A km 3 Neutrino Telescope: IceCube at the South Pole Howard Matis - LBNL for the IceCube...
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Transcript of A km 3 Neutrino Telescope: IceCube at the South Pole Howard Matis - LBNL for the IceCube...
A kmA km33 Neutrino Telescope: Neutrino Telescope: IceCube at the South PoleIceCube at the South Pole
Howard Matis - LBNLHoward Matis - LBNL
for the IceCube Collaborationfor the IceCube Collaboration
SPIE Hawaii - August 2002SPIE Hawaii - August 2002 H. Matis – Lawrence Berkeley National LaboratoryH. Matis – Lawrence Berkeley National Laboratory 22
Neutrino AstronomyNeutrino Astronomymeasuring measuring ss by its µ by its µ
Stable particles: Stable particles: p, p,
Astrophysical Astrophysical SourcesSources
• GRB, AGN, Super GRB, AGN, Super NovaeNovae
• GZK (p +CMB GZK (p +CMB ))• Topological defectsTopological defects
BackgroundsBackgrounds• Atmospheric Atmospheric ’’ss• Atmospheric Atmospheric ’’ss
IceCube
Earth
Accelerator
Target
SPIE Hawaii - August 2002SPIE Hawaii - August 2002 H. Matis – Lawrence Berkeley National LaboratoryH. Matis – Lawrence Berkeley National Laboratory 33
IceCubeIceCube
1400 m
2400 m
South Pole
IceTop
Skiway IceCube is designed IceCube is designed to detect neutrinos of to detect neutrinos of all flavors at energies all flavors at energies from 10from 1077 eV (SN) to eV (SN) to 10102020 eV eV
80 Strings80 Strings 4800 PMT 4800 PMT Instrumented volume: Instrumented volume:
1 km1 km33
Depth: 1400 m to Depth: 1400 m to 2400m2400m
Amanda
SPIE Hawaii - August 2002SPIE Hawaii - August 2002 H. Matis – Lawrence Berkeley National LaboratoryH. Matis – Lawrence Berkeley National Laboratory 44
South PoleSouth Pole
Dark sector
AMANDA
IceCube
Dome
Skiway
SPIE Hawaii - August 2002SPIE Hawaii - August 2002 H. Matis – Lawrence Berkeley National LaboratoryH. Matis – Lawrence Berkeley National Laboratory 55
Detecting Detecting ss
ss interact in earth interact in earth Produce µ (follows Produce µ (follows
path of path of )) Detect Cherenkov Detect Cherenkov
light in ice with light in ice with phototubes buried in phototubes buried in the icethe ice
Detect upward µDetect upward µss
Ice filters downward Ice filters downward cosmic µcosmic µss
QuickTime™ and aGIF decompressorare needed to see this picture.
SPIE Hawaii - August 2002SPIE Hawaii - August 2002 H. Matis – Lawrence Berkeley National LaboratoryH. Matis – Lawrence Berkeley National Laboratory 66
1 Km
•Measure energy at the detector by counting the number of fired PMTs and the total light.
Eµ=10 TeV Eµ= 6 PeV
Simulated Simulated + N + N -- + X + X
SPIE Hawaii - August 2002SPIE Hawaii - August 2002 H. Matis – Lawrence Berkeley National LaboratoryH. Matis – Lawrence Berkeley National Laboratory 77
Other ReactionsOther Reactionse + N e- + X
•Electron Cascade•1 PeV ≈ 500 m diameter
PeVPeV (300 m)(300 m)
decays
+ N - + X
SPIE Hawaii - August 2002SPIE Hawaii - August 2002 H. Matis – Lawrence Berkeley National LaboratoryH. Matis – Lawrence Berkeley National Laboratory 88
IceCubeIceCubeStringString
OM Spacing: 17 m
HV andBase
Gel
Main Cable
Glass pressuresphere rated to
10,000 psiOuter diameter: 13”
60 optical sensors/string
photomultiplier
1400 m
2400 m
DOM
String
SPIE Hawaii - August 2002SPIE Hawaii - August 2002 H. Matis – Lawrence Berkeley National LaboratoryH. Matis – Lawrence Berkeley National Laboratory 99
Digital Optical Module - (DOM)Digital Optical Module - (DOM)
Photomultiplier
Self-triggers on each pulseSelf-triggers on each pulse Captures waveformsCaptures waveforms Time-stamps each pulseTime-stamps each pulse Digitizes waveformsDigitizes waveforms Performs feature extractionPerforms feature extraction Buffers dataBuffers data Responds to Surface DAQResponds to Surface DAQ Set PMT HV, threshold, Set PMT HV, threshold, etcetc
33 cm
DOM Board
SPIE Hawaii - August 2002SPIE Hawaii - August 2002 H. Matis – Lawrence Berkeley National LaboratoryH. Matis – Lawrence Berkeley National Laboratory 1010
Requirements for One ElementRequirements for One ElementDigital Optical Module (DOM)Digital Optical Module (DOM)
Time resolution:Time resolution: < 5 ns rms< 5 ns rms Waveform captureWaveform capture
> 250 MHz> 250 MHz for first 500 nsfor first 500 ns ~ 40 MHz~ 40 MHz for 5000 nsfor 5000 ns
Dynamic RangeDynamic Range > 200 PE / 15 ns> 200 PE / 15 ns > 2000 PE / 5000 ns> 2000 PE / 5000 ns
Dead-timeDead-time < 1%< 1% OM noise rate OM noise rate < 500 Hz< 500 Hz ((4040K in glass sphere)K in glass sphere)
1 to 10,000 photons that are incident over several µs 1 to 10,000 photons that are incident over several µs
High dynamic range waveform recordingHigh dynamic range waveform recording
SPIE Hawaii - August 2002SPIE Hawaii - August 2002 H. Matis – Lawrence Berkeley National LaboratoryH. Matis – Lawrence Berkeley National Laboratory 1212
Time Time Synch-Synch-
ronizing ronizing ModulesModules
DOM
Surface
tdown =tup=1/2(Tround-trip- t)
t
SPIE Hawaii - August 2002SPIE Hawaii - August 2002 H. Matis – Lawrence Berkeley National LaboratoryH. Matis – Lawrence Berkeley National Laboratory 1414
DAQ DAQ Network Network
ArchitectureArchitecture
McParland et. al. -- A Preliminary Proposal for the IceCube DAQ System Architecture -- DRAFT7
DOMPair20 kB/sec
StringProcessor
N x 20 kB/sec
.
All Hits -0.6 MB/sec
80 Strings
String Subsystem:60 DOMs
N pairs
Event LAN100 BaseTTotal traffic: 1.6 MB/secStringCoincidenceMessagesGlobalTriggerEvent Triggers /Lookback Requests forall Strings - 0.8 MB/sec
EventBuilderBuilt events ~ 1 MB/sec(all event builders)
SAN(NetworkDisk Storage)
"DOMHUB"
Lookback RequestsString CoincidenceMessages - 170 kB/secFulfill Lookback Messages 0.6 MB/sec FulfillLookbackMessages
Online LAN100 BaseTTotal traffic: 1MB/sec
Proposed IceCube DAQ Network Architecture
String LAN100 BaseTTotal traffic: 0.6 MB/sec
OfflineDataHandlingTapeSatellite
String -Electronics in the ice Global
Timing
SPIE Hawaii - August 2002SPIE Hawaii - August 2002 H. Matis – Lawrence Berkeley National LaboratoryH. Matis – Lawrence Berkeley National Laboratory 1515
AMANDA String 18AMANDA String 18
Springboard for Springboard for transition to IceCubetransition to IceCube
41 DOMs deployed in 41 DOMs deployed in 99/00 season; 37 99/00 season; 37 operationaloperational
Test bed: download Test bed: download new code into icenew code into ice
Communicate and Communicate and program in North program in North AmericaAmerica
SPIE Hawaii - August 2002SPIE Hawaii - August 2002 H. Matis – Lawrence Berkeley National LaboratoryH. Matis – Lawrence Berkeley National Laboratory 1616
String 18 DOM BoardString 18 DOM Board
Oscillator
SPIE Hawaii - August 2002SPIE Hawaii - August 2002 H. Matis – Lawrence Berkeley National LaboratoryH. Matis – Lawrence Berkeley National Laboratory 1717
Digital ATWD WaveformsDigital ATWD WaveformsSingle PhotonADC Spectra
Complex Waveform@600 MHz
Time
ADC Charge
Hi Gain
Low Gain
No Gain
Clock
“Slow” ADC
•ATWD Channels 1 - 4: 1.7 ns/sample for 217 ns•ADC: 60 ns/sample for 7.7 s
“Bucket”
“Bucket”
“Bucket”
“Bucket”
“Bucket”
Digitalization @ ~ 600 Hz
SPIE Hawaii - August 2002SPIE Hawaii - August 2002 H. Matis – Lawrence Berkeley National LaboratoryH. Matis – Lawrence Berkeley National Laboratory 1818
Timing with “Phone Wire” to few nsTiming with “Phone Wire” to few ns
Transit time for 2.5 km twisted Transit time for 2.5 km twisted pair: ~12 pair: ~12 ss
Rise-time after propagation ~ 2 Rise-time after propagation ~ 2 s (~1/t)s (~1/t)
Use a bipolar “Time-Mark” Use a bipolar “Time-Mark” signal pulsesignal pulse
Digitize time-mark pulse @ 20 Digitize time-mark pulse @ 20 MHz, 10-bit MHz, 10-bit
Fit leading edge & baseline : Fit leading edge & baseline : 3.5 ns rms3.5 ns rms
SPIE Hawaii - August 2002SPIE Hawaii - August 2002 H. Matis – Lawrence Berkeley National LaboratoryH. Matis – Lawrence Berkeley National Laboratory 1919
Timing Timing with µwith µss
T (DOMN)
T (DOMN+1)
T = T (DOMN) - T (DOMN+1)
Two clear components:
• random coincidences (flat)
• correlated light (peak at ~ 0)
12 m
t - ns
SPIE Hawaii - August 2002SPIE Hawaii - August 2002 H. Matis – Lawrence Berkeley National LaboratoryH. Matis – Lawrence Berkeley National Laboratory 2020
Reconstructed Reconstructed Event Event
• Only first hit in each OM shown• Down flow of light• No “early photons”• Late hits consistent with:
• light scattering, or • a second ?
•Down going
SPIE Hawaii - August 2002SPIE Hawaii - August 2002 H. Matis – Lawrence Berkeley National LaboratoryH. Matis – Lawrence Berkeley National Laboratory 2121
String 18 PerformanceString 18 Performance
Timing: Timing: 3.5 ns rms3.5 ns rms (very stable)(very stable) SPE spectrum:SPE spectrum: as expectedas expected PMT Gain Drift:PMT Gain Drift: <<0.2 %/week<<0.2 %/week LED Beacons:LED Beacons: ~8 ns rms~8 ns rms (ice optics)(ice optics) Down going Down going :: observedobserved µ waveforms:µ waveforms: ~15%~15% have > 1 “hit” have > 1 “hit”
SPIE Hawaii - August 2002SPIE Hawaii - August 2002 H. Matis – Lawrence Berkeley National LaboratoryH. Matis – Lawrence Berkeley National Laboratory 2222
SummarySummary IceCube – New detector under development to explore IceCube – New detector under development to explore
astrophysical astrophysical ss
Decentralized timing with digital technologyDecentralized timing with digital technology Measure full waveformMeasure full waveform Provides more information for reconstructionProvides more information for reconstruction More detail for physics discoveryMore detail for physics discovery Feature extraction - less data to record and transmitFeature extraction - less data to record and transmit
Can synchronize separate and remote elements to Can synchronize separate and remote elements to several nsseveral ns
Fully functional prototypes tested with muons in AMANDAFully functional prototypes tested with muons in AMANDA Prototypes meet or exceed IceCube requirementsPrototypes meet or exceed IceCube requirements
SPIE Hawaii - August 2002SPIE Hawaii - August 2002 H. Matis – Lawrence Berkeley National LaboratoryH. Matis – Lawrence Berkeley National Laboratory 2323
Institutions: 11 US, 9 European, 1 Japanese and 1 Venezuelan;
1. Bartol Research Institute, University of Delaware (*)2. BUGH Wuppertal, Germany (*)3. Universite Libre de Bruxelles, Brussels, Belgium (*)4. CTSPS, Clark-Atlanta University, Atlanta, USA5. DESY-Zeuthen, Zeuthen, Germany (*)6. Institute for Advanced Study, Princeton, USA7. Lawrence Berkeley National Laboratory, Berkeley, USA (*)8. Department of Physics, Southern University and A\&M College, Baton Rouge, LA, USA9. Dept. of Physics, UC Berkeley, USA (*)10. Institute of Physics, University of Mainz, Mainz, Germany (*)11. University of Mons-Hainaut, Mons, Belgium (*)12. Dept. of Physics and Astronomy, University of Pennsylvania, Philadelphia, USA (*)13. Dept. of Astronomy, Dept. of Physics, SSEC, University of Wisconsin, Madison, USA (*)14. Physics Department, University of Wisconsin, River Falls, USA (*)15. Division of High Energy Physics, Uppsala University, Uppsala, Sweden (*)16. Dept. of Physics, Stockholm University, Stockholm, Sweden (*)17. Dept. of Physics, University of Alabama, USA18. Vrije Universiteit Brussel, Brussel, Belgium (*)19. Chiba University, Japan20. Dept. of Astrophysics, Imperial College, UK21. Dept. of Physics, University of Maryland, USA22. Universidad Simon Bolivar, Caracas, Venezuela (*) also in AMANDA
IceCube CollaborationIceCube Collaboration
SPIE Hawaii - August 2002SPIE Hawaii - August 2002 H. Matis – Lawrence Berkeley National LaboratoryH. Matis – Lawrence Berkeley National Laboratory 2424
The EndThe End