低温等离子体表面处理技术.doc

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1、低温等离子体表面处理技术PlasmaandfirstwallIntroductionTodayIwilltalkaboutsomethingaboutmystudyonthefirstwallinthetokamak.Firstly,Iwillshowyouthatwhattheplasmaisinourlifethoughtthefollowingpicturessuchas:Fig.1LighningFig.2AuroraFig.3AstrospaceJustasthepicturesmentionedabove,theyareallconsistofplasma.But

2、,whatdoeshaveintheplasma,nowourscientisthadgivenadefinitionthattheplasmastateisoftenreferredtoasthefourthstateofmatterandcontainsenoughfreechargedparticles（negativeions、positiveions）andelectronics.Likethephotobelow.Fig.4PlasmaproductionPlasmaproductionInourresearch,weproducetheplasmathrough

3、anICP(inductivelycoupledplasma)deviceasfollow：ThroughtheRF(radiofrequency)source、powergeneratorandmatchingbox,wewillgettheplasmaweneedintheexperiment.TheFig.6showsustheplasmaproducedbytheRFsource.Fig.6TheICPplasmaPlasmadiagnosisAndthenweneedtodiagnosetheplasmacharacteristicsthroughsomemetho

4、dslikespectrumandprobe.Fig.7The plane probeWeusedtheplaneprobetodetectionthetemperatureofelectronicsandthedensityoftheplasmaastheFig.8andFig.9.Fig.8electronictemperatureWecanseeamongthepowerof3000w-8000w,thechangeofelectronictemperatureisnotsharp.Andatthepressureof0.258Pa,theelectronictempe

5、ratureisgoingupobviously.Fig.9PlasmadensityIntheFig.9,wecanconfirmthatastherisingofthepower,theparticledensityisalsomoreandmorehigh.Andbeforethepressureof0.42Pa,theparticlesdensityisrisingastheincreaseofthepressure.Buttheparticlesdensityisdroppedafterthepressureof0.42Pa.Andthanweusedthespec

6、trographtodetectiontheparticlesofhydrogenastheFig.11shownus.Fig.10ThePIspectrographFig.11ThehydrogenspectrumWefindthatastheincreasingofthepower,therearefourcurvesoccurred.Butwhenthepowerreachstoabout2000wand4000w,thehaveacapacity.Whenwehaveaclearknowaboutthecharacteristicsoftheplasma.Weuset

7、heplasmatodealwiththefirstwallmaterialssuchasW(tungsten).PlasmainteractionwiththefistwallInourexperiments,weputtheWintheplasma,andacceleratetheHe+particlesorH+usingastaticelectricfieldsothattheycanownapowerfulenergytointeractionwiththematerials.Intheexpe