计算机硬件开发.docx

计算机硬件开发.docx

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计算机硬件开发

AJava-baseddataacquisitionsystemfornuclearphysics  OriginalResearchArticle

NuclearInstrumentsandMethodsinPhysicsResearchSectionA:

Accelerators,Spectrometers,DetectorsandAssociatedEquipment

JamisaJava-baseduser-friendlydataacquisitionandanalysissystemdevelopedforCAMAC-basednuclearphysicsexperiments.Thesystemismenu-drivenandhasbeendesignedtominimizetheexpertiseneededtoperformtheessentialtasksnecessarytocollectandsortdata.Thefront-endhardwareisVMEbasedandincludesaMVME167runningVxWorks,whichisnetworkedtoaSunworkstation.Thesorting,display,andcontrolroutinesareallwritteninJava,andthefront-endcodeiswritteninC.WithaSparc5workstation,eventswith10parameters,15histograms,and10gatechecksthesystemcancollectandsortdatauptoeventratesof1kHz.Byonlysortingafractionoftheevents,butstoringallevents,itcanberunatthefront-endlimitof10kHz.Java'spromiseofplatformindependencehasbeenfoundtoberealistic,andJamhasbeenusedwithnomodificationstosortofflineonmultipleplatforms.Jamhasamodulardesignallowingittobeeasilymodified.Forexample,Jamhasaninterfacetoallowuserstowritetheirownfittingroutines.Thisarticlediscussesthesystem'sdesignandperformance,aswellassomeadvantagesanddisadvantagesofusingJava.

ArticleOutline

1.Introduction

2.Design

2.1.Userinterface

2.2.Onlinedataacquisitionandofflinesorting

2.3.Analysistools

2.4.Writingasortroutine

3.Systemdescription

3.1.Hardwarerequirements

3.2.Codefordataacquisition

4.Discussion

4.1.ThedisadvantagesofusingJam

4.2.TheadvantagesofusingJam

4.3.Summary

Acknowledgements

References

TheALICETPC,alarge3-dimensionaltrackingdevicewithfastreadoutforultra-highmultiplicityevents  

NuclearInstrumentsandMethodsinPhysicsResearchSectionA:

Accelerators,Spectrometers,DetectorsandAssociatedEquipment

Thedesign,construction,andcommissioningoftheALICETime-ProjectionChamber（TPC）isdescribed.Itisthemaindeviceforpatternrecognition,tracking,andidentificationofchargedparticlesintheALICEexperimentattheCERNLHC.TheTPCiscylindricalinshapewithavolumecloseto90 m3andisoperatedina0.5 Tsolenoidalmagneticfieldparalleltoitsaxis.

InthispaperwedescribeindetailthedesignconsiderationsforthisdetectorforoperationintheextrememultiplicityenvironmentofcentralPb–PbcollisionsatLHCenergy.Theimplementationoftheresultingrequirementsintohardware（fieldcage,read-outchambers,electronics）,infrastructure（gasandcoolingsystem,laser-calibrationsystem）,andsoftwareledtomanytechnicalinnovationswhicharedescribedalongwithapresentationofallthemajorcomponentsofthedetector,ascurrentlyrealized.Wealsoreportontheperformanceachievedaftercompletionofthefirstroundofstand-alonecalibrationrunsanddemonstrateresultsclosetothosespecifiedintheTPCTechnicalDesignReport.

ArticleOutline

1.Introduction

2.Fieldcage

2.1.Vessels

2.2.Centralelectrode

2.3.Rods

2.3.1.Resistorrods

2.3.2.High-voltagecablerod

2.3.3.Laserrods

2.3.4.Gasrods

2.4.Strips

2.5.Skirts

2.6.Endplates

2.7.I-bars

3.Readoutchambers

3.1.Designconsiderations

3.2.Mechanicalstructure

3.2.1.Wires

3.2.2.Wireplanes

3.2.3.Anode-wiregrid

3.2.4.Cathode-wiregrid

3.2.5.Gating-wiregrid

3.2.6.Coverandedgegeometry

3.2.7.Padplane,connectorsandflexiblecables

3.2.8.Padplanecapacitancemeasurements

3.2.9.Al-body

3.3.Testswithprototypechambers

3.3.1.Descriptionofproductionsteps

3.3.2.Qualityassuranceandtests

3.4.Chambermountingandpre-commissioning

4.Front-endelectronicsandreadout

4.1.Generalspecifications

4.1.1.Systemoverview

4.2.PASA

4.3.ALTRO

4.3.1.Circuitdescription

4.3.2.Physicalimplementation

4.4.Front-endcard（FEC）

4.4.1.Circuitdescription

4.4.2.Physicalimplementation

4.5.RCU

4.5.1.RCUmotherboard

4.5.2.DCSboard

4.6.Triggersubsystem

4.7.Radiationtolerance

4.7.1.SEU

4.7.2.SEL

4.8.Testingprocedure

5.Coolingandtemperaturestabilizationsystem

5.1.Overview

5.2.Thenecessityforuniformtemperatures

5.2.1.Heatloadandcomputationalfluiddynamicscalculations

5.3.Principleofunderpressurecooling

5.4.TPCcoolingplants

5.4.1.Coolingcircuits

5.5.Coolingstrategy

5.6.Commissioningofthecoolingsystem

5.6.1.Testwithmock-upsectors

5.6.2.Startupproceduresandoperation

5.6.3.Cavitationproblem

5.7.Temperaturemonitoringsystem

5.7.1.Temperatureprofileandhomogenization

6.Gasandgassystem

6.1.Gaschoice

6.1.1.Implicationsofthegaschoice

6.2.Descriptionofthegassystem

6.2.1.Configuration

6.2.2.On-detectordistribution

6.2.3.Filling

6.2.4.Running

6.2.5.Back-upsystem

6.2.6.Analysis

7.Lasersystem

7.1.Requirements

7.2.Systemoverview

7.3.Opticalsystem

7.3.1.UVlasers

7.3.2.Laserbeamtransportsystem

7.3.3.Micromirrorsandlaserrods

7.4.Laserbeamcharacteristicsandalignment

7.4.1.Narrowbeamcharacteristics

7.4.2.Narrowbeamlayout

7.4.3.Spatialprecisionandstability

7.4.4.Constructionandsurveys

7.4.5.Onlineandofflinealignment

7.5.Operationalaspects

7.5.1.Beammonitoringandsteering

7.5.2.Triggerandsynchronization

8.Infrastructureandservices

8.1.MovingtheTPC

8.2.Servicesupportwheel

8.3.Low-voltagedistribution

8.4.ChamberHVsystem

8.5.Gatepulser

8.6.Calibrationpulser

9.Detectorcontrolsystem（DCS）

9.1.Overview

9.1.1.Hardwarearchitecture

9.1.2.Softwarearchitecture

9.1.3.Systemimplementation

9.1.4.Interfacestodevices

9.1.5.Interlock

9.2.Electronicscontrol

9.2.1.Front-endmonitoring

9.2.2.Front-endconfigurationandcontrol

9.3.Interfacestoexperimentcontrolandoffline

10.Commissioningandcalibration

10.1.Calibrationrequirements

10.2.Commissioning

10.2.1.Commissioningphases

10.2.2.Datasets

10.3.Electronicscalibration

10.3.1.Pedestalandnoisedetermination

10.3.2.Tail-cancellationfilterparameterextraction

10.4.Gaincalibration

10.4.1.Kryptoncalibration

10.5.Drift-timecalibration

10.5.1.ShapingvariationsintheFEE

10.5.2.Driftvelocity

11.Performance

11.1.Space-pointresolution

11.2.Momentumresolution

11.3.Particleidentificationperformance

12.Conclusions

Acknowledgements

References

Past,presentandfutureofdataacquisitionsystemsinhighenergyphysicsexperiments  OriginalResearchArticle

MicroprocessorsandMicrosystems

DataAcquisition（DAQ）systemsforlargehigh-energyphysics（HEP）experimentsintheeightiesweredesignedtohandledataratesofmegabytespersecond.ThenextgenerationofHEPexperimentsatCERN（EuropeanLaboratoryforHighEnergyPhysics）,isbeingdesignedaroundthenewLargeHadronCollider（LHC）project,andwillhavetocopewithgigabyte-per-seconddataflows.

Asaconsequence,LHCexperimentswillrequirechallenginglynewequipmentfordetectorreadout,eventfiltering,eventbuildingandstorage.TheFastbusandVME-basedtreearchitecturesoftheeightiesrunoutofsteamwhenappliedtoLHC'srequirements.Newconceptsandarchitecturesfromtheninetieshavesubstitutedrack-mountingbackplanebusesforhighspeedpoint-to-pointlinks,abandonedcentralizedeventbuilding,andinsteaduseswitchednetworksandparallelarchitectures.

Followingthesetrends,andinthecontextofDAQandtriggersystemsforLHCexperiments,thispapersummarizestheearlierarchitecturesandpresentsthenewconceptsforDAQ.

ArticleOutline

1.Introduction

2.InstrumentationbusesforHEPinthe1960sand1970s

3.DAQandtriggersystemsinthe1980s

4.Newtrendsinthe1990s

5.TrendsinDAQsystemsforthe21stcentury

6.Conclusions

References

Vitae

Asoftwarepackagefortheconfigurationofhardwaredevicesfollowingagenericmodel  OriginalResearchArticle

ComputerPhysicsCommunications

ThispaperdescribesasoftwarepackagedevelopedinC++undertheLinuxenvironmentthatisintendedforautomatichardwareconfigurationinVMEorPCIbuses.Basedonagenericmodel,usersspecifytheconfigurationproceduresanddatainconfigurationfiles.Actualhardwareconfigurationisperformedbythesoftwarepackage,accessedthroughasimpleC++interface.ThemodeliswellsuitedforstorageofconfigurationdatainXMLfilesordatabases.ThepackageisnowbeingusedinthelocaldataacquisitionsystemoftheElectromagneticCalorimeteroftheCMSexperimentatCERN.

Programsummary

Titleofprogram:

GenericConfigurator

Catalogueidentifier:

ADUK

ProgramsummaryURL:

http:

//cpc.cs.qub.ac.uk/summaries/ADUK

Programobtainablefrom:

CPCProgramLibrary,Queen'sUniversityofBelfast,N.Ireland

Computerforwhichtheprogramisdesignedandothersonwhichithasbeentested:

IntelPentiumIVPC

Installations:

ECALDataAcquisitionoftheCMSexperimentatCERN

Operatingsystemsormonitorsunderwhichtheprogramhasbeentested:

Linux2.4.2

Programminglanguageused:

C++

Memoryrequiredtoexecutewithtypicaldata:

dependsonthecomplexityofthemoduleconfiguration.Testrunsrequireslessthen500KB

Numberofbitsinaword:

32

Numberofprocessorsused:

1

Distributionformat:

targzipfile

Numberofbytesindistributedprogram,includingtestdata,etc.:

234 542

Numberoflinesindistributedprogram,includingtestdataetc.:

17 365

Natureofphysicalproblem:

GeneralizationofhardwaredeviceconfigurationprocedureinVMEorPCIbuses.

Methodofsolution:

ThedevelopedpackageusesagenericconfigurationmodelthatallowsuserstoconfigureVMEandPCIdevices.Thehardwareconfigurationparametersa