2024年4月1日发(作者：夏骥)

2017·27·

2-6MeasurementsofDistancebetweenUltra-thinFoilsoftwoTOF

DetectorsunderUltra-highVacuumCondition

∗

YanXinliang,ChenRuijiu,MaHui,YuanJiandong,WangShaoming,CaiGuozhu,ZhangMin,LuZiwei,

FuChaoyi,ZhouXu,WangMengandZhangYuhu

ThedistancebetweentwoidenticalTime-Of-Flight(TOF)detectors,whichareinstalledinside10

−11

mbar

vacummbeampipeinthestraightsectionofthestorageringCSRe,ismeasuredbyalaserrange-finderLeicaNova

MS60MultiStation

[1]

.Theobjectsofthemeasurementarethetwocarbon-foilsofthedetectorswiththeircentres

meterandthicknessofthefoilsare40mmand≈90nmrespectively.

SchematicviewandpictureoftheTOF-detector

[2]

-

detectorsaremoveabled

laserbeamfromthemultistationareshonedirectlythroughthequartzvacuumwindowintothevacuumbeampipe

andthereflectedlightfromthecarbon-foilwillpassthequartzwindowsagainonthewaybacktothemultistation.

Thetimeofflightofthereflectedlightpulsecanbeusedtodeterminethedistancefromthecarbonfoiltothe

erspotofMS60multistationisabout5mm×elength

surementwithoutreflectorssuchasinthisexperiment,thepulsedurationis1.5ns

andthepulserepetitionfrequencyis2MHzforscanmodeand4MHzforpointmode.

Fig.1(coloronline)Left:SchematicviewofdistancemeasurementsofTOF-detectorusingalaserrange-fier

tesiancoordinatesystemissetbytheMS60multistationbeforemeasurement

andtheang:ApictureofTOF-

:TheslantrangeofthedownstreamTOF-detectorwhenthelaserbeamdirectionisfixed,seethemaintext.

Theprecisionandreliabilityofthemeasurementswerecheckedbymonitoringthedistanceofthedown-stream

ultisshownintherightpanel

ncirclesareresultswhenthedetectorwasstationaryandthelaserbeamwasonthecenterof

ultsshowedthatthecarbonfoildistancecanbemeasuredwithastandarddeviationofless

losecirclesareresultswhenthedetectorweremovingbackwardandforwardinx-direction

dingring,mounting

baseboardandthecarbon-foilofthedetectorweremeasuredatslantrangesofabout23757.9,23762.1and23773.1

mm,ativedistancesbetweendifferentpartsofthedetectorreflectthereliabilityofthelaser

range-finderMS60multistation.

The3DpositionsofthetwocarbonfoilswerethenscannedwhiletheTOF-detectorswerekeptstationaryduring

rtodothis,thecentresofthecarbon-foilsof

thetwodetectorswerefirstlyalignedtotheionbeamlineandaCartesiancoordinatesystemwasset(X=Z=0)

heup-streamdetectorwasscanned,itwill

benningstepinthe

ghtheDAQrateisfasterinscanmode,the

standarddeviationofthemeasurementisstillsmallerthan0.2mmbycheckingtheslantrangesofasmallflatarea

ofabout3mm×nningresultsofthetwo

resomeareasinultra-thinfoilsthatnodata

hereflectedlaserpulsesfromthoseareaswastooweaktobedetectedbythe

heless,thepositionsofthecarbonfoilsanditsholdingringareclearlyseeninthecolor-coded

imumsurfaceroughnessoftheup-streamanddown-streamcarbonfoilsmeasuredto

∗Foundationitem:NationalNaturalSciencefoundationofChina(11605248,11605252)

·28·2017

be1.3mmand0.6mm,ngangleof2.3

◦

outthatthecentresofthetwofoilsarenotinthesamealtitude:thedown-streamfoilisabout6.7mmhigher

tion,theoverlappedareainthexz-planebetweenthetwofoilsislessthan20

mm×20mm,mainlyrestrictedbythesmalleravailableareathatcanbemeasuredontheultra-thincarbonfoilof

heydirection,thepoint-to-pointdistances(∆y)ofthetwocarbonfoils

haveameanvalueof18033.85mmandarerangingfrom18032.5mmto18035.0mm,seetherightpanelofFig.

iationshaveastandarddeviationof0.6mmandthemaincontributionofthevariationscomesfromthe

surfaceroughnessofthefoils,especiallytheup-streamcarbonfoil.

Fig.2(coloronline)Leftandmiddlepanels:the3Dpositionsoftwoultra-thincarbonfoilsofthetwoTOFdetectorsinside

tesiancoordinatesystemisdefinedbytheMS60multistationatthebeginningofthescanning.

Theexperimentalresultsarerenting

ringreareasinultra-thinfoilsthatno

anel:Thepoint-to-pointdistance(∆y)betweenthetwocarbon-foils.

Theabsolutedistancebetweenthetwoultra-thincarbonfoilsinsideavacuumpipehasbeenmeasuredtobe

18033.85mmwithavariationof±1.25mmwithinameasurableoverlappedareaof20mm×n

contributionofthevariationscomesfromthesurfaceroughnessofthetwofoilswhichisonthelevelof1mm.

Becauseofnon-zerobetafunctionattheTOFdetectorsandnon-zeroemittanceofthestoredbeaminCSRe,the

passingpositionsatthecarbonfoilsofacircultingionwillberandomlydistributedrevolutionbyrevolutiondue

=1mmmeansarelativeuncertaintyofdl/l<5.5×10

−5

for

theflcertaintyoftheflightpath

isfivetimestoolargefortheprecisionneededforin-ringvelocitymeasurementsatCSRe

[3]

.

Concerningthefutureimprovements,y,theattitudesof

thetwocarbon-foilshaveabout6mmdifferencewhichwilllimittheacceptanceoftheringwhentheTOFdetectors

ly,thetiltinganglebetweenthetwofoilsisabout2.3

◦

whichmeanstransversedistance

of20mmonthecarbonfoilswillintroduce20mm×tan(2.3

◦

)=0.8mmdifferencestotheflightpathofstoredions

lyadjustmentsofthehightand

y,thesurfaceroughnessofthetwoultra-thincarbonfoilsareonthe

levelof1mm,newcarbonfoilswithmoreflrange-finderwithsufficientaccuracy,like

MS60multistation,ral,laserrange-findersareuseful

positionmonitoringtoolsforanyfragileobjectsinplacewhereitisdifficulttoreach,suchasTOF-detectorsinside

esignoffuturestorageringatHIAFfacility

[4]

,twoTOF-detectorsequippedwithultra-thin

carbonfoilsofevenlargerdiametersareforeseentobeinstalledinoneofthestraightsectionofthering

[5]

.It

isthereforesuggestedtopreparequartzvacuumwindowsinthebeam-linetoallowdiagnosislaserbeamstopass

hang,uandtechnicalsupports

fromLeicaGeosystemscompanyaregreatlyacknowledged.

References

[1]

[2]

[3]

[4]

[5]

/products/total-stations/multistation/leica-nova-ms60.

,,,etal.,.A,624(2010)109.

,,,etal.,.B,376(2016)311.

,,,etal.,.B,317(2013)179.

,,,etal.,.A,881(2018)27.

2024年4月1日发(作者：夏骥)

2017·27·

2-6MeasurementsofDistancebetweenUltra-thinFoilsoftwoTOF

DetectorsunderUltra-highVacuumCondition

∗

YanXinliang,ChenRuijiu,MaHui,YuanJiandong,WangShaoming,CaiGuozhu,ZhangMin,LuZiwei,

FuChaoyi,ZhouXu,WangMengandZhangYuhu

ThedistancebetweentwoidenticalTime-Of-Flight(TOF)detectors,whichareinstalledinside10

−11

mbar

vacummbeampipeinthestraightsectionofthestorageringCSRe,ismeasuredbyalaserrange-finderLeicaNova

MS60MultiStation

[1]

.Theobjectsofthemeasurementarethetwocarbon-foilsofthedetectorswiththeircentres

meterandthicknessofthefoilsare40mmand≈90nmrespectively.

SchematicviewandpictureoftheTOF-detector

[2]

-

detectorsaremoveabled

laserbeamfromthemultistationareshonedirectlythroughthequartzvacuumwindowintothevacuumbeampipe

andthereflectedlightfromthecarbon-foilwillpassthequartzwindowsagainonthewaybacktothemultistation.

Thetimeofflightofthereflectedlightpulsecanbeusedtodeterminethedistancefromthecarbonfoiltothe

erspotofMS60multistationisabout5mm×elength

surementwithoutreflectorssuchasinthisexperiment,thepulsedurationis1.5ns

andthepulserepetitionfrequencyis2MHzforscanmodeand4MHzforpointmode.

Fig.1(coloronline)Left:SchematicviewofdistancemeasurementsofTOF-detectorusingalaserrange-fier

tesiancoordinatesystemissetbytheMS60multistationbeforemeasurement

andtheang:ApictureofTOF-

:TheslantrangeofthedownstreamTOF-detectorwhenthelaserbeamdirectionisfixed,seethemaintext.

Theprecisionandreliabilityofthemeasurementswerecheckedbymonitoringthedistanceofthedown-stream

ultisshownintherightpanel

ncirclesareresultswhenthedetectorwasstationaryandthelaserbeamwasonthecenterof

ultsshowedthatthecarbonfoildistancecanbemeasuredwithastandarddeviationofless

losecirclesareresultswhenthedetectorweremovingbackwardandforwardinx-direction

dingring,mounting

baseboardandthecarbon-foilofthedetectorweremeasuredatslantrangesofabout23757.9,23762.1and23773.1

mm,ativedistancesbetweendifferentpartsofthedetectorreflectthereliabilityofthelaser

range-finderMS60multistation.

The3DpositionsofthetwocarbonfoilswerethenscannedwhiletheTOF-detectorswerekeptstationaryduring

rtodothis,thecentresofthecarbon-foilsof

thetwodetectorswerefirstlyalignedtotheionbeamlineandaCartesiancoordinatesystemwasset(X=Z=0)

heup-streamdetectorwasscanned,itwill

benningstepinthe

ghtheDAQrateisfasterinscanmode,the

standarddeviationofthemeasurementisstillsmallerthan0.2mmbycheckingtheslantrangesofasmallflatarea

ofabout3mm×nningresultsofthetwo

resomeareasinultra-thinfoilsthatnodata

hereflectedlaserpulsesfromthoseareaswastooweaktobedetectedbythe

heless,thepositionsofthecarbonfoilsanditsholdingringareclearlyseeninthecolor-coded

imumsurfaceroughnessoftheup-streamanddown-streamcarbonfoilsmeasuredto

∗Foundationitem:NationalNaturalSciencefoundationofChina(11605248,11605252)

·28·2017

be1.3mmand0.6mm,ngangleof2.3

◦

outthatthecentresofthetwofoilsarenotinthesamealtitude:thedown-streamfoilisabout6.7mmhigher

tion,theoverlappedareainthexz-planebetweenthetwofoilsislessthan20

mm×20mm,mainlyrestrictedbythesmalleravailableareathatcanbemeasuredontheultra-thincarbonfoilof

heydirection,thepoint-to-pointdistances(∆y)ofthetwocarbonfoils

haveameanvalueof18033.85mmandarerangingfrom18032.5mmto18035.0mm,seetherightpanelofFig.

iationshaveastandarddeviationof0.6mmandthemaincontributionofthevariationscomesfromthe

surfaceroughnessofthefoils,especiallytheup-streamcarbonfoil.

Fig.2(coloronline)Leftandmiddlepanels:the3Dpositionsoftwoultra-thincarbonfoilsofthetwoTOFdetectorsinside

tesiancoordinatesystemisdefinedbytheMS60multistationatthebeginningofthescanning.

Theexperimentalresultsarerenting

ringreareasinultra-thinfoilsthatno

anel:Thepoint-to-pointdistance(∆y)betweenthetwocarbon-foils.

Theabsolutedistancebetweenthetwoultra-thincarbonfoilsinsideavacuumpipehasbeenmeasuredtobe

18033.85mmwithavariationof±1.25mmwithinameasurableoverlappedareaof20mm×n

contributionofthevariationscomesfromthesurfaceroughnessofthetwofoilswhichisonthelevelof1mm.

Becauseofnon-zerobetafunctionattheTOFdetectorsandnon-zeroemittanceofthestoredbeaminCSRe,the

passingpositionsatthecarbonfoilsofacircultingionwillberandomlydistributedrevolutionbyrevolutiondue

=1mmmeansarelativeuncertaintyofdl/l<5.5×10

−5

for

theflcertaintyoftheflightpath

isfivetimestoolargefortheprecisionneededforin-ringvelocitymeasurementsatCSRe

[3]

.

Concerningthefutureimprovements,y,theattitudesof

thetwocarbon-foilshaveabout6mmdifferencewhichwilllimittheacceptanceoftheringwhentheTOFdetectors

ly,thetiltinganglebetweenthetwofoilsisabout2.3

◦

whichmeanstransversedistance

of20mmonthecarbonfoilswillintroduce20mm×tan(2.3

◦

)=0.8mmdifferencestotheflightpathofstoredions

lyadjustmentsofthehightand

y,thesurfaceroughnessofthetwoultra-thincarbonfoilsareonthe

levelof1mm,newcarbonfoilswithmoreflrange-finderwithsufficientaccuracy,like

MS60multistation,ral,laserrange-findersareuseful

positionmonitoringtoolsforanyfragileobjectsinplacewhereitisdifficulttoreach,suchasTOF-detectorsinside

esignoffuturestorageringatHIAFfacility

[4]

,twoTOF-detectorsequippedwithultra-thin

carbonfoilsofevenlargerdiametersareforeseentobeinstalledinoneofthestraightsectionofthering

[5]

.It

isthereforesuggestedtopreparequartzvacuumwindowsinthebeam-linetoallowdiagnosislaserbeamstopass

hang,uandtechnicalsupports

fromLeicaGeosystemscompanyaregreatlyacknowledged.

References

[1]

[2]

[3]

[4]

[5]

/products/total-stations/multistation/leica-nova-ms60.

,,,etal.,.A,624(2010)109.

,,,etal.,.B,376(2016)311.

,,,etal.,.B,317(2013)179.

,,,etal.,.A,881(2018)27.