constpppppppppp pppppure) - astrophysik.uni-kiel.dekiel2014/main/contribute/poster/schywek.pdf ·...

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Mathias SchywekB Jens Teiser and Gerhard Wurm Constraining the Formation of Compound Chondrules in the Solar Nebula: Collision Experiments at Varying Viscosity (Temperature) –ompound chondrules eAgA are thought to have collided while still hot and viscous but further constrains are not known UGooding and Keil U3°H3?B Wasson et alA U3°°-??A Under what conditions do viscous particles stick togetherR Low viscosity might be beneficial for sticking at low collision velocities but if two droplets collide violently they just splash into numerous smaller droplets U:renn and Frohn U3°H°??A ThereforeB there will be different velocity thresholds separating collisional outcomesA Vnother question for rebounding viscous particles is what energy fraction remains as kinetic energy or how well do collisions damp an initial reservoir of fast particlesA For chondrules at a certain temperature only a certain velocity range will result in collisionsA –ollisional outcomes of viscous particles have to be considered for chondrule and especially compound chondrule formationA For a given silicate at different Uhigh? temperaturesB viscosity is the obvious parameter that changes drasticallyA 3? 4? 6? x? -? 0? We further conducted collision experiments of small basalt particles U4Fx mm diameter? that were heated up on a ceramic mountingA Vfter release the particle falls on a ceramic surface not further than a few centimeters resulting in a collision speed of roughly 2AH mqsA The irregular shape of the particle results in a number of different collision outcomes and thus resulting in a large variation regarding the coefficient of restitutionA However the results of our initial collision experiments show a notable decrease in the coefficient of restitution with temperatures of over 3222°–A The measured temperature is the mean temperatur of the surface explicitly touching the ceramic surface and not the often much higher core temperature of the particleA Our goal is the collision of heated or almost melted material analog to the chondrulesA For the heating process we use a laser with a maximum optical output of x2 WattA The material in use is basalt in form of small basalt chips which are either lying on a ceramic surface or mounted on small ceramic tubesA The first step of our experiment was the calibration of a highFspeedF cameraA In a series of pictures we determined the correlation of the brightness received by the camera and the measured temperature of the sampleA This is convenient for further image processing as well as necessary since our thermographic camera is limited to a maximum temperature of °-2°–A 3? 4? 6? x? 6 mm Evolution of chondrites in the Protoplanetary Nisk UScottB Edward RANA U3°°/?? Planet Formation and Evolution 2014 6 mm HighFSpeed –amera Sample Lens system Vacuumchamber –eramic mount 3? 4? 6? x? -? 0? ReferencesO ScottB Edward RANA U422/B Mai?B –hondrites and the Protoplanetary NiskB Vnnual Review of Earth and Planetary SciencesB volA 6-B Issue 3B pA-//F042A :rennB GAB FrohnB VA U3°H°B July?B –ollision and merging of two equal droplets of propanolB Experiments in FluidsB Volume /B Issue /B ppAxx3Fxx0A Gooding JA LA and Keil KA 3°H3A Relative abundances of chondrule primary textural types in ordinary chondrites and their bearing on conditions of chondrule formationA Meteoritics 30O3/–x6A Wasson JA TAB Krot VA NAB Min SA LAB and Rubin VA EA 3°°-A –ompound chondrulesA Geochimica et –osmochimica Vcta -°O3Hx/–3H0°A First collision experiments: Setup and Calibration: Introduction: :asalt chips :asalt chip at increasing temperature –orrelation of temperature and brightness –ollision sequence –oefficient of restitution at higher temperatures

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Page 1: ConstPPPPPPPPPP PPPPPure) - astrophysik.uni-kiel.dekiel2014/main/Contribute/Poster/Schywek.pdf · fBfffff ConstPPPPPPPPPP PPPPPure) f –fchondrfAAfffffcollidffffffffurtherf constrainffffUfffU3°H3?BfffAfU3°°-??AfUnderffconditiof

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