DHSrecognizedthepotentiallytransformationalimpactthat

betterdetectormaterialscouldhaveonourradiationdetectioncapabilities,”saysPayne.“Sothecollaborationessentiallystartedbytakingoutacleansheetofpaperandasking,‘Whatispossible?’”

Theycrossedoffelementsontheperiodictablethatwerenotusablebecauseofsuchpropertiesasopticalabsorption,



6

Software Solution for Radioactive Contraband Detection

2010R&D100Awards


Development team for SRaDS: (from left) Brian Guidry, Kenneth Sale,

Michael Axelrod, Thomas Gosnell, James Candy, Sean Walston, David

Chambers, Eric Breitfeller. (Not shown: Dennis Slaughter, Jerome

Verbeke, and Stanley Prussin [UCB].)

fromLivermore’sLaboratoryDirectedResearchandDevelopmentProgram,“theteamcross-fertilizedtheareasofstatisticalsignalprocessingwithradiationtransportphysics,enablingauniqueandbreakthroughsolutiontoalong-troublingproblem,especiallyintoday’sclimateofterroristthreats.”

EACHyear,some48millioncargocontainersmoveamongtheworld’stransportationportalswithmorethan16million

containersarrivingintheU.S.byship,truck,andrail.Illicitradioactivematerialscouldbehiddeninanyoneofthesecargo-filledcontainers.Yet,physicallysearchingeverycontainerwouldbringshippingtoahalt.ImprovingsecurityatU.S.transportationportalsisthusoneofthenation’smostdifficulttechnicalandpracticalchallengesbecausethesystemsdevelopedforscreeningcargomustoperateinrealtimewithoutdisruptinglegitimatecommercialshippingactivities.

Workingatthisintersectionofcommerceandnationalsecurity,ateamofLivermorescientistsandengineersledbyprincipalinvestigatorJamesCandyapplieditsexpertiseinradiationscienceandgammadetectiontodevelopthestatisticalradiationdetectionsystem(SRaDS),aninnovativesoftwaresolutionthatnonexpertscanusetorapidlyandreliablydetectradionuclides.Theteam,alongwithICx®Technologies,Inc.,inArlington,Virginia,haswonanR&D100Awardforthetechnology.AccordingtoCandy,whoderivedearlysupport

The statistical radiation detection system (SRaDS) is an innovative software solution that can easily be

integrated into any gamma-detection system to combat illicit trafficking of radioactive material through

customs, border crossings, and limited-access areas. SRaDS identifies radionuclides in low-count situations

when measurement time is short and demand for reliability is high. The processed data are displayed in

intuitive plots showing results that a nontechnical user can interpret. (Rendering by Kwei-Yu Chu.)


7

Statistical Radiation Detection System

Software Solution for Radioactive Contraband Detection


techniques,SRaDSprovideshighlydevelopedquantitativestatisticalanalysisofthedatareceivedinrealtime.

What’smore,basicandadvancedprocessoroptionsareavailablewithSRaDS.Bothprocessoroptionsprovidecompletestatisticalanalysisofradionuclidedataobtainedfromanytypeofgammadetector.Thebasicandadvancedprocessorsgatherinformationfromunscatteredphotonsthatdepositfullphotonenergy.TheadvancedprocessoralsogathersinformationfromCompton-scatteredphotonsthatexhibitdiminishedenergy—amajorbreakthroughintime-domainlow-countdetectiontechnology.

IntegratesintoAnyGamma-DetectorSystemTheLivermoreteamtookspecialcaretoensurethat

SRaDScaneasilybeintegratedintoanygamma-detectionsystem,includinglargestationarydetectorsattransportationportalsthathelpsearchforcontrabandradioactivematerialinmovingvehicles,cargocontainers,andrailroadcars.SRaDSworksequallywellinpedestrianmonitorsusedtocombatillicittraffickingofradioactivematerialthroughcustoms,bordercrossings,andlimited-accessareas.Thetechnologycanalsobeinstalledinportablegammadetectorsusedbyfirstresponderstodetermineradiationrisksassociatedwithlocalnuclearemergencies.Thealgorithmsareeasilyembeddedinprogrammablegatearraysthatuserscanadjustinthefieldtoalocation’sspecificationsanddetectionrequirements.

Dependingonthehardwaresetup,theprocesseddatacanbegraphicallydisplayedonacomputermonitororportableunit.Whileconventionalgamma-detectionsystemsrequireahighlytrainedpractitionertoanalyzetheresults,refinethedata,andguidetheinterpretationprocedure,SRaDSdisplaysdatainintuitiveplotsshowingresultsthatanontechnicalusercaninterpret.Alternatively,SRaDScanbeconfiguredtosimplyprovideaudioandvisualalertsindicatingthepresenceoftargetedradionuclidesatuser-selectedconfidencelevels.Userscanalsoselectfalse-alarmprobabilitiestoreduceoreliminatetheoccurrenceoffalsepositivesdependingonthelevelofdetectionrequiredforagivensituation.

Theresultisacomprehensivesoftwaresystemthatcombinesoutstandingradionuclide-detectionperformancewithhighreliabilityandashortacquisitiontime.SRaDScaneasilybeimplementedinexistinginfrastructuretoprotectthenationfromtheinsidiousthreatofillicitradioactivematerials. —Geri Freitas

Key Words:Bayesianprocessingtechniques,cargocontainer,gammadetector,R&D100Award,radionuclidedetection,statisticalradiationdetectionsystem(SRaDS).

For further information contact James Candy (925) 422-8675

([email protected]).

RapidandReliableRadionuclideDetectionIdentifyingradioactivematerialinamovingtargetisadifficult

problemprimarilybecauseoftheverylowcountsofgamma-raysignalsduringtheshorttimeintervalfordetection.Inlow-countsituationssuchasthese,conventionalspectrometrytechniquesdonothaveenoughtimetocollectthenumberofprotonsrequiredtocalculatethepulse-heightspectrathatidentifyradioactivematerials.Forexample,avehiclemovingthroughagamma-detectionsystematatransportationportalisscreenedforlessthan10seconds.Accurateradionuclidedetectionisevenmoredifficultwhenradioactivematerialisshieldedbylead,packaging,oradjacentcargo.

SRaDSspeedsupidentificationbyautomaticallyrejectingextraneousandnontargetedphotonsduringtheprocess.ExploitingBayesianalgorithms,thesmartprocessorexamineseachphoton—onebyone—asitarrivesandthen“decides”whetheradetectedradionuclideispresentbasedonselectedparameters.Thiscapabilityisnotavailableinconventionaldetectionsystems,yetitisessentialinthesuccessfulidentificationofradionuclidesinlow-countsituationswhenmeasurementtimeisshortanddemandforreliabilityishigh.

WhenacargocontainerarrivesatanSRaDSdetector,adecisionfunctioninthesoftwareisrefreshed,updated,andrefinedbasedontheenergiesandarrivaltimesoftheacceptedphotons.Detectionisdeclaredonlywhenstatisticallyjustifiedaccordingtothreefactors—theBayesianalgorithms,theupdateddecisionfunction,andtheconditionsdefinedbythespecificreceiver-operatingcharacteristiccurveobtainedduringinitialcalibration.Incontrast,conventionaltechniquesrequiremanuallysettingaspecificcountingtimeinadvancewiththehopethatthedataacquiredcanjustifythedecision.ByencompassingthestatisticalnatureofradiationtransportphysicsandsequentialBayesianprocessing

8

2010R&D100Awards

Energy monitor development team: (from left) Donn

McMahon, Mark McKernan, Richard Kemptner, Dmitri

Ryutov, Richard Bionta, Daniel Behne, Keith Kishiyama,

Stefan Hau-Riege, Vasco daCosta, Marty Roeben,

and Robert Geer. (Not shown: Elden Ables, Stewart Shen

[now retired], Alan Wootton [formerly of Livermore], Jacek

Krzywinski [SLAC], and Marc Messerschmidt [SLAC]).



Measuring Extremely Bright Pulses of Lightto8kiloelectronvolts,andthephotoluminescence-basedpulse-energydetectorprovidedtherequiredcalibrationinformationfortheteamtostudytheinteraction.Nitrogengaswaschosenfortheexperimentsbecauseitisnonhazardousanditsultravioletluminescencebehavioriswellunderstoodfromuseinpreviousstudiestodetectandcharacterizecosmicrays.

X-RAYfree-electronlasers(XFELs)aretunable,high-powersourcesofshortphotonpulses.Thesenewmachinesoffer

significantpromiseforscientificandmedicalbreakthroughsbycapturingthemotionofmoleculesandevenatoms.TheintensepulsesgeneratedbyXFELsarebeginningtoenhancetime-resolvedresearchinbiology,chemistry,materialsscience,andphysics.Designingdiagnosticinstrumentsforxraysischallenging,particularlyforhigh-energypulses,becausethex-raybeamcandamagetheequipment.

IncollaborationwithSLACNationalAcceleratorLaboratoryinStanford,California,LawrenceLivermorescientistswonanR&D100Awardfordevelopingadetector,calledtheXFELenergymonitor,thatmeasuresthispulse-by-pulseenergyinrealtimewithoutbeingdamagedbythebeamandwithminimaleffectonbeamquality.Theteamprobednitrogengasatx-rayenergiesup

(left) At the Linac Coherent Light Source facility, new energy monitors

installed on the x-ray free-electron laser nonintrusively measure photon

beam energy. (right) The x-ray energy monitor is part of the photon

diagnostic and conditioning suite.

9

XFEL Energy MonitorS&TR October/November 2010


ThreeXFELenergymonitorsarecurrentlyinuseatSLAC’sLinacCoherentLightSourcefacility.InoperationsinceApril2009,thislightsourceistheworld’sfirsthardXFEL,capableofgeneratingxrayswithwavelengthscomparabletoatomicdistances.ItisalsothefirstXFELavailableforscientificresearch,providinguserswithvirtuallyinstantaneouspulse-energydata.Duringthenextfewyears,XFELfacilitiesinJapan,Germany,Italy,Switzerland,andEnglandarescheduledtocomeonline.

RevealingtheUnseenXraysareusefulforexaminingallkindsofmatter,fromDNA,

bones,andlungstothematerialscomprisingstars.Ifxraysaresufficientlyintenseandproducedinultrashortpulses,theycanrevealinformationaboutdynamicprocessesinmanystatesofmatter,suchassolid,liquidcrystal,andextremelydenseplasma.Thesepulsesaremuchlikeflashesfromahigh-speedstrobelight,enablingscientiststotakestop-motionpicturesofatomsandmolecules.XFELpulsesallowresearcherstomeasureextremelyfastphysicaleventswithatomicresolution.Thetechnologycanbeappliedtostudyregimesforthefirsttimeinavastrangeoffieldsincludingultrahigh-energy-densityphysics,structuralbiology,fundamentalquantumelectrodynamics,warmdensematter,andatomicphysics.

AnXFEL’sbeampulselastslessthan100femtoseconds(afemtosecondisone-quadrillionthofasecond),anditsbeamwavelengthmeasuresjustabout0.1nanometers(aboutthediameterofthesmallestatom).Thelaser’speakbrightness—uptoafewgigawatts—isbillionsoftimeslargerthanthatgeneratedbysynchrotrons,formerlythebrightestlightsources.“TherevolutionaryoutputcharacteristicsofanXFELpropelsusinto

acompletelynewregimeofx-ray–matterinteraction,”saysLivermorephysicistStefanHau-Riege,whoheadedthedetectordevelopmentteam.

InstrumentIsNotIntrusiveAccordingtoHau-Riege,studyinghowmatterinteracts

withxraysrequirescontinuous,detailedcharacterizationoftheultrahigh-intensityphotonbeam,withminimalintrusion.Knowledgeofbeamparameterssuchasphotonflux(thenumberofphotonsarrivingatapoint)isessentialbecausetheparametersdeterminehowthebeaminteractswiththeexperimentalsample.However,ascertainingXFELbeamcharacteristicsisparticularlychallengingbecausethebeamcaneasilysaturateorevendestroycommonlyusedsolid-statedetectors.TheXFELenergymonitor,whichbarelydisturbstheintensityofthex-raybeam,preservesbeamcoherenceandcanbeoperatedinaregimeinwhichtheattenuationislessthan1percent.

Thetotalpulseenergyisinferredfromultravioletradiationgeneratedbythenitrogengascontainedinthevesselthroughwhichthebeamtravels.Whenthebeamtraversesthevessel,thenitrogenisexcitedandemitsfluorescentradiationthatisdetectedbytheenergymonitor’sphoton-multipliertubes.Thenitrogengasiscontinuouslyreplenishedandmaintainedataconstantpressurebyaseriesofpumps.Hau-Riegesaystheinteractionofhardx-rayphotonswithnitrogenissmall,andifnecessary,thenitrogengasdensitycanbedecreasedduringoperation.

ABrightFutureAlthoughtheenergymonitorwasdevelopedprimarilyfor

characterizingultrahigh-brightnessx-raypulsesfromhardXFELfacilities,itmayalsobeusedtocharacterizelessbrightx-raysources.Infact,theteamsuccessfullytestedaprototypeofthedeviceattheStanfordSynchrotronRadiationLightSource,whichgeneratesx-raybeamswithintensitiesbillionsoftimesweakerthantheLinacCoherentLightSource.

AresearchpaperdescribingtheXFELenergymonitorappearedintheJuly23,2010,editionofPhysical Review Letters.Thepaperwasco-authoredbytheLivermoreresearchers,togetherwithcolleaguesfromSLACandtheCenterforFree-ElectronLaserScienceinHamburg,Germany.Thepaperhashelpedtocommunicatetothephysicscommunitythatthemostenergeticx-raybeamseverproducedcanbewellcharacterized. —Arnie Heller

Key Words: LinacCoherentLightSource,R&D100Award,SLACNationalAcceleratorLaboratory,x-rayfree-electronlaser(XFEL)energymonitor.

For further information contact Stefan Hau-Riege (925) 422-5892




FUSIONignitionexperimentsattheNationalIgnitionFacility(NIF),theonlylaboratoryintheworldcapableofre-creating

theextremetemperaturesandpressuresfoundinstarsandinthermonuclearweapons,willlastonlyafewbillionthsofasecond.Anactualfusion“event,”whenacapsulefilledwithtritiumanddeuterium—isotopesofhydrogen—undergoesignitionandthermonuclearburn,occursinjusttrillionthsofasecond,muchtooquicklyfortraditionaldiagnosticandimagingequipmenttorecord.

FortheNationalIgnitionCampaigntoreachitsgoalsofadvancingunderstandingofplasmaphysicsandhelpingtocertifythereliabilityandsafetyofthenation’sagingnuclearstockpile,anewgenerationofultrafast,high-resolutiondiagnosticequipmentmustrecordeventsinpicoseconds(trillionthsofasecond).Tomeetthatneed,Livermorephysicistsdevelopedthegrating-actuatedtransientopticalrecorder(GATOR),whichwonanR&D100Award.Thisopticalinstrumentisdesignedtocaptureandrecordfleeting,sequentialimagesofxraysandotherradiationemittedfromtheminiature“stars”createdintheNIFtargetchamber.

ANewConcepttoRecordIgnitionAnentirelynewconceptforhigh-speedimaging,GATOR

encodestwo-dimensionalx-rayoropticalimagesontocoherent

2010R&D100Awards

High-Speed Imager for Fast, Transient Events at NIF

The grating-actuated transient optical recorder (GATOR) is designed

to acquire sequential images of x rays or optical light in a trillionth of a

second or faster during experiments on the National Ignition Facility.

light.Itsdesignisderivedfroma2009LaboratoryDirectedResearchandDevelopmentprojectonprobingextremehigh-energy-densitystatesofmatterwithxrays.Theinstrumentcanprovidethenecessarytimeresolutioninpicosecondstorecordx-rayoropticalimagesofNIF’signitionevents,enablingscientiststobetterunderstandthephysicalprocessesoccurringintheseexperiments.Becausetheradiationconversionprocessisdoneoptically,GATORdoesnotusechargedparticlesandthusdoesnotsufferfromthefundamentalspace-chargelimitationsofcommercialelectro-opticalsystems,whichcanrestrictasystem’sspeed,spatialresolution,anddynamicrange.

Inaddition,becauseGATORcanconvertxraysandothertypesofradiationtocoherentopticalradiation,whichcanbetransportedandrecordedremotely,theinstrumentcanoperateinanenvironment


11

ignitionevent)strikesagratingormaskcontainingaseriesofthinbarsthatblocksomeofthelight.Thispatternoflightisthenfocusedonaspeciallytreatedsemiconductor,whereitisabsorbed.Theabsorbedlightmodifiestheopticalpropertiesofthesemiconductorinproportiontotheintensityoftheillumination.Aprobelaserbeamstrikingtherearsurfaceandreflectingoffthefrontsurfaceofthesemiconductorpassesthroughtheopticallymodifiedsemiconductortwice,diffractingaportionofthebeamawayfromitsoriginalpath.Thefocusedpatternofthediffractedbeamisaseriesofspots,oneforeachdiffractionangle,arrayedsymmetricallyaroundtheundiffractedpartoftheprobebeam.Thediffractedportionofthebeamisrelayedbyalenssystemandfocusedtoformhigh-resolutionimagesoftheincidentradiationonacharge-coupled-devicedetectorlocatedatadistanceandheavilyshieldedfromtheexperiment’shigh-energybackgroundradiation.

Becausethedurationoftherecordingisdeterminedbythedurationoftheappliedlaserbeam,GATORcanacquiresequentialimages,capturingtemporalchangesinthetargetinasmall“movie”ofthefleetingevent.Theinstrumentconvertsthesourceradiationtoopticalimagesbeforeslower-movingneutrons,chargedparticles,ordebriscanreachthesemiconductor.BecauseGATORisanall-opticaldevice,noelectronicsorcablesneedtobelocatednearthex-raysource,helpingmakethesystemmuchlessvulnerabletothepotentiallydestructiveeffectsofradiationandelectromagnetic-pulsefields.Livermorecalculationsshowthattheinstrumentcan

produceusefulimagesinenvironmentswithneutronyieldsgreaterthan20megajoules.

Aflexiblesystem,GATORcanbeadoptedforanyapplicationinwhichveryfast,high-powerenergysourcesareusedorcreated,including

high-powerlasers,free-electronx-raylasers,andhigh-energy-densityobjects.GATORwillallowdetailedmeasurementstobetakenoftheignitionconditionsinvolvedinstudyingthehigh-energy-densityphysicsofthermonuclearburn,advancingscientificunderstandingofstarsandfurtheringstockpilestewardship.

—Arnie Heller

Key Words:electromagneticpulse,fusion,grating-actuatedtransientopticalrecorder(GATOR),NationalIgnitionCampaign,NationalIgnitionFacility(NIF),R&D100Award.

For further information contact Warren Hsing

(925) 423-2849 ([email protected]).

Grating-Actuated Transient Optical Recorder

inwhichcopiousamountsofneutrons,xrays,andgammaraysarereleasedduringignitionexperiments.Theseradiationlevelswouldalmostcertainlydisableordestroyconventionaldetectorsinstallednearanignitingcapsule.

CreatingIgnitionatNIFTheextremetemperaturesandpressuresoccurringduring

NIFignitionandburn—predictedbysimulationstolastforonly50-trillionthsofasecond—createenormouschallengesfordiagnosticinstruments.Duringthattime,conditionschangerapidly,withthecapsuleemittingxrays,gammarays,andneutrons.Two-dimensionalimageswithaspatialresolutionofaboutfive-thousandthsofamillimeterandatimeresolutionofaboutfive-trillionthsofasecondareneededtomeasurethedetailedphysicalprocesses.Theinstrumentmustachievethisperformancewithoutbeingaffectedbyhard-to-shieldneutronsandgammaraysortheelectromagneticpulsetheygenerate.TheGATORdiagnosticcanrecordasequenceofimageswithpicosecondtimeresolution,enablingresearcherstomeasurethesefasttransientphenomena.

TheGATORdiagnosticsystemhasfourelements:agrating,aspeciallypreparedsemiconductor,aprobelaser,andarecordingsystem.Radiationfromanexternalsource(inthiscase,the

The GATOR development team: (from left) Steve Vernon, Rick Stewart,

Warren Hsing, Mark Lowry, and Paul Steele. (Not shown: Susan Haynes.)


Lawrence Livermore National Laboratory12


processeshavehindereddevelopmentoflarge-scaledesalinationfacilitiesinthepast,CNTmembranescouldhelpmakesuchfacilitiesawidespreadreality.

MoleculesGowiththeFlowBillionsofcarbonnanotubes,eachoneabout50,000times

thinnerthanahumanhair,aregrownonasinglesiliconsubstrateusingchemicalvapordeposition.(SeeS&TR,January/February2007,pp.19–20.)Thespacebetweenthis“forest”ofnanotubesisthenfilledwithamatrixmaterialsuchassiliconnitridetocreatethemembrane.Excessmaterialisremovedfromeitherend,andthetopandbottomofthenanotubesarereopenedusingareactiveion-etchingprocess.

“TheprimaryadvantagetoCNTmembranesisthatwaterflowsthroughthematarate1,000timesfasterthanthroughthepolymer-basedmembranestypicallyusedinwaterfiltrationequipment,”saysformerLivermorescientistJasonHolt.ThisfasttransportismadepossiblebecauseoftheuniquepropertiesofaCNT’sinnersurface,whichisatomicallysmooth,hydrophobic,andnonpolarwithauniformdistributionofelectrons.Asaresult,watermolecules,whicharepolarinnature,bondtoeachotherinsteadoftotheCNTwalls,enablingthemtomovetogetherrapidlyinacontinuouschain.“Thisfrictionlessflow,”saysOlgicaBakajin,anotherformerLivermorescientistwhocoledthe

WATERisapreciousnaturalresourceandoneofthebasicbuildingblocksoflife.Yet,accordingtoUNICEF,nearlyonein

sixpeopleworldwidelacksaccesstocleandrinkingwater.Insomeareas,waterscarcityhasresultedinconflictbetweenneighboringstates.Asdemandforthisresourcecontinuestoincreaseglobally,findingwaystomakemoreofEarth’swater—97percentofwhichisseawater—fitforhumanconsumptionwillbeofgreatimportanceincreatinganadequatecleanwatersupplyforthebillionsofpeopleworldwide.

AnovelR&DAward–winningmembranetechnologydevelopedbyLawrenceLivermoreinpartnershipwithPorifera,Inc.,inHayward,California,andwithearlysupportfromLivermore’sLaboratoryDirectedResearchandDevelopmentProgram,couldleadtomorecost-effectivefiltrationprocessesforwaterdesalinationandreclamationthanareavailabletoday.Thehighlypermeable,chemicallyinertmembranesarecomposedofcarbonnanotubes(CNTs),whicharehollow,seamlesscylinders.ExtremelysmoothinteriorwallsallowliquidsandgasestorapidlyflowthroughCNTs,whilerejectinglargermolecules.

BecauseofaCNTmembrane’ssophisticatedstructureandmaterialproperties,solutessuchassaltandotherioniccompoundscanbefilteredoutofseawaterorbrackishwaterusingsubstantiallylessenergythanisneededtoachievesimilarresultswithconventionalpolymer-basedmembranes.Althoughthehighenergycostsandrelativelylowefficienciesofstandardwaterfiltration

2010R&D100Awards

Taking the Salt Out of the Sea

Inside an atomically smooth carbon nanotube, water molecules form

linear chains flowing at an ultrafast rate. Shown is an ion being rejected

by a carbon nanotube pore. Filtration membranes composed of carbon

nanotubes could make water desalination processes more efficient and

cost effective. (Rendering by Scott Dougherty.)


13

Ultrapermeable Carbon Nanotube Membranes

Incontrast,CNTmembraneshaveintrinsicallyhigherpermeabilitythanconventionalmembranes,sotheycanbemadethickerwithoutsacrificingflowrate.Thisthicker“skin”reducesthelikelihoodofpinholedefects,andthemembranes’overallcompositionmakesthemimmunetodeleteriouscompactioneffects.

VersatileMembranesLivermorelicensedthetechnologytoPorifera,Inc.,in2009,and

theproductisundergoingcommercialdevelopmentandtesting.Itspriceisexpectedtobeapproximately$20persquaremeter,whichiscomparabletothepriceofexistingpolymer-basedmembranes.AndCNTassembliescanbebuilttothespecificationsrequiredforreplacingmembranecartridgeswithinexistingequipment,eliminatingthepotentialforadditionalinfrastructurecoststosupportthetechnology.

AnotherbenefitofCNTmembranesisthattheycanbecustomizedforavarietyofapplications.AtLivermore,theyarebeingappliedtoseveralareasofresearch.“We’reusingthistechnologyaspartofanefforttodevelopbreathablefabricsforprotectiveclothing,”saysLivermorescientistFrancescoFornasiero.ThefasttransportcapabilitiesofCNTmembranesallowwatervaportoescapethroughthematerial,unlikemostprotectivefabricsthatkeepmoisturein.Peoplewearingthematerialcanstaycooler,longer.“Thesefabricswouldhelppreventheatstressinpeoplesuchassoldiersandfirefightersworkinginhazardous,high-temperatureenvironments,”hesays.

CNTmembranesarealsoplayingaroleinnationalsecurityandcarbonsequestrationresearch.“Theycouldpotentiallyovercomethelimitationsofgasseparationmembranetechnologiesaswellascurrentcarbondioxideseparation

processes,”saysSangilKim,alsoformerlyofLivermore.Ideally,CNTmembranescouldbeusedtoseparatecarbondioxidefromthefluegasgeneratedbyindustrialfacilitiessuchascoal-firedpowerplants.Fromhelpingto

increasetheworld’scleanwatersupplytoreducingcarbonemissions,CNTmembranesmaybecomeessentialtomanagingnaturalresourcesforfuturegenerations.

—Caryn Meissner Key Words:carbonnanotube(CNT)membrane,desalination,filtration,R&D100Award,reclamation,reverseosmosis.

For further information contact

Francesco Fornasiero (925) 422-0089


research,“couldresultinamorethan20-percentreductioninenergyconsumptionforseawaterdesalinationandamorethan80-percentreductionforbrackishwaterdesalination.”

NanotubesPerformWellunderPressureReverseosmosisisapopulartechniqueforliquiddesalination.

Inthisprocess,pressureisappliedtoasalinesolution,andtheliquidispushedthroughasemipermeablemembranethatblocksthepassageofsodiumchlorideorotherdissolvedsolids.Thus,thewaterthatpassesthroughtotheothersideofthemembraneispurified.Becauseofthelawsofthermodynamics,enoughpressuremustbeappliedtopreventthepurifiedwaterfrompassingbackthroughthemembraneintothesalinesolution.“Wemustovercomethedifferencebetweentheosmoticpressureoftheseawaterandthepurewatertoseparatethewaterfromthesalt,”saysformerLivermorescientistAleksandrNoy,whoalsocoledthedevelopmenteffort.

Polymer-basedmembranesarelesspermeablethanthosemadefromCNTsandthusneedmorepressuretoobtainthedesiredflowrate.Unfortunately,waterfiltrationequipmentconsumesmoreenergytoproducehigherpressures,whichsubstantiallyincreasesoperationalcosts.Toincreaseflowratewithoutincreasingoperationalpressure,manufacturersbuildconventionalmembranesasthinlyaspossible.However,thinnermembranesaremoresusceptibletodevelopingdefects,suchaspinholes,thatreducethemembrane’sefficiency.Inaddition,underpressure,themembraneporesconstrict,furtherreducingthealreadylimitedflow.

The carbon nanotube development team: (from

left) Francesco Fornasiero, Sangil Kim, Olgica

Bakajin, and Aleksandr Noy. (Not shown: Jason

Holt and Hyung Gyu Park.)


S&TR October/November 2010 2010R&D100Awards

Comparedwithotherdiagnostictoolsthatimagetheinternalstructureoftheeye,suchasfunduscamerasandscanninglaserophthalmoscopes,MEMS-AO-OCTistheonlyonethatcanprovide3Dimagesofmultiplelayerswithintheretina.Inaddition,itsautomatedcomponentsenablethetesttoberunbyatechnicianratherthanaphysician,reducingaprocedure’soverallcost.

ObtainingaClearViewMEMS-AO-OCTincorporatesanAOsystemsimilartotheone

pioneeredatLivermore,withinitialsupportfromtheLaboratoryDirectedResearchandDevelopmentProgram,foruseinlarge,high-poweredtelescopes,suchasthoseatW.M.KeckObservatoryonthebigislandofHawaii.Inthiscapacity,AOsystemscorrectwavefrontaberrationscausedbyatmosphericdistortion,whichblurourviewfromEarthofstars,galaxies,andothercelestialobjects.ThesameprincipleisappliedtoMEMS-AO-OCT,exceptthattheopticscorrectandcompensateforaberrationsfromocularconditionssuchasmyopia(nearsightedness),hyperopia(farsightedness),andastigmatism(irregularcurvatureofthelens).Theseconditionsdistortthelightcomingintotheeye,causingblurredvisionandalsolimitingtheimageresolutionofretinalscans.

OCTsystemsarebasedoninterferometry,wherelightfromasinglesourceissplitintoasampleandareferencebeam.

OPHTHALMOLOGISTSandoptometristshaveasuiteoftoolsfordiagnosingandtreatingeyedisease.Opticalcoherence

tomography(OCT),forexample,enablesphysicianstolookdeepinsidetheeyetoimagethesubsurfacetissuestructurewithintheretina—thelight-processingcomponentofthevisualsystem.Amoreadvancedversionofthistechnologyhasthepotentialtohelpphysiciansimagetheeyeatthecellularlevel,allowingthemtodetectandmonitoroculardiseaseatitsearlieststages.

FundedbytheNationalEyeInstitute,Livermorescientistsandengineers,incollaborationwiththeUniversityofCaliforniaatDavis,IndianaUniversity,andBostonMicromachinesCorporationinCambridge,Massachusetts,havecreatedanOCTsystemthatincorporatesmicroelectromechanicalsystems(MEMS)andadaptiveoptics(AO)tononinvasivelyobserveandrecordultrahigh-resolution,three-dimensional(3D)retinalimagesinrealtime.“Usingthisinstrument,physicianscanseethelayerswithinalivingeyeingreaterdetailthaneverbefore,”saysDianaChen,aLivermoreengineerwhoisoneoftheleadscientistsontheteam.CalledMEMS-AO-OCT,thisdeviceallowspreciseinvivovisualizationandcharacterizationofallthecellularlayersinthehumanretina.Italsoprovidesapermanent,digitizedrecordofclinicalobservationsformonitoringdiseaseprogressionandtheeffectivenessoftherapeutictreatments.Thisyear,theteamreceivedanR&D100Awardforthebreakthroughtechnology.

A Look inside the Living Eye

Microelectromechanical-systems-based adaptive-optics optical coherence

tomography (MEMS-AO-OCT) provides a three-dimensional image of

the cellular layers within the retina. (inset) An image of the photoreceptor

layers within the eye allows physicians to diagnose sight-threatening

diseases, such as macular degeneration, in their earliest stages.

15

MEMS-Based Adaptive-Optics Optical Coherence TomographyS&TR October/November 2010

movedwithinaphysician’soffice.Inaddition,itscommercialcomponentsmakethesystemafinanciallyfeasibleoptionforpractices,anditscostiscompetitivewithexistinginstrumentsthathavemuchlowerresolution.

It’sAllintheDetailsMEMS-AO-OCTtechnologycouldbeadaptedforuseinother

medicalfields.Becausebiologicaltissuesabsorbandreflectlightdifferently,theintensityandwavelengthofthelightsourcemustbegaugedtospecifictissuestooptimizeimageresolution.MEMS-AO-OCTcanbeeasilyadjustedtoaccommodatethesevaryinglightparameters,makingitavaluabletoolfordiagnosingandtreatingmanyhealthconditions,includingcardiovasculardisease.Inaddition,dentistscouldimagebothhard(teeth)andsoft(gums)tissues,andoncologistscouldidentifycancercellswellbeforetheydevelopintotumors.“Thesystemcouldultimatelyhelpmedicalprofessionalsaccuratelydiagnosediseases,dramaticallyreducingthecostofmedicaltreatmentandimprovingthequalityoflifeformillionsofpeople,”saysChen.

Today,MEMS-AO-OCTisprovingitscapabilitiesasastate-of-the-artretinalimagingsystem.Livermore’sacademicpartners,theUniversityofCaliforniaatDavisandIndianaUniversity,havebuiltandcurrentlyoperateMEMS-AO-OCTaspartofclinicaltrials.Morethan100patientswithhealthyanddiseasedeyeshavebeentestedwiththesystemthusfar.Resultshavebeenpromising,illustratingthesystem’sabilitytoimageminutechangesintheretinathatwouldnothavebeendetectedwithstandardimagingtechniques.“Withoutadaptive

optics,theresolutionofaclinicalOCTsystemisinsufficientforimagingindividualcellularstructure,”saysChen.“ByincorporatingadaptiveopticsandMEMS-basedsystemsintoOCT,we’vedevelopedaclinicalinstrumentthatisreliable,affordable,and

farmoreeffectivethananythingelseonthemarket.”

—Caryn Meissner

Key Words:adaptiveoptics(AO),deformablemirror,microelectromechanicalsystems(MEMS),oculardisease,opticalcoherencetomography(OCT),R&D100Award,retinalimaging.

For further information contact

Diana Chen (925) 423-5664


Thesetwoseparatebeamstravelalongdifferentpathsuntiltheyultimatelyreuniteinadetectorthatmeasurestheirinterference.InMEMS-AO-OCT,anultrabroadbandlightisgeneratedusingasuperluminescentdiode,andthesamplebeampropagatesthroughaseriesoftelescopes,mirrors,andhorizontalandverticalscannersbeforereachingthepatient’seye.Thelightbeamisfocusedontothepatient’sretinainaraster,oruniform,pattern,creatingindividual“snapshots”ofeachlayer.Awavefrontsensorautomaticallymeasuresthepatient’sopticalaberrations.AMEMSdeformablemirrorworkinginconjunctionwithaBadaloptometerandapairofrotatingcylindersthencompensatesforthesedistortions.“Thesecomponentsenablethedevicetobeeffectiveevenforpatientswhohavelargerefractiveerrors,obviatingtheneedtofitpatientswithtriallenses,”saysChen.Thelightreflectedofftheretinaisthenrelayedbackthroughthesystemtothedetector.Thereferencebeam,whosepathlengthmatchesthatofthesamplebeam,reflectsoffapairofmirrorsintothedetector.

Compactafocaltelescopesalignthesystemcomponentswiththepatient’spupiltoachieveprecisemeasurements.Insidethedetector,aspectrometerandacharge-coupled-devicecamerarecordthesampleandreferencesignatures.Customcomputersoftwareinterpretstherecordedsignalsandproduceshigh-resolution,3D,digitalimages.Thedevicehasatotalfootprintofapproximately0.5cubicmetersandcanbeeasilyplacedand

Livermore development team for MEMS-

AO-OCT: (from left) Diana Chen, Scot

Olivier, and Steven Jones.

THELaboratory’scollaborationwiththeJointInstituteforNuclearResearch(JINR)inDubna,Russia,beganin1989when

Livermore’sKenHuletandProfessorGeorgyFlerovofJINRmetataconferenceandagreedtoworktogethertocreatesuperheavyelements.Researchershaveahistoryofoftenoverlookingnational

Collaboration Expands the Periodic Table, One Element at a Time

S&TR October/November 2010 ResearchHighlights

Lawrence Livermore National Laboratory16

boundariesandinternecinesquabblesintheinterestofadvancingscience.Butthispartnershipwasparticularlyremarkablebecause,saysLivermore’sKenMoody,“thesuperheavyelementcommunitythenwasincrediblycompetitive.”Together,thispartnershiphasaddedthelasthalfoflineseventotheperiodictable,creating

Thehighestatomic-numberelements,beginningwithneptuniumandplutonium(elements93and94),haveallbeencreatedinthelaboratory.Sincethediscoveryofplutonium,scientistshavefabricated24moreelements,eachonehighlyradioactiveaswellasheavierand,forthemostpart,withashorterhalf-lifethantheonebeforeit.Atomscanhavemultipleisotopes,dependingonthenumberofneutronsintheatom.Element114,forexample,hasanisotopecalled114-289,whichcontains289nucleonsinthenucleus(114protonsand175neutrons).Superheavyelementsarethosewithaveryhighnumberofprotons,beginningwithelement104(rutherfordium).MoodydidhisgraduateworkonsuperheavyelementsattheUniversityofCaliforniaatBerkeleyunderProfessorGlennT.Seaborg(1912–1999),oneofthegreatdiscoverersofheavyelements.Element106,seaborgium,isnamedforhim.

Inthe1960s,afewphysicistspredictedthatsomesuperheavyelementswouldsurvivelongerthananyoftheirsynthesizedpredecessors—aso-called“islandofstability”inaseaofexceedinglyshort-livedelements.Theveryearliestestimatesforthehalf-livesofthesemorestableelementswereashighasbillionsofyears.Later,computermodelinghugelyreducedthe

elements113to118.Thelatestelement,117,wasaddedinearly2010.Muchofthisresearchhasbeensupported,inpart,byLivermore’sLaboratoryDirectedResearchandDevelopmentProgram,beginningwithaprojectin1995toexaminenuclearstabilityinheavynuclei.

NuclearchemistsRonLougheedandMoodywerethefirstAmericanstoperformexperimentsinDubna,spendingamonthatJINRin1990.Itiseasytodaytoforgethowdifferenttimeswerein1990.BoththeU.S.andtheSovietUnionwerestilltestingnuclearweapons.TheBerlinWallhadfallen,andalthoughtheSovietUnionwaswobbling,itremainedintact.SomeSovietstateswerebeginningtoflextheirmuscles,buttheywouldnotbecomeindependentuntilthenextyear.

“TheFlerovLaboratoryofNuclearReactions[atJINR],wherewedidourexperiments,wasfoundedbyoneofthegiantsofRussiannuclearphysics,”saysMoody,whoisstillinvolvedinthecollaboration.Asithappened,FlerovdiedshortlyaftertheLivermoreteamarrivedin1990,andhewasburiedwithhonorsinthesamecemeteryastheRussianplaywrightAntonChekhov.

AlthoughFlerov’sdeathputadamperonworkattheinstituteforthedurationoftheLaboratoryscientists’visit,LougheedandMoodywouldimproveanenergy-andposition-sensitivetechnologythatisstillbeingusedatJINR.Developmentofagas-filledmassseparatortoremoveunwantednucleifromdesirednucleitookmanyyears.Finally,in1999,thecreationoftheheaviestknownelementsbeganinearnest.

JINR,devotedsolelytonuclearresearchofalltypes,isnowalmostaslargeasLawrenceLivermorewith5,500staffmembersfromallovertheworld.Ithousesacceleratorsandcyclotronsofvaryingenergiesforanarrayofexperimentsandcommercialapplications.

CreatingNewElementsThenumberofanelementintheperiodic

table—itsatomicnumber—isdefinedbythequantityofprotonsinitsnucleus.Mostelementsinthelowerreachesoftheperiodictable—thegasesandstableelementssuchasiron,copper,andcalcium—havebeenknownforhundredsofyears.Moreunusualareelements43(technetium)and61(promethium),whichwereisolatedandidentifiedonlywithgreatdifficultyaftermanyyearsofresearch.Element43,whichwascreatedinanItalianlaboratoryin1937,isthelowestatomic-numberelementwithoutanystableisotopes.

Livermore–Dubna CollaborationS&TR October/November 2010


In 1990, Livermore’s Ken Moody (left) and Ron Lougheed (center) joined

Academician Yuri Oganessian (right), head of the Flerov Laboratory of

Nuclear Reactions in Dubna, Russia, to toast the beginning of what became

a 21-year collaboration to create superheavy elements.

calciumionshastobombardthespinningcaliforniumtargetwithenoughforcetofusewiththecaliforniumbutnottransferenoughenergytobreakapartthenucleus,orfission.

Researchershadinitiallyskippedoverelement117becauseofdifficultyobtainingthenecessarytargetmaterial,berkelium(element97).Eventually,atwo-yearexperimentalcampaignwasbegunattheHighFluxIsotopeReactoratOakRidgeNationalLaboratorywiththegoalofproducing22milligramsofberkeliumtodiscoverelement117.A250-dayirradiationperiodwasfollowedby90daysofprocessingatOakRidgetoseparateandpurifytheberkeliumtargetmaterial.CollaboratorsattheResearchInstituteforAdvancedReactorsinDimitrovgrad,Russia,thenpreparedthetargets.Overthenext150days,theradioactiveberkeliumtargetswerebombardedwithcalciumionsintheU400cyclotronatJINR.Finally,bothLivermoreandJINRanalyzedthedata.Theentireprocesswasdrivenbythe320-dayhalf-lifeoftheberkeliumtargetmaterial.

anticipatedhalf-livestosecondsorminutesbeforetheelementbegantodecay.Half-livesofsecondsorminutesmayseembrief,butsomeatomshaveextremelyshorthalf-lives.Forexample,element110hasisotopeswithhalf-livesrangingfrom100microsecondsto1.1milliseconds.

Invividcontrast,anatomofelement114,createdbyLivermoreandJINRscientistsin1999,survivedfor30secondsbeforeitbegantodecay—aspontaneousprocessthatleadstothecreationofanotherelementwithalowernumberontheperiodictable.Atotalof34minuteselapsedbeforethefinaldecayproductfissioned,splittingintwothesurvivingnucleus.Theselifetimesaremillionsoftimeslongerthanthoseofpreviouslysynthesizedheavyelements.Theislandofstabilityseemedtantalizinglyclose.

In2000and2001,thecollaborationusedJINR’sU400cyclotron,oneoftheworld’smostpowerfulheavy-ionaccelerators,tocreateelement116inthehopeofproducingdecayisotopesofelement114. Althoughtheteamdidcreateseveralotherisotopesrepeatedly,someofwhichhavesincebeenduplicated,thelonglifetimeofthefirstatomofelement114with175neutrons(114-289)hasnotbeenreplicated.Similarly,element118,createdin2006,lastedlessthanamillisecondbeforedecaying.

TheChallengesofElement117Inbombardingoneelementwithanother,thenumberof

protonsinthetwoelementsaddsuptotheprotonsinthedesirednewelement.Inelement118experiments,californium,whichhas98protons,isfusedwithcalcium,whichhas20.Thebeamof


New elements come to life, one atom at

a time, in the U400 cyclotron at Flerov

Laboratory of Nuclear Reactions.

Livermore–Dubna Collaboration


DawnShaughnessy,whohasmadefourvisitstoJINR,noticedCoca-Cola®inanevenlargersupermarketduringhermostrecentvisitinSeptember2009.ApostdoctoralfellowfromDubna,thefirsttocometotheLaboratory,arrivedthisfall.AccordingtoShaughnessy,heknowsafreedomtotravelandanavailabilityofgoodsthatsurpassthoseexperiencedbyhispredecessorsinthecollaboration.

TheU.S.–Russianteamsharesyetanothercommonality:thedesiretocontinuethesearchforelementswithpropertiesunlikeanyothers.SaysShaughnessy,“Eachnewelementwediscoverprovidesmoreknowledgeabouttheforcesthatbindnuclei

andwhatcausesthemtosplitapart.Thisknowledge,inturn,helpsusbetterunderstandthelimitsofnuclearstabilityandthefissionprocess.”

Andwhatofthenextelementsontheperiodictable?“Dubnaisplanningtoupgradetheacceleratorweuse,increasingtheintensityoftheionbeamsitproduces,”saysShaughnessy.“Anotherexpectedchangeisthattheacceleratorwillbecapableofproducingbeamsofelementsotherthancalcium.”Fusingironandplutoniumtocreateelement120willrequirecrushingenergiesandawholenewionelementalbeam.

—Katie Walter

Key Words:JointInstituteforNuclearResearch(JINR),periodictable,superheavyelements.

For further information contact Dawn Shaughnessy (925) 422-9574


Theexperimentalcampaignproducedsixatomsofelement117,eachofwhichdecayedtoelement115,113,andsoonuntilfissioning.Theobserveddecaypatternsinthenewisotopescontinuethegeneraltrendofincreasingstabilityforsuperheavyelementswithincreasingnumbersofneutronsinthenucleus.AsLawrenceLivermoreDirectorGeorgeMillerhasnoted,“Thediscoveryprovidesnewinsightintothemakeupoftheuniverseandisatestimonytothestrengthofscienceandtechnologyatthepartnerinstitutions.”However,truestabilityhasnotbeenfound.Theislandofstabilityisnearandyetstillfar.

CommonalitiesThatMatterMoodyhasvisitedRussiaseventimes,takingnewmembers

oftheLivermoreteameachtrip.Henotes,“Thecountryhasbecomemorewesternizedwitheveryvisit.”Byhisfourthtrip,DubnahadaWestern-stylesupermarket,whichwasbeginningtoreplacetheindividualmeat,bread,andvegetablestalls.Chemist

Livermore researchers (from left) John Wild

(now retired), Dawn Shaughnessy, and

Mark Stoyer flank a statue of Georgy Flerov,

the nuclear physicist for whom the Flerov

Laboratory of Nuclear Reactions is named.

Livermore–Dubna CollaborationS&TR October/November 2010


ANimmigrantfromChinaandthefirstcollege-boundmemberofhisfamily,ZhiLiaopuzzledoverchoosingacareer.Career

preferencetestsindicatedhewouldmakeanidealairtrafficcontroller,soheheadedtocollegewiththatsuggestioninmind.However,ittookajunior-yearsummerinternshipatLawrenceLivermoreinlaseropticsforLiaotofindanenduringvocationalpassion.“Untilmyinternship,Ididn’tknowwhatitislaserscientistsdo,”saysLiao.“Asasummerintern,Iwasinspiredtolearnmore,andIwantedtocomeback.”HecamebacktodoresearchatLivermoretwicemorewhileworkingtowardhisPh.D.inoptics,andthethirdtimetostay,asastaffscientistattheNationalIgnitionFacility.

Students and Researchers Partner for Summer Projects

ResearchHighlights S&TR October/November 2010


NIF scientist and former intern Zhi Liao (second

from left) works with his summer interns. Like

many Lawrence Livermore researchers, Liao sees

mentoring students as a way to give back to the

community and help train future scientists.

Eachyear,theLaboratorywelcomesseveralhundredstudentswhospendtheirsummerassistingLivermorescientistswithresearch.Internshipopportunitiesduringtheacademicyearareexpandingbutstilllesscommon.AccordingtoBarryGoldman,managerofmanystudentinternshipprogramsandmemberofLivermore’sStrategicHumanResourcesManagementorganization,thesummerinternshipexperienceismostoftenaconfirmationthatstudentshavechosenacareerpathandcourseofstudythatsuitthem.Butforsome,suchasLiao,directexposuretotheLaboratory’srobustanddiverseresearchprogramsisarevelation,leadingstudentsinadirectiontheyhadneverbefore

S&TR October/November 2010 Summer Student Internships


teammembers—inaccordancewithprojectgoalsandcriteriadeterminedbetweenthem.

LiaonowhostshisownsummerstudentsandalsomanagestheStudentInternshipProgramfortheNationalIgnitionFacility.Ashehelpsmatchstudentswithprojects,Liaoworkstoensurethatinternshipsareformulatedtobenefitbothparties.“Weneedtomakesurethattheprojectsareappropriateforboththementorandstudent,”saysLiao.“Abalanceisrequiredtokeepthestudentsinterestedandproductive.”

AttentiontothelearningcomponentofinternshipsmakessummersattheLaboratoryafarcryfromthecoffeemakingandpapershufflingofastereotypicalinternship.Here,internsmakerealcontributionstoresearchprojects.KlintRose,engineerandwinnerofaDOE2009OutstandingMentorAward,says,“Iputmystudentsrightonthecriticalpath.Theydorealprojectswithrealimpacts,andtheresultisthattheyappreciatemakingacontribution.”Rose’sinternshavemadeessentialpresentationsandconducteddemonstrationsforhigh-profileaudiences.AsaformerLivermoreinternhimself,heunderstandswhatstudentsarehopingforfromaninternship.“Mystudentexperiencehelpsmeknowwhatisreasonableasasummerproject,whatwillhelpastudentgrowandnotjustbebusywork,”saysRose.

LearningExperienceforMentorsandStudentsAlikeJohnKnezovich,alsoaformersummerstudent,isdirectorof

StrategicUniversityRelations,theLaboratory’spointofcontactforallDOEsummerprograms.AccordingtoKnezovich,whatcatchesstudentsbysurpriseishowresearchersdispensewithtitlesandhierarchyandtreatthemasteammembersandcolleagues.“Studentsandresearchersgettheirhandsdirtytogether,solvingproblems,”saysKnezovich.“Studentsappreciateandseethevalueofinterdisciplinaryteams,whichisthehallmarkofwhatwedo.”Notonlyistheinterdisciplinary,egalitarianworkenvironmentarefreshingcontrastformanystudentsfamiliarwiththemorerigiddisciplinesandtraditionalhierarchiesofauniversitysetting,butitalsointroducesstudentstofounderErnestO.Lawrence’svisionofteamscience—solvingseeminglyintractableproblemsusingallavailabletoolsandresources.

Solidcareerexperience,realresponsibilities,andtreatmentasapeerarewhatstudentsvaluemostaboutaLivermoreexperience,accordingtoexitsurveysconductedbyGoldman.Thesefeaturesattractandretainstellarstudents.Afullquarterofthissummer’sinternsarestudentswhohavereturnedtotheLaboratorytocontinuetheirresearchorexploreanewtopic.AllundergraduateinternsareencouragedtosubmitabstractsandpaperstoDOE’sJournal of Undergraduate Researchattheendofthesummer—formany,theirfirstopportunitytopublishresearch.Sometimes,discoveriesduringsummerinternshipshaveevenledtouniqueopportunitiesforstudentstocoauthorpapersorcopresentpostersatascienceconference.PhysicistDonCorrellofthePhysicalandLifeSciencesDirectoratehasbeeninvolvedwithstudentprograms

imagined.Goldmansays,“Oneneverknowswhatmightsparkorfocusastudent’sinterest.”

AspiringAuditorsChooseLivermore,TooLivermorepaidandunpaidinternshipsareprimarilyavailable

inscience,engineering,andtechnology,theLaboratory’swell-knownstrengths.Butopportunitieshavealsobroadenedinrecentyearstoincludeotheressentialdisciplinesthathelpkeepahighlyrespectednationallaboratoryrunningsmoothly.Internshipsinareassuchaslaw,finance,andprojectmanagementintroduceabroadercrosssectionofstudentstotheLaboratoryandwhatithastooffer.CollegejuniorMattSpaurrecentlycompletedhissecondsummerinLivermore’sIndependentAuditandOversightDepartment,reviewingexpensereports,conductinginterviews,andverifyingpayroll,amongotherauditingtasks.BeforeSpaurbeganhisinternshipsearch,hehadneverheardofLawrenceLivermorenorhadheanyexperienceinauditing.Now,aftertwosummersofintensiveandrewardingon-the-jobexperience,thebusinessadministrationmajorintendstopursueacareerasanauditor.“Togethands-onexperienceinacareerIaminterestedinispriceless,”saysSpaur.

SummeropportunitiesattheLaboratoryareavailableformaturestudentsatallstagesofcareerexplorationandstudy,fromtheoccasionalexceptionalhighschoolstudenttoeagerundergraduatestudentsandgraduatestudentswhohavefinelyhonedtheirresearchpassion.MoststudentsarehiredforthesummeraspaidinternsthroughtheScholarEmploymentProgram.Thissummer,just240studentswereacceptedtotheprogram,outofseveralthousandapplicants.

Asmallerbutgrowingnumberofstudents—158thissummer—arebroughtinthroughtheAcademicCooperationProgram,theLaboratory’sunpaidinternshipprogram.Inthisprogram,astudentmayreceivecoursecreditormaybesponsoredbyanexternalagencysuchastheDepartmentofHomelandSecurityortheDepartmentofEnergy’s(DOE’s)NationalNuclearSecurityAdministration.ThesetwopathstocovetedLaboratoryinternshipsattractmotivatedstudentsfromacrossthenationwithstrongacademiccredentials.

RealWork,NotBusyworkInternshipsatLivermoreofferstudentsmuchmorethan

animpressiveresumeentry—theygivestudentsthetimeandresourcesneededtoexpandordevelopcareer-relatedskillsandtheopportunitytoreceivespecializedtrainingandexperiencefromprofessionalsintheirfield.Opportunitiesoriginatewithresearchersorstaffmembers,whoneedstudentassistanceonaprojectandeitherposttheprojectontheLaboratory’sjobsWebsite(careers.llnl.gov)orindicatetheirinterestandavailabilitytothemanagerofaparticularinternshipprogram.Onceastudentandresearcherarepairedbytheprogrammanager,thestudentassiststheresearcherduringthesummeracademicbreak—whetherinthelaboratoryoratacomputer,workingone-on-oneorwith

S&TR October/November 2010Summer Student Internships

22

goontoacademia,theymaysendstudentstoLivermoreaswellashaveadesiretocollaborate.”PastinternshipshaveledtofruitfulprofessionalpartnershipsbetweenformerstudentsandLaboratoryresearchers.

EventsSpurFriendshipandNetworkingGoldmanhasbeenmanagingvariousLivermoreinternship

programsfor12years.OneofhismostenduringcontributionsisthecreationoftheInstitutionalEducationCommittee(IEC),whichincludesrepresentativesfromdepartmentsacrosstheLaboratory.Thecommitteeplansabroadrangeofsummeractivitiestoengagestudentsofvariousagesandinterests.EventsthissummerincludedtoursoftheJointGenomeInstituteinWalnutCreek,California,andLivermore’sHighExplosivesApplicationsFacility;socialactivitiessuchasbarbecuesandanever-popularraftingexcursion;researchtalksandpaneldiscussionsbyscientists;andseminarsonthepracticeofscience,includingunderstandingpatentsandhowtowriteanabstract.TheseeventsareoptionalandopentoallLaboratorystudents.

Rosechosetospendhissummerinternshipsworkingmostlyathisdeskorinthelab,withlimitedsocialinteraction,headmitswithalaugh.Hehascometovaluethestudentactivitiesandnowencourageshisstudentstotakefulladvantageoftheofferings.Notonlyaretheactivitiesanopportunitytomeetstudentsandresearcherswithwhomtheymaylaterinteract,buttheeventsalsoexposestudentstothebreadthofresearchperformedattheLaboratory.Studentscanbesurprisedtodiscoverthatsome

invariouscapacitiesformanyyears.Henotes,“AsummerattheLabraisesthelevelofscientificknowledgeforstudents.Theyexperiencethehighestcaliberofresearch.Individualmentorsarethepeoplewhomakeallofthispossible.”

Formentors,theexperiencehasitsownrewards.Manymentorsareformersummerstudentsthemselveswhoviewmentoringasawaytogiveothersthesameopportunity.BothRoseandLiaomentorseveralstudentseachyear.Internsnaturallybringextrahelptoshort-handedprojects,buttheyalsoprovideafreshperspective,someonewhomayquestionaprocessandcauseresearcherstorethinktheirassumptionsormethods.Workingwithstudentsalsogivesmentorsachancetoexercisetheirteachingandmanagerialskills.AccordingtoGoldman,“MentoringhelpsLivermoreresearchersretaintheirconnectiontoacademia,toseewhatisbeingtaughtandwhichtechnologiesarebeingusedforresearch.”Selectmentorsgainbroaderrecognitionfortheireffortsthroughthestudent-nominatedOutstandingMentorAwardProgramadministeredbyDOE’sOfficeofScience.

Long-TermConnectionsStartwithInternshipsHostingoutstandingstudentinternsisawin–winsituation.

Goldmanseessummerprogramsasanopportunitytobuildalong-termrelationshipwithstudentsandestablishLivermoreintheirmindsasaleadingscientificlaboratory.OneAcademicCooperationProgramthathemanages,theMilitaryAcademicResearchAssociate(MARA)Program,bringsmidshipmen,cadets,andfacultyinU.S.militarybranchestotheLaboratoryforamonth—onlyone-thirdthelengthofmostinternships—toexperienceLivermore’sresearchofferings.MARAisamodelprogramfortheNationalNuclearSecurityAdministration,whichislookingtoexpanditsnationallaboratory–militarycollaborations.Theprogramenablesacademyinstructorstoexpandandbuildontheirteachingcurriculum.Inaddition,itgivesfuturemilitaryofficersfamiliaritywithandrespectfortheLaboratoryandhowitsresearchcontributestotheDepartmentofDefense.

AccordingtoGoldman,thesummerprogramsalsofunctionasa“pipeline”toattractpromisingstudentstoacareeratLivermore.ManyLaboratoryresearchersandadministratorsareformersummerstudents,includingDirectorEmeritusBruceTarter.WhilenotallofthestudentswillreturntoworkatLivermoreaftergraduating,otherlong-termbenefitsareseeninbringinginsummerstudents.SaysGoldman,“Ifstudentsgoontoworkinindustry,theopportunitymayariseforfurthercollaboration.Ifthey


Livermore summer interns from the Military Academic Research Associate

Program, ROTC, and other student programs pose at Pony Tracks, a

collection of tanks, in nearby Portola Valley, California. Occasional student

field trips to relevant science, engineering, and national security destinations

supplement their daily internship tasks.

S&TR October/November 2010 Summer Student Internships

23

long-timeemployeeshavehadmultiplecareerswhileattheLaboratorybecauseofthediversityofresearchofferings.

Asummerhighlightisthestudentpostersymposium,heldeveryAugustandattendedbymanyLivermoreresearchers.Thiseventismodeledafterthepostersessionsataprofessionalscientificmeeting,andallsummerstudentsareinvitedtoparticipate.Correll,oneofthecreatorsofthestudentpostersession,ispleasedwiththeresults.Hesays,“WhenLabscientistscome,theyseewhatthey’dfindataprofessionalsession.Thestudentsproduceanexcellentsetofposters.”Manymentorsencouragestudentstostartthinkingabouttheirpostersassoonastheyarrive.AccordingtoCorrell,theposterworkforcesstudentstoconsidernotonlyhowtopresenttechnicalcontentbutalsohowtocreateapleasingandinstructivevisualpresentation—usefulprofessionalskillsinmostanyfield.Thepostersessionoffersasatisfyingconclusiontoasummerofcareerimmersionandhands-onexperience.

TheLaboratory’senduringrelationshipwiththeUniversityofCaliforniahasimbueditsstaffwithstrongsupportandrespectforeducationandcareerpreparationopportunities.Fewerhighschoolsoffercareercounselingservices,andyetmanymorestudentsattendcollege,manyofwhomarethefirstintheirfamilytodoso.Thenationhasastrongneedforinstitutionstoprovideopportunitiesthatguidestudentstowardagoodcareermatchandencourageoutstandingstudentstoconsidergraduate-leveleducation.TheLaboratory’sinternshipsareavaluableresourceforinspiringstudentsandhelpthemsteeraconfidentcoursetowardtheirfuturecareer.

LaboratorymanagementstronglysupportsandvaluesthesummerstudentprogramsandwhattheyofferboththeLaboratoryandthestudentcommunity.“SummerstudentsgiveasmuchormoretotheLaboratoryastheyreceivefromus,”saysLaboratoryDirectorGeorgeMiller.“Theybringaspecialcuriosityandenthusiasmforlearning.Theyoftenenergizeprojectteamsandrekindleourthirstforknowledge,remindingusofthereasonswechosecareersatanationallaboratory.”Whethersummerstudentscontinueontograduateschoolorentertheworkingworld,exposuretotheLaboratory’sinnovative,multidisciplinaryapproachtotacklingtoughprojectsprovidespracticalexperiencethattheycandrawontimeandagain.

—Rose Hansen

Key Words:AcademicCooperationProgram,InstitutionalEducationCommittee,MilitaryAcademicResearchAssociate(MARA)Program,OutstandingMentorAward,ScholarEmploymentProgram,StudentInternshipProgram.

For further information contact Barry Goldman (925) 422-5177



A student discusses her summer research results with Livermore physicist

Don Correll at a student poster symposium. Held each August, the event

is modeled on professional scientific poster sessions and offers students

presentation experience and networking opportunities.



thendepositedviaasolventlessvaporontothemembranesubstrateinthechamber.Themembranesubstrateandthemonomermixtureareheatedtoproduceinsitupolymerizationandprovidethecompositemembrane.

Real-TimeMultiplicityCounterMarkS.Rowland,RaymondA.AlvarezU.S. Patent 7,755,015 B2July 13, 2010Aneutronmultidetectorarrayfeedspulsesinparalleltoindividualinputstiedtoindividualbitsinadigitalword.Dataarecollectedbyloadingawordattheindividualbitlevelinparallel.Thewordisreadatregularintervals,allbitssimultaneously,tominimizelatency.Theelectronicsthenpassthewordtoseveralstoragelocationsforprocessing,therebyremovingthefront-endproblemofpulsepileup.

AbsoluteNuclearMaterialAssayManojK.Prasad,NealJ.Snyderman,MarkS.RowlandU.S. Patent 7,756,237 B2July 13, 2010Thismethodproducesanabsolutenuclearmaterialassaybycountingneutronsfromanunknownsourceandcomparingthemeasuredcountdistributionstoamodel.Onesetupusesarandomsamplingofanalyticallycomputedfissionchaindistributionstogenerateacontinuoustime-evolvingsequenceofeventcountsbyspreadingthefissionchaindistributionintime.

bodyofcontributionstophysicsaswellasindividualprojectsandresearchachievements.HehasbeeninvolvedindifferentapproachestoandaspectsoffusionenergyfromNIFtotokamakmagneticfusionreactorsandtheZ-pinchmachinedevelopedbySandiaNationalLaboratories.RyutovisalsoamemberofoneofLivermore’s2010R&D100Award–winningteams.(Seethehighlightonp.8.)

Hispassionfortakingonphysicsproblemsindiverseresearchareashasbeenadrivingforceofhiscareer.RyutovisatheoreticalphysicistwhothrivesintheLaboratory’smultidisciplinaryteamscienceculture.HisfirstcontactwithLivermorewasinthelate1970sthroughaSoviet–Americanresearchcollaborationonmagneticmirrors,whenhewasascientistattheBudkerInstituteofNuclearPhysicsinSiberia.

Bryan BalazsoftheWeaponsandComplexIntegrationPrincipalDirectoratewaselectedfellowoftheAmerican Chemical Society(ACS).BalazsisanassociateprogramleaderinBProgram,whichreceivesitsfundingthroughacomplicatedsetoffundingstreams,andeachsourcehasitsownoversightandreportingrequirements.Balazs’sjobentails,ashedescribesit,“untanglingthefinancialknots”aswellasdealingwithbudgetary,planning,andperformancemetrics.

MagnetohydrodynamicPumpwithaSystemforPromotingFlowofFluidinOneDirectionAsuncionV.Lemoff,AbrahamP.LeeU.S. Patent 7,753,656 B2July 13, 2010Thismagnetohydrodynamic(MHD)pumphasamicrofluidicchannelforchannelingfluid,anMHDelectrode–magnetsystemconnectedtothechannel,andasystemforpromotingfluidflowthroughthechannelinonedirection.Thepumpcanbeusedbythemedicalandbiotechnologyindustriesinblood-cell-separationequipmentandbiochemicalassaysandforchemicalsynthesis,geneticanalysis,drugscreening,anarrayofantigen–antibodyreactions,drugtesting,medicalandbiologicaldiagnostics,andcombinatorialchemistry.Thepumpcanalsobeusedinelectrochromatogaphy,surfacemicromachining,laserablation,ink-jetprinters,andmechanicalmicromilling.

PreparationofMembranesUsingSolvent-LessVaporDepositionFollowedbyIn-SituPolymerizationKevinC.O’Brien,StephanA.Letts,ChristopherM.Spadaccini,JeffreyC.Morse,StevenR.Buckley,LarryE.Fischer,KeithB.WilsonU.S. Patent 7,754,281 B2July 13, 2010Inthissystemforfabricatingacompositemembranefromamembranesubstrate,solventlessvapordepositionisfollowedbyinsitupolymerization.Firstandsecondmonomersaremixedinadepositionchamberandare

Tammy Ma,aLawrenceScholarandpostdoctoralresearcherintheNationalIgnitionFacility(NIF)andPhotonSciencePrincipalDirectorate,hasreceivedthe2010 Mechanical and Aerospace Engineering Award for Outstanding Graduate StudentfromtheUniversity of California at San Diego (UCSD).Herdoctoralthesis,“ElectronGenerationandTransportinIntenseRelativisticLaser–PlasmaInteractionsRelevanttoFastIgnitionICF,”wascompletedunderthesupervisionofSanDiegoProfessorFarhatBegandNIFresearcherAndrewMacPhee.Herresearchwascloselyconnectedtofastignitionandhigh-energy-densityscience.

MastartedasaLawrenceScholarin2008,butthatwasnotherfirsttimeattheLaboratory.In2001,whileastudentatMissionSanJoseHighSchoolinFremont,California,sheworkedasasummerinternintheLaboratory’sInstituteforGeophysicsandPlanetaryPhysics.Inaletterinformingheroftheaward,DepartmentChairSutanuSarkarwrote,“GraduatestudentsplayapivotalroleinourdepartmentandatUCSD.Youhavebeenveryproductiveinresearchrelatedtoelectrontransportandlasermatterinteractions,asevidencedthroughpublicationinreputedjournals.”

Physicist Dmitri Ryutovreceivedthe2010 Distinguished Career AwardfromFusion Power Associatesforhiscontributionstofusionresearch.TheawardrecognizesRyutov’s

Patents

Awards

In this section, we list recent patents issued to and awards received by Laboratory employees. Our goal is to showcase the distinguished scientific and technical achievements of our employees as well as to indicate the scale and scope of the work done at the Laboratory.

PatentsandAwards

www.llnl.govU.S.GovernmentPrintingOffice:2010/670-075-71023

Carbon Dating Advances

Climate Science

TheCenterforAcceleratorMassSpectrometryhasbecomeanessentialresourceforhelpingscientiststounderstandclimatechange.

Also in December• Sophisticated diagnostic equipment installed at the National Ignition Facility will measure the key physical processes occurring in high-energy-density experiments.

• A new device developed at Livermore can detect and identify thousands of viruses and bacteria simultaneously in a day.

• The Laboratory’s technique for sequestering carbon dioxide underground shows promise for mitigating the effects of this greenhouse gas while producing freshwater.

Co

mi

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HejoinedtheLaboratoryin1992asapostdoctoralfellow,developingsensorstomeasureeffluentstreamsandoxygenunderhightemperaturessuchasinautomobileengines.Balazstransitionedintotheweaponsprogramin1998,studyingmaterialsissuesassociatedwithnuclearweapons,developingadvanceddiagnosticsforstockpilemeasurements,andcontributingtothedevelopmentofscientificlifetimemodelsbasedonagingtrendsobservedinthestockpile.HehasbeenactiveinACSnearlyhisentiretenureattheLaboratory.

Ed Moses,principalassociatedirectoroftheNIFandPhotonSciencePrincipalDirectorate,isaregionalwinnerofaJefferson Awardforhiseducationoutreachinthecommunity.Mosesroutinelyvolunteershistimetoengagewithandlecturetostudentsandthegeneralpubliconphysics,lasers,andphotonscienceaswellasNIF,theworld’slargestlaser.TheJeffersonAwardswerecofoundedin1972byJacquelineKennedyOnassistohonorvolunteerismandcommunityoutreachthroughouttheU.S.Theawards,namedforThomasJefferson,arepresentedontwolevels:nationalandregional.

TheFederal Laboratory Consortium’s Far West RegioncompetitionawardedLawrenceLivermoretwohonors.LaboratoryemployeesJohn Dzenitis,Vincent Riot,andCatherine ElizondoreceivedanOutstanding Partnership AwardfortheirpartneringeffortswiththeMontereyBayAquariumResearchInstituteandSpyglassBiosecurity,Inc.,inthedevelopment,transfer,andlicensingofareal-timeenvironmentalsamplerforconductingbiologicalanalyses.LaboratoryscientistsTom Slezak,Crystal Jaing,Shea Gardner,andKevin McLoughlinreceivedtheOutstanding Technology Development Award fortheirworkindevelopingamicroarraythatcandetectmorethan2,000virusesand900bacteriain24hours.

PhysicistPrav Patelreceivedthe2010 Excellence in Fusion Engineering AwardfromFusion Power Associatesforhisworkinrelativisticlaser–plasmainteractionandleadershipindevelopingthefast-ignitionconceptforinertialconfinementfusion.“Itreallyrepresentstheaccomplishmentsoftheentirefast-ignitionteamhereatLivermore,”saysPatel.

Pateljumpedrightintothefieldofrelativisticlaser–plasmainteractionandfastignitionwhenhearrivedattheLaboratory11yearsago.Asapostdoctoralresearcher,hestartedhisworkinhigh-intensity,short-pulselasersatLivermore’sJupiterLaserFacilityusingfirstthe100-terawattCallistolaserandthenthepetawatt-classTitanlaser.

TheExcellenceinFusionEngineeringAwardwasestablishedin1987torecognizepersonsintherelativelyearlypartoftheircareerswhohaveshownbothtechnicalaccomplishmentsandpotentialtobecomeexceptionallyinfluentialleadersinthefusionfield.

Science & Technology ReviewLawrence Livermore National LaboratoryP.O. Box 808, L-664Livermore, California 94551

PRSRT STDU.S. POSTAGE

PAIDAlbuquerque, NMPERMIT NO. 853

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