JEOL FX.docx
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JEOLFX
JEOL2000FX
WiththankstoProfessorJohnF.MansfieldfromtheUniversityofMichiganuponwhoprovidedthehandbookuponwhichtheseinstructionsarebased.
Preamble
1.Notethatthemicroscopeisastate-of-the-artresearchinstrumentandshouldbetreatedwithgreatcarebecausealargenumberofpeoplerelyonitfortheirday-to-daywork.
2.Withtheabovecommentinmind,beforeyoudoanythingtothemicroscope,i.e.insertorwithdrawaspecimenordetector,THINKanddeterminewhetheryouractionisliabletocompromiseanyofthefunctionsoraccessoriesofthemicroscope.
3.Intheinstructionsthatfollowyoushouldmonitorthevacuumstatusoftheinstrumentontheion-gaugemeterand/orthePenninggaugewhileyouareperforminganyactionthatmaychangethelevelofvacuuminsidethemicroscope.Ifthevacuumchangesradicallyandabnormallywhenyoustarttodosomething,STOPandreverseyouractions,waitforthevacuumtorecoveranddeterminewhythereisaproblem.ThiswillusuallyinvolveconsultingGabriellaChapman,JohnLynchorRonDoole.Donothesitatetocontactoneofthemifyouareunsureofwhattodoinanyparticularsituation.
StartingUp
∙CheckvacuumItshouldbelessthan10x10-5Paontheion-pumppowersupplybehindthemicroscope.
∙Ifyouwishtousetheanti–contaminationdevicepleaseseeGabriellaChapmanorJohnLynchforinstruction.Atpresentthemicroscoperequiresamodificationbeforeitcanbeused.
∙Loadyourspecimen,
-Putonsomegloves.
Tolimitunwantedcontaminantsinthespecimenenvironmentofthemicroscope,alwaysweargloveswhenhandlingthespecimenholders,donottouchanypartofthemetalrodoftheholderwithyourbarehands.Althoughonlypartoftherodactuallyentersthevacuumofthemicroscope,greaseandothercontaminantsfromyourhands(ifyoudonotweargloves)maybetransferredalongthespecimenrodtothesectionthatisinsertedintothevacuumsystem.
-ZerotheX,Ytilts.ZerotheX,Yspecimenposition.Lockgoniometer.Makesurethefilamentisoffandalldetectorsarefullyretracted.
-Removethespecimenholderfromthemicroscope.Pulltheholderoutuntilitstops,rotateanticlockwiseandeaseout.
-Turnthesampleholderupsidedownandtapgentlyonthebackend(awayfromthesample)tomakesureyoursamplewillnotfalloutinthemicroscope.
-Alwaysinspecttheo-ringbeforeinsertingtheholderintothemicroscope,astheytendtopickuphairs,dust,etc.Wipewithaglovedfinger.Donotgreasethespecimenholdero-ringswithoutfirstconsultingGabriellaChapmanorJohnLynch.
-Insertthespecimenholderstraightintothemicroscopewithoutturningit.(Ifyouturntheholderyouwillallowairintothecolumn).Itshouldtriggeramicroswitchthatstartsthepumpdowncycle.Youmayhavetopushtheholderagainstthemicroswitchtotriggerit(don’tturntheholder!
!
).
-Pumpforaminimumofthreecyclesandamaximumoffivebeforeinserting.YouMUSTwaitforthreecycles!
Donotinsertsampleholderiftheredlightison.Thesecyclesmaytakelongerifthefilmhasjustbeenchanged.Inserttherodbyrotatingclockwiseandallowthevacuumtopulltheholderin-donotreleaseituntilitisallthewayintothemicroscope.
-Ifthevacuumdoesnotrecoverwithinashorttime,checktoseeifthefilmwaschangedinthelasthour.Ifnot,theholdero-ringmaybedirty,removetheholderandcleantheo-ringwithalintfreewipe.
∙TurninguptheHT
BeforeswitchingontheHTcheckthevacuumislessthan10x10-5Pa.
StarttheHTat160kV.
TheHTmaybechangedwiththewhiterockerswitch,whichisabovetheHTon/offswitch.TheamountbywhichtheHTchangeseachtimeyouclicktherockerswitchmaybesetonthekeyboard.Type‘HT’andthentherequiredstepsize(e.g.05)onthekeyboard.Thesizeisdisplayedonthebottomlineofthedisplayasyoutype.AfterturningtheHTonat160kV,setthestepsizeto5kVandbringthevoltageupto190kV.Waitacoupleofsecondsaftereach5kVclicktoensurethevacuumreadingontheion-gaugedoesnotrise.At190kVchangethestepsizeto1kV,andcontinuetoraisethevoltageto200kV,checkingthatthevacuumlevelinthecolumndoesnotchangesignificantly.Ifthevacuumdoeschange,waitforittorecoverbeforeincreasingthevoltagefurther.Ifthereisaverylargechangeinthevacuumlevelorifthereisadischargeinthegunseekhelp.
Thedarkcurrentshouldread~103andnomorethan105at200kV.Ifitreads000,theHTisoff.
∙Filamentheating:
Starttoheatthefilamentwhenthevacuumislessthan10x10-5Pa.
IncreasethefilamentheatingtosaturationSLOWLYtakingabout2minutesinall.
Generallythereisstillsomedetailinthefilamentevenwhenitissaturated.Thestopissetattheusualsaturationpointforthecurrentfilament.Itisusuallybetween109-114µA.(emissioncurrentat~10µAabovedarkcurrentfromcoldandafter30minsto1hr5-8µAabovedarkcurrent).
Ifyouhavereachedthestopandthereisnobeamonthescreen,seethenextsection(“AligningtheMicroscopeforGeneralUse”,step0.)tofindthebeam.
DONOTCHANGETHEBIAS–seekhelpifyouthinkitneedsresetting.
Ifthebrightnessofyourimageseemslow(lookataholeinyourspecimentobesurethebrightnessproblemisnotreallyjustaspecimenthicknessproblem)oriftheexposuretimesforyourpicturesaretoolong,pleaseaskforadviceonhowbesttoproceed.
-Alwaysturnthefilamentdowntozerobeforeremovingthespecimenfromthemicroscope.
-Turningdownthefilamentshouldbeaslowandcontinuousprocess,takingabout30-60seconds..Itisnotnecessarytotakeaslongaswheninitiallyheating.
Shuttingdown
∙Withdrawtheobjectiveandselectedareaapertures.
∙Leavelargestcondenserapertureinserted–levertotheleft
∙TEMimagemode.Spotsize2L.Mag15kx.Spreadbeamtojustfillthelargescreen.
∙X,Ytilttozero.Lockgoniometer.
∙X,Ypositiontozero.
∙Turnthefilamenttozerobeforeremovingthespecimenfromthemicroscope.
Turningdownthefilamentshouldbeaslowandcontinuousprocess,takingabout30-60seconds.Itisnotnecessarytotakeaslongaswheninitiallyheating.
∙TurntheHToff.
∙Turnthemagnificationbackupto100kx.
∙Removeyourspecimen–pullthesampleholdertothestop,rotatecounterclockwise,easeoutwiththumb.
∙Inserttheemptyspecimenrodintothemicroscope.
∙Changeexposedplatesifyouusedanyfilm.
Itisbettertodothisafterthespecimenrodisbackinthemicroscope,otherwisethevacuumwilltakemuchlongertopumpdown.
∙TurnoffthepanellightsandCRTscreen.
∙Signthelogbook.
∙Donotturnoffthemicroscope.
AligningtheMicroscopeforGeneralUse
0.Findthebeam
∙Thelastusershouldhaveleftthemicroscopewiththebeamjustfillingthescreenatamagnificationof5-20kX.Ifyoucan’tseeanybeam,themostlikelyreasonisthatyoursampleisintheway–trymovingitaround.DONOTmoveapertures,guntilt/shiftorbeamshifttofindthebeam!
∙Ifyoucan’tseethebeam,trythefollowing(approximatelyinorder):
∙Checkthatthefilamentbrightcurrenthasreachedthenormalvalue(~109-114).Thefilamentheatershouldbeatthestop.DONOTMOVEthestopposition.
∙Checkthespotsizeis2L.
∙Decreasethemagnificationandspreadthebeam.
∙Checkthattheobjectiveandselectedareaaperturesareout.DON’TMOVEtheXandYknobs!
∙Ifyouknowyoushouldhaveaholeapproximatelyinthecentreofyourspecimenoryouhaveagrid,movethespecimenalittleuntilyouseethehole.Watchthespecimenpositiononthemicroscopecomputerscreen.
∙Gotolowmag.modeandspreadthebeam.
∙Moveyoursampletofindthehole.
∙The2000FXhasatwo-sampleholder.Ifsomeonehasusedthisbeforeyou,itmaybesetatposition1or2.Forasinglespecimenholder,thepositionshouldbeinthemiddle.Theadjustmentisontheleftsideofthemicroscopecolumn.Itisaknurledwheelwithapositionmarker.
∙Ifyoustillcan’tseethebeam,goandgethelp.
1.FilamentAlignment
∙Beamonscreen,Magnificationat20Kx,SpotSizeat2L(Page1ofmicroscopedisplay).
∙Chooseanappropriatecondenseraperture.Withthelevertotheleftthesizesare200,120and70μm.
∙AdjusttheGunAlignTiltformaximumbrightness.(rightdrawer)
∙BringBrightnesstocrossoverandcentrethebeamwithGunAlign.ShiftX,Y.(rightdrawer)
∙AdjustGunAlign.Tiltformaximumbrightness.
2.Gun/CondenserAlignment
∙ChangeSpotSizeto4L.(spotsizetoggleswitchonleftpanel)
∙BringBrightnesstocrossoverandcentrebeamwithBeamShiftsX,Y.
∙SwitchSpotSizebackto2L.
∙BringBrightnesstocrossoverandcentrethebeamwithGunAlignmentShiftsX,Y.
∙Repeatuntilbeamremainscentredforbothspotsizes.
∙RecentreGunTiltasin1above(tiltformax.brightness).
CentrebeamfromnowonwithBeamShifts,NOTGunAlignmentShifts
3.CondenserApertureCentring
∙CentrebeamonscreenatcrossoverwithBeamShiftsX,Y.
∙Watchforbeam‘swing’whenspreadingthebeamwithBrightnesseithersideofcrossover.
∙Ifbeamswingsawayfromcentrewhenspread,correctbycentringthecondenseraperture.
4.Condenserstigmation
∙Correctcondenserlensastigmatismwithcondenserstigmator(buttonleftpanel;defX,Y)
5.OptimumObjectiveFocus./AdjustZAxis(EucentricCorrection)
CoarseAdjustment:
∙SetOBJLenscurrent(readonPage4)intheregionof7.00to7.05at200kV(5.21at120kV)usingObjectivefocusknob(rightpanel).
∙LocatespecimenandcentreafeatureataMagnificationof15Kxorless.
∙FocustheimageusingtheZheightadjustknob.(upnearthespecimen