commandopeneuler

KMC2-diffractometry(version2006_09_10)6-circlediffractometer(HUBER)psi-geometry4-circlediffractometerwithomega/2theta-axisvertically,minimumstepsize:2.
5x10-4degree.
OpenEuleriancradle(5kgload)equipedwithanxyz-stage.
Twoadditionalaxes,muandnu(minimumstepsize:2.
5x10-3)toallowfornon-coplanarscattering.
Amotorizedx-y-zstageismountedatthesamplestage.
Twosetsofmotorizedslitsandonemanuallyadjustableslitsetareusedtoshapethebeamandascollimationpathforthedetectorarm.
(beampropagatesiny-direction)Scintilationdetector:CyberstarX1000byOxfordDanfysikisusedforhigh-resolutionmeasurements.
Detectorparameterscanbechangedfromthecomputer.
2D-detector:gasfilledwiredetectorbyBRUKERAXSactivearea:115mmindiameterenergyrange:3-15keVspatialresolution:150mmaximaloverallintensity:40000c/smaximallocalintensity:300c/s/pixelin512x512modeThetotalintensitycanbereadontherate-o-metermountedinthe19"rack.
Ionisationchamber:ICPluswith50mmactivelengthincl.
"piggyback".
electronicmoduleforminimizationofnoiseTherearecommandstochangethevoltageandtherangeoftheionisationchamber,buttheyarenotnecessaryforsimplemeasurements.
High-temperaturevacuumchamberAsingle-samplediffractomtrycanbemountedonthegoniometerinsteadofthex-ytranslationstage.
Verticaltranslationandallgoniometeraxesareavailable,but,duetodifferentoutletsonthechamber,inlimitedrange.
Chamberisabletoheatupto1000°C.
AxesnamesHuber:Sampleaxes:mu,eta,chi,phiDetectoraxes:nu,delSlits:JJX-rayslitsmoveeachknifeindependently.
Therearetwoslitsystems,SDandSF,sothemotornamesare:SF_t,SF_b,SF_l,andSF_rfortop,bottom,left,andrightknifeoftheSFslitsrespectively,andSD_t,SD_b,SD_l,andSD_rforSDslits.
Dependingonthedetectorandconfigurationused,SDandSFhavedifferentusages:1)1Ddetector:SFisthebeamdefinitionslit,SDistogetherwithSH(themanualHuberslit)usedasthedetectorcollimationslit.
2)2Ddetector:SFisthebeamdefinitionslit.
3)2Ddetector,diffusescatteringatsmallangles:SDisthebeamdefinitionslit,SFistheguardslit.
Exceptforthe"mv"commandstomoveeachsingleedge,therearespecialcommandsforslits:SF_openX,SD_openX–openstheslitshorizontallyandverticallyXmilimeter.
beam_find_det_SF,beam_find_mon_SF,beam_find_det_SD,beam_find_mon_SDperformsthescanstofindthebeamposition,movesallslitstothecenterofthebeam,resetsthemto0,andopensthem0.
1x0.
1mm.
The"det"and"mon"commandsusethedetectorormonitortoestimatethecenterofthebeam.
beam_profile_SD,beam_profile_SFperformtwoscansresultinginhorizontalandverticalprofileofthebeamattheslitposition.
Attenuator:Thereisanattenuatorwheelintheprimarybeam.
Withthecommand:attXonecaninsertXmthickCufoilintheprimarybeam.
Availablefoilsare:0(nofoil),25,50,100,150,200,250,300,500m.
50mCuinthebeamhas10%transmissionfor8keVbeam.
Toaskwhichfilteriscurrentlyinthebeamusethecommand:att_getThemotormovingthefilterisnamed"att_w",andiswritteninspecfilesforeverymeasurement.
Theattenuatormotorhasnolimit-orhome-swithes.
Atthebeginningofthemeasurement(withthemainshutterclosed)doatt0andthanmanuallyturnthewheeluntilthefilter8(0muthickness)isinthebeam.
SpeccommandsStartingthemeasurement:newfileYYYY_MM_DD_samplename.
specopensthenewfileandstartswritingtheresultsinit.
Doitforeverynewsample.
Theformatofthefilenameisfree,buttheproposedformathelpstofindthefilesandsortthemwithoutopening.
MovingmotorsThebasiccommandformovingthemotorsis"mv".
Ittellsspectomovethespecifiedaxistospecifiedposition.
mvmotorposition–movesthemotortoabsolutepositionmvrmotordistance–movesthemotorspecifieddistancerelativetocurrentpositionumv,umvr–thesamebutshowctheupdatedcoordinateonthescreenwhilemovinghomemotor–startsthehome-searchingprocedure.
Toaskforthepositionofmotors,oncantypewaandthepositionsofallmotorsareprintedtothecommandinterface.
Countingtoperformcountingfor10secondstype:ct10tocount1seconddo:ctScansSimplescanwithonemotoruseascanmacro:ascanmotorstartendstepstimee.
g.
:ascandel2030101movesmotordeltopositions20,21.
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29,30(10steps,11measurements)andcounts1secondateachposition.
Motorstaysattheendpositionafterscan.
Tomovetwomotorssynchronouslydoa2scanmotor1start1end1motor2start2end2stepstimeInsteadoftheabsolutecoordinatesforscan,itispossibletogivethepositionsrelativetocurrentpositionofaxes.
Insteadofascanusedscan.
Toperformatheta-2thetascanaroundaselectedpeak,optimizetheintensitybymovingallmotorsandthendo:d2scandel-11eta-0.
50.
510001MeshMeshisaspecialformofscanwheretwomotorsaremovedindependentlytoscanaregionintwodimensions.
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2DdetectorTosetupspecfortheuseofthe2Ddetector,startthe'slavetospec'programatthewindowscomputer(ifitisnotrunning)andtypetothespeccommandprompt:GADDS_onYouwillbepromptedforthewavelengthandthedistancebetweenthesampleandthedetector.
Thesevaluesareusedlaterasthestartvaluesforthecalibration,theydon'thavetobeaccurate.
(butthemoretheyareaccurate,thesimplerthecalibration)Tostoptheacquisitionoftheareaframeswrite:GADDS_offWheninGADDSmodus,allscansautomaticallyacquirea2Dimageforeverysinglecountcommandinthescan.
Thecommand"ct"isnotchanged,i.
e.
Itonlywritesthetotalnumberofphotonsinthedetectortotheterminalline.
Noimagesaresaved.
Totakeonlyoneframeusethecommand:acquireXThisisgoingtostartascanwithonlyonepointand"X"secondsacquisitiontimeandsaveanimagetotheharddisk.
Thecompleteprocedureoftakingthecorrectionandbackgroundfilesfortheareadetectorisdescribedelsewhere(BrukerAXSmanual).
GIDmeasurementGIDgeometryisrealizedinthewaythatthescatteringdefractsthebeaminverticaldirection.
Thisgeometrydoesnotrequirethepolarizationcorrectionforthescatteredbeam.
Sampleispositionedvertically(surfacenormalishorizontal)atthegoniometerbymovingchito0.
Axesnuandmuareusedtosettheαiandαf,thegrazingincidentandexitphotonangle.
Sincephiandetaarecolinearinthisgeometry,thereisapossibilitytorotatephiforlargeangles,butscanningandmeasurementsshouldbeperformedusingetaduetoit'sprecision.
Foreasierevaluationandunderstandingofdata,etashouldbedel/2.
SampleismountedonthegoniometerheadusingAluminumplates.
Samplecanbefixedtotheplateusingwaxordouble-sidedadhesivetape.
Movemotorstofollowingpositions:munuchietadelphi008000Switchthelaseronatthecontrolpaneloutsideofthehutch.
Bymovingthelaserassureyourselftheatthelaserishittingthesample.
Closetheleftdoorofthehutchandmarkthepositionofthelaserspotonapeaceofpaper.
inspectypemvphi180.
Thiswouldproducethesecondspot.
Markit,drawthelinebetweentwopoints,andfindthemiddle.
Repeatthisprocedureforphivaluesof90and270.
Correctthepositionofthelaserspotintothemiddleofthecrossbyadjustingthegoniometerhead.
Domvphi0,andifthelaserspotdoesnotmove,thesamplesurfacenormalisparaleltotheaxisofphirotation.
Switchthelaseroff.
WARNING:Trynottolookatthesamplewhenthelaserisswitchedon.
Althoughthelaserintensityisreallylowlookingdirectlyinthelaser(orinthebeamreflectedbythesample)canseriouslydamageyoureyes.
Ifyoukeepallaxesatvaluesfromthetable,andlefthutchdoorisclosedatalltimeswhenthelaserisswitchedon,you'reprobablysafe.
mu,nu,αi,andαfItisnotstraight-forwardtouseapsicgoniometerforGIDscattering.
psicanglesaredifferentthanthe'six-circlesurfacediffractometer'.
Althoughalldegreesoffreedomareallowed,Thedetectorarmcoordinatesnuanddelarenotequivalenttoαfand2Θ.
Incidentanglesaresimple:=i.
Exitsideismuchmorecomplicated.
nu=αi+αfisOKonlyinreflectometry,orinapproximationforsmalldeltaangle.
Tocalculatethegeometryfrommotorpositionsuse:sinf=cossintan2=tancosAndtocalculatethemotorpositionsfromknowngeometry:sin=sin2cosftan=cos2cosfsinicosisinfcos2cosicosfsinisinf2Θistheprojectionofthescatteringangletothesurface,αiandαfareincidentandexitgrazingincidenceangles.
Becarefulfordelangleshigherthan90°!
!
Adjustingthesamplesurfaceinthebeam.
Therearedifferentproceduresdependingontheorientationofthesampleandonthesurfacepropertiesofthesample,butsincetheyallincludethesameelements,they'llallbedescribedhere.
1)Outenoughattenuatorsothedetectorcansurvivetheprimarybeam.
Itisgoodtosetthehighervalueandthengraduallyremovefilterifnecessary.
2)removethesamplefromthebeambytypingumvrz-2.
Thisisgoingtomovethesample2mmoutofthebeam.
3)dorelativescansinnuanddelandmovenuanddelintothepositionwheremaximalintensitywasmeasured.
Detectorissetnow.
Thisstepisnotnecessaryifyou'reusingtheareadetector.
Theequivalentactionisperformedbysavingapictureoftheprimaybeam,whichislaterusedtoestimatethepositionofthedetectorcenter.
4)movethesampleintothebeamuntilonlyhalfoftheintensityismeasured.
Sampleshadowshalfofthebeamnow.
Dothisbytypingmvrz0.
5untilthebeamvanishes(lookattherateometerorperformactaftereverymovement).
Whennearthepositiondodscanz-11201andmovemotorztothepositionwithmaximalintensity.
5)Tobesurethatthesampleisparalleltothebeamdoarocking-curvescanandmovetheaxisinmaximum.
Ifthesamplenormalispointedtotheroof(standardsymmetricaldiffractometry)thenyouhavetoscaneta,ifinGIDgeometry,you'llhavetoscanmu.
6)repeat4and5ifnecessary.
7)Ifthesamplesarehighlyreflecting,thisproceduremayleadtoanerror.
Ifthesamplesdonotreflect,thantheprocedureisover,andthesampleisaligned.
Setthecorrespondinganglesto0.
Points8to10areonlyforreflectingsamples.
8)movedetectortoananglewhichislargerthanthedoubleangleoftotalexternalreflection,e.
g.
to1deg.
Ifyoudidrockingoptimizationwitheta,thanyou'llhavetomovedelnow,ifyouoptimizedmuin5)thanyou'llhavetousenu.
9)Movethesampletothehalfofthisangle.
Performtherockingcurveandmovethesampleangletothepositionwherethemaximumwasdetected.
Setthesampleangletothehalfofthedetectorangle.
10)Steps8-9aresomewhatcomplicatedwhenusingtheareadetector.
Onehastoestimateangleresolutionofthedetectorandmonitorthepositionofthereflectedbeam.
Leavethistoexperts.
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WritinginLogbookAlthoughmostmeasurementparametersareautomaticallysavedbythecontrollerprogram,therearesomethingswhichneedtobewritteninthelogbook.
Thepreferredwaytowritethemeasurementdiaryistowriteinthebeamlinelogbook,userscangetaphoto-copyofthediary.
Thingswhicharenormallywritteninthelogbook:Whenstartingtheexperimentorwhenchangingthesetupitisnecessarytodescribetheexperiment.
Thebeamlinecanbeusedtoperformseveraldifferenttypesofexperiment,soitisnecessarytodeclarewhichexperimentareweperforming(XRD,powderdiffractometry,GID,GISAXS,constantincidentangle,constantexitangle,areweusingcapillariesorgoniometerhead,istheareadetectorgoingtobeused,whichslitsareusedforcollimation.
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Anicedrawingorprintedphotoisgood,especiallyiftheexperimentshouldberepeatedafterfewmonths.
Ashortdescriptionofthesystemwhichisgoingtobemeasuredisalsohelpful.
Ashortnoteisenough.
Examples:–Si-(001)-wafer,GIDon220reflection,scanningforsatelitepeaks.
–TiHpowderattemperaturesupto700°Cinairandinvacuum,expectedpatterns:TiH2,α-Ti,β-Ti,differentoxidesAteverynewfilecommand,orwhenreplacingthesample,ashortdescriptionofthesampleshouldbewritteninthebook.
Thisistheonlywaytocorrelatetheexperimentwiththesample.
Ifallsamplesareequivalent,asamplenumberwouldbeenough.
Ifthereareambiguitiesinthewaythesamplecanbemounted,themountingshouldbealsodescribed.
Thishelpsalotwhenwearerepeatingtheexperiment.
Sinceduringthemeasurementmanyunnecessaryscansareperformed,foreverysignificantscanascannumberandthedescriptionshouldbenoted.
Itisnotwrongtowritetheactualcommand,ifwearegoingtorepeatthisscanfornextsample.
Example:Scan2–sampleheightadjustment,sampleheightz=1.
43scan25–d2scandel-11eta-0.
50.
51001-theta-2thetascanaround002scan26–backgroundforscan25ThereareparameterswhichareNOTsaved.
Theseparametersaredifferentfordifferentexperiments.
Hereonlyfewexamples:–Highprecisiondiffractometry:Therearethreepairsofslitsinthebeamline,twoofthemaremotorized,oneisnot.
Ifthemanualslitisused,itisnecessarytowriteeverysinglechangeinthelogbook.
–AreaDetector:whenusingtheareadetector,thedetectordistanceisveryimportantparameter.
Whenusingthepointdetector,distanceisimportantonlyifweareinterestedinthedeviceresolutionorinabsolutescatteredintensity.
Alldistancesbetweensampleandslitsandbetweensampleanddetectorshouldbewritteninthelogbook.
–Hightemperaturechamber:Onlyonethermoelementisusedbythecontrollerandwritteninthefile.
Allotherparametersarenotmonitoredbythecomputer.
Themostimportantofthesevaluesisthesecondthermoelement.
Duringaheatingexperimentusersshouldcomparethesetwovaluesanddecideifboththermoelementsarestillconnectedtothestage.
Incaseoflargedifferencestheheatingshouldbeinterrupted.
Otherprocessvaluescanalsopointtomalfunctionofthedevice,ortoexplainwhyanexperimentdidn'twork(lowvacuumwouldexplaintheoxidepeaksinthescatteringcurve,highheaterresistancecanpointtomalfunctioningheater.
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Thesetofvalueswhichshouldbewrittendownatfewpointsduringthemeasurementinclude:time,temperaturesofallthermoelements,pressure,voltageandcurrentatthepowersupply.
–Wavelengthorenergyoftheprimarybeam.