constpppppppppp pppppure) - astrophysik.uni-kiel.dekiel2014/main/contribute/poster/schywek.pdf ·...
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MathiasfSchywekBfJensfTeiserfandfGerhardfWurm
ConstrainingPthePFormationPofPCompoundPChondrulesPinPthePSolarPNebula:PCollisionPExperimentsPatPVaryingPViscosityP(Temperature)
f–ompoundf chondrulesf eAgAf aref thoughtf tof havef collidedf whilef stillf hotf andf viscousf butf furtherfconstrainsfarefnotfknownfUGoodingfandfKeilfU3°H3?BfWassonfetfalAfU3°°-??AfUnderfwhatfconditionsfdofviscousfparticlesfstickftogetherRffLowfviscosityfmightfbefbeneficialfforfstickingfatflowfcollisionfvelocitiesf butf iff twof dropletsf collidef violentlyf theyf justf splashf intof numerousf smallerf dropletsfU:rennf andf Frohnf U3°H°??Af ThereforeBf theref willf bef differentf velocityf thresholdsf separatingfcollisionalf outcomesAf Vnotherf questionf forf reboundingf viscousf particlesf isf whatf energyf fractionfremainsfasfkineticfenergyforfhowfwellfdofcollisionsfdampfanfinitialfreservoirfofffastfparticlesAfForfchondrulesfatfafcertainftemperaturefonlyfafcertainfvelocityfrangefwillfresultfinfcollisionsAf–ollisionalfoutcomesf off viscousf particlesf havef tof bef consideredf forf chondrulef andf especiallyf compoundfchondrulefformationAfForfafgivenfsilicatefatfdifferentfUhigh?ftemperaturesBfviscosityfisfthefobviousfparameterfthatfchangesfdrasticallyA
3? 4? 6?
x? -? 0?
WeffurtherfconductedfcollisionfexperimentsfoffsmallfbasaltfparticlesfU4Fxfmmfdiameter?fthatfwerefheatedfupfonfaf ceramicf mountingAf Vfterf releasef thef particlef fallsf onf af ceramicf surfacef notf furtherf thanf af fewf centimetersfresultingf inf af collisionf speedf off roughlyf 2AHf mqsAf Thef irregularf shapef off thef particlef resultsf inf af numberf offdifferentf collisionf outcomesf andf thusf resultingf inf af largef variationf regardingf thef coefficientf off restitutionAfHoweverfthefresultsfoffourfinitialfcollisionfexperimentsfshowfafnotablefdecreasefinfthefcoefficientfoffrestitutionfwithftemperaturesfoffoverf3222°–AfThefmeasuredftemperaturefisfthefmeanftemperaturfoffthefsurfacefexplicitlyftouchingfthefceramicfsurfacefandfnotfthefoftenfmuchfhigherfcoreftemperaturefoffthefparticleA
Ourf goalf isf thef collisionf off heatedf orf almostf meltedf materialfanalogftofthefchondrulesAfForfthefheatingfprocessfwefusefaflaserfwithfafmaximumfopticalfoutputfoffx2fWattAfThefmaterialfinfusefisfbasaltf inf formf off smallf basaltf chipsf whichf aref eitherf lyingf onf afceramicfsurfaceforffmountedfonfsmallfceramicftubesA
Thef firstf stepf off ourf experimentf wasfthef calibrationf off af highFspeedFcameraAf Inf af seriesf off picturesf wefdeterminedf thef correlationf off thefbrightnessf receivedf byf thef camerafandf thefmeasuredf temperaturefoff thefsampleAfThisf isf convenientf forf furtherfimagef processingf asf wellf asfnecessaryf sincef ourf thermographicfcameraf isf limitedf tof af maximumftemperaturefoff°-2°–A
3? 4?
6? x?
6fmm
EvolutionfoffchondritesfinfthefProtoplanetaryfNiskfUScottBfEdwardfRANAfU3°°/??
PlanetPFormationPandPEvolutionP2014
6fmm
HighFSpeedf–amera
Sample
Lensfsystem
Vacuumchamber
–eramicfmount
3? 4? 6?
x? -? 0?
ReferencesOScottBfEdwardfRANAfU422/BfMai?Bf–hondritesfandfthefProtoplanetaryfNiskBfVnnualfReviewfoffEarthfandfPlanetaryfSciencesBfvolAf6-BfIssuef3BfpA-//F042A:rennBfGABfFrohnBfVAfU3°H°BfJuly?Bf–ollisionfandfmergingfofftwofequalfdropletsfoffpropanolBfExperimentsfinfFluidsBfVolumef/BfIssuef/BfppAxx3Fxx0AGoodingfJAfLAfandfKeilfKAf3°H3AfRelativefabundancesfoffchondrulefprimaryftexturalftypesfinfordinaryfchondritesfandftheirfbearingfonfconditionsfoffchondrulefformationAfMeteoriticsf30O3/–x6AWassonfJAfTABfKrotfVAfNABfMinfSAfLABfandfRubinfVAfEAf3°°-Af–ompoundfchondrulesAfGeochimicafetf–osmochimicafVctaf-°O3Hx/–3H0°Afff
FirstPcollisionPexperiments:
SetupPandPCalibration:
Introduction:
:asaltfchipsff
:asaltfchipfatfincreasingftemperatureff
–orrelationfofftemperaturefandfbrightnessff
–ollisionfsequenceff
–oefficientfoffrestitutionfatfhigherftemperaturesffff