View
1
Download
0
Category
Preview:
Citation preview
FiTS:Fibre TransmissionSystem
Overview
• Maunakea SpectroscopicExplorer(MSE)– Background– Sciencegoals
• FiTS:TheFibre TransmissionSystem– Requirements– DesignandAnalysis– StatusandFutureWork
• TheUVic Fibre TestFacility– Goalsofthefacility– UVic /FTOTeam
• Conclusions
2FibreTransmissionsystem,12/8/2017
• Widefield,highlymultiplexedspectroscopicfacilitiesareurgentlyneeded,especiallytocomplementwidefieldimagingfacilities
• Itisrelativelystraightforwardtoupgrade3.6mCFHTtoawidefield11mtelescopeinexistingbuildingonMaunaKea(ina“dome”withalargeraperture)
• FormalconceptualdesignstudyhasjustbeencompletedbyinternationalpartnershipthatincludesCanada,France,Hawaii,China,India,Australia,Spain
• http://mse.cfht.hawaii.edu/
3FibreTransmissionsystem,12/8/2017
BackgroundonMSE
• TheUniverseiscomposedofDarkMatterandDarkEnergybothofwhicharechallengingforobservations
• DarkMatterperhapsbestexploredbystudyingverylargesamplesofstarsintheMilkyWay
• DarkEnergyperhapsbestexploredbystudyingverylargesamplesofgalaxiesatdifferentdistancesoverthewholesky
• =>Needprecisionspectroscopyoftenstohundredsofmillionsoffaintstarsandgalaxiesoverwholesky
4FibreTransmissionsystem,12/8/2017
BIGSciencequestions
WMAP9yr
SeeMSEDetailedSciencecase:http://mse.cfht.hawaii.edu/science/mse-science-docs/DSC/MSE_DSC_ExpDraft_27May2016.pdf
• Fainttargets=>largecollectingarea,veryefficientopticalsystem• Largearea=>largefield(effectivelylimitedbyphysicalsizesoflenses)• Typicaltargetdensities=>thousandsofspectra• Targetselection=>fibersareonlypracticalsolution• Precisionspectroscopyrequiresextremelywellcharacterized,stablespectra
5FibreTransmissionsystem,12/8/2017
SciencetoRequirements
Therefore,MSEtop-levelrequirementsare:• Telescope:11maperture,1.5sq.deg field• Wavelengthrange:0.37– 1.8um• >3200low/mediumresolutionspectra,>1000highresspectraperfield• SpectralresolutionfromR=2,500toR=40,000• Sensitivity:24magnitudeobjects(@SNR=2)• Spectro-photometricaccuracy<3%• Velocityprecisionof20km/s(@SNR=5)
• SciencerequirementsflowdownintokeyFiTS requirements– Throughput
• >90%@900nm(HRfibres)• >85%@900nm(LMRfibres)
– FocalRatioDegradation(FRD)<5%– Spectralandphotometricstability
• RequirementsstillTBD
• Howeverfibertransportusually producessignificantlightlosses,variabletransmissionandvariableimagequality– NeedtopaycarefulattentiontodetailsofdesignofFiTS,including
extensivetestingofalloptionsandcomponents
6FibreTransmissionsystem,12/8/2017
FiTS Requirements
7FibreTransmissionsystem,12/8/2017
FiTS Design
Fibre opticcablescarrylightfromMSEprime-focus…
To2High-ResolutionSpectrographs…
and6Low/Med-ResolutionSpectrographs(inthelowerCoudé room)
Distance:35mtoHR50mtoLMR
8FibreTransmissionsystem,12/8/2017
FiTS Design
MSETop-EndAssembly(primefocus)
Fibre positioningsystem(suppliedbyothers)• Individuallypositions4332fibres w/infield• De-rotatesfieldmotionduringobservation
9FibreTransmissionsystem,12/8/2017
CableDesignandAnalysis
• WorkingwithFibreTech Optica todevelopmodularfibre cables
• NeedhighthroughputfibrematerialsandexcellentARcoatings,overaverybroadwavelengthrange
• PreparingforDelta-CoDR inlatewinter/earlyspring• Currentlyworkingtofullydefinerequirements• Projectstillneeds:
– Betterdefinitionofintegrationandtestsequencewiththepositioningsystemandtelescope
– Aplanforaddressingstabilityrequirements,throughmodellingortesting– Researchintocandidatefibre materials– ResearchintobroadbandARcoatingsforfibres
• Projectwillbeamulti-milliondollareffort– Testingofsomanyfibres istimeconsumingandexpensive
10FibreTransmissionsystem,12/8/2017
StatusandFutureWork
• CurrentlybeingbuiltinDr.ColinBradley’slabwithintheDepartmentofMechanicalEngineering
• BeganconstructioninNovemberfollowingavisittoFiberTech Optica(FTO)bytwoteammembers(seeposter!)
• Plannedtestsinclude:• Ringtest
• explorefibre focalratiodegradation(FRD),aimingtoverifytheFRD< 5%requirement
• Formedbeamtest• studytheeffectsoffibre cladding,joiningproceduresanddynamics
onFRD(simulatingon-skyconditions)• Multi-fibre behaviour,cross-talkandthroughput• Testautomation
11
UVicFiTSFacility
FibreTransmissionsystem,12/8/2017
SchematicoftheFormedBeamTest
12
UVicFiTSFacilityII
FibreTransmissionsystem,12/8/2017
SchematicoftheRingTest
• StephanieMonty(BScstudent,Astronomy)– Managingproject,responsibleforrequirementsdefinition
• FarbodJahandar(MScstudent,Astronomy)andCollinKielty(PhDstudent,Astronomy)– Softwaredevelopment,imageprocessingandmotioncontrol
• Jooyoung Lee(MASc student,Mech Engineering)– Opto-mechanicaldesign,hardwaredevelopment
• SupervisionfromDr.KimVenn(PhysicsandAstronomy)andDr.ColinBradley(Mech Engineering)
13FibreTransmissionsystem,12/8/2017
UVICTeam
• MSEisanexcitingproject,addressingtheneedforhighly-multiplexed,wide-fieldspectroscopy
• FiTS Fibre TransmissionSystemisanintegralpartofthefacilitydesign– Requirementsandscaleofprojectarechallenging
• Challengesexistinthedesign,constructionandtesting• KeystosuccessareastrongpartnershipbetweenNRC-H,FTO
andUVic,leveragingthecapabilitiesofeachorganization
14FibreTransmissionsystem,12/8/2017
Conclusions
Recommended