Vacuum equipment

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1、VacuumequipmentPumpsRotaryvanepumpsRotarypistonpumpsRootspumpsTurbomolecularpumpsDiffusionpumpsGetterpumpsSublimationpumpsNon-evaporablegetterpumpsIonpumpsElectrostaticpumpsSputter-IonpumpsCryogenicpumpsRotaryvanepumpsPressurerange1to105Pa10to200m3/hRoughpumpingBackingfordiffusionandturbopumpsRot

2、arypistonpumpsRoughingpumpsIncombinationwithRoots30to1500m3/hRuggedandsimpleRootspumpsPositivedisplacementblower3000to3500rpmTwolobedrotorsonparallelshaftsPumpingspeed:nx100m3/hTurbopumpsHighspeedturbineDownto10-8PaVanespeedhigherthanmolecularspeed100–500m/sMomentumtransferDiffusionpumpsVaporjetM

3、omentumtransferonoilcollisionwiththevaporstreamUltimatepressure10-10PaGetterpumpsGasmoleculescollideandreactwiththesurfaceSublimationpumpisasurfacegetterpumpforactivegasesTitanium:inexpensive,effective,easilysublimedNon-evaporablegetterPumpbysurfaceadsorptionfollowedbybulkdiffusionHightemperature

4、sThefirsttitaniumsublimationgetterpumphasbeenassembledandisbeingtestedinthePBFA-IIIntegratedTestFacilityIonpumpsIonsarepumpedeasilybecausetheyaremorereactivewithsurfacesthanneutralmoleculesBombardingelectronsThepumpisstartedbyapplyinghighvoltagebetweenthetubeshapedanodeandthecathodeoftheionpump.E

5、lectronsareacceleratedtowardthepositiveanodeandareforcedtofollowaspiralpathinthetubeshapedanodebecauseofthemagneticfield.Thishastheeffectofsweepingoutmorespaceandincreasingtheprobabilitythatanelectronwillcollidewithagasmolecule.Thepositiveionsthatareformedinthecollisionsstrikethechemicallyactivet

6、itaniumcathode"getter"plate.Theionscombinewiththecathodematerialandejectmorecathodematerialwhichendsuponthesurfaceoftheanode.Thisconstantlyreplenishedthefilmofchemicallyactivecathodematerialontheanodeswhichcombineswithactivegasmoleculesandeffectivelypumpsthemfromthesystem.Thisprocessofremovingche

7、micallyactivegassessuchasNitrogen,Oxygen,andHydrogeniscalled"gettering".Inertgassesarehandledalittledifferently.Theyareburiedinthepumpsurfaces.Thishappenswhentheyareionizedandhurledintothecathode.Theypenetrateafewlayer