kilometerscale neutrino observatories

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kilometer-scale neutrino observatories
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towards kilometer-scale neutrino detectors
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AMANDA Proof of Concept

• since 1992 we have deployed 24 strings with more
  than 750 photon detectors (basically 8-inch
  photomultipliers).
• RD detector for proof of concept 375 times
  SuperK instrumented volume with 1.5 the total
  photocathode area.
• IceCube 45 times AMANDA II instrumented volume
  with 7 times the total photocathode area.

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IceCube

• 80 Strings
• 4800 PMT
• Instrumented volume 1 km3
• (1 Gton)
• IceCube is designed to detect neutrinos of all
  flavors at energies from 107 eV (SN) to 1020 eV

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South Pole
AMANDA 1 mile deep
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South Pole
Dark sector
Skiway
AMANDA
Dome
IceCube
Planned Location 1 km east
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South Pole
Dark sector
Skiway
AMANDA
Dome
IceCube
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µ-event in IceCube300 atmospheric neutrinos per
day
AMANDA II
IceCube -gt Larger telescope -gt Superior
detector
1 km
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Muon Events
Eµ 10 TeV
Eµ 6 PeV
Measure energy by counting the number of fired
PMT. (This is a very simple but robust
method)
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Cherenkov light from muons and cascades
muon
cascade e or t

• Maximum likelihood method
• Use expected time profiles of photon flight times

Reconstruction
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AMANDA Event Signatures Cascades

• CC electron and tau neutrino interaction
• ?(e,?,) N ? (e, ?) X
• NC neutrino interaction
• ?x N ? ?x X

Cascades
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Cascade event
ne N --gt e- X

• the length of the e- cascade is small compared
  to the spacing of sensors.
• roughly spherical density distribution of light.
• 1 PeV 500 m diameter, additional 100 m per
  decade of energy
• linear energy resolution

Energy 375 TeV
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nt at E gt PeV Partially contained
Photoelectron density

• The incoming tau radiates little light.
• The energy of the second cascade can be measured
  with high precision.
• Signature Relatively low energy loss incoming
  track would be much brighter than the tau
  (compare to the PeV muon event shown before)

Timing, realistic spacing
Result high effective Volume, only second bang
needs to be seen in Ice3
10-20 OM early hits measuring the incoming t-track
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nt t
PeV t(300m)
t decays
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Neutrino ID (solid)Energy and angle (shaded)
Neutrino flavor

• Filled area particle id, direction, energy
• Shaded area energy only

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enhanced role of tau neutrinos

• cosmic beam ne nm nt
• because of oscillations

• nt not absorbed by the Earth
• (regeneration)

• pile-up near 1 PeV
• where ideal sensitivity

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Effective area of IceCube
Effective area vs. zenith angle (downgoing
muons rejected)
Effective area vs. muon energy (trigger, atm
?, pointing cuts)
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angular resolution as a function of zenith angle
Waveform information not used. Will
improve resolution for high energies !
0.8 0.6

• above 1 TeV, resolution 0.6 - 0.8 degrees for
  most zenith angles

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event rates before and after energy cut
Events per year at the ultimate AMANDA
sensitivity
Note300,000 atmospheric neutrinos per year (TeV
range)
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NEMO Actual proposal of general layout for Km3
detector

• n. 1 main Junction Box
• n. 8 secondary Junction Box
• n. 64 towers
• 200 m between each row and the others
• 200 m between each columns and the others
• 16 storeys for each tower
• 64 PMT for each tower
• 4096 PMT

secondary JB
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NEMO
The use of pipes to realize the storeys gives a
very low resistance to the water flow. The
largest estimated movement of the upper part of
the structure due to the currents are lower than
20m.

• The mechanical stresses on the rigid part of the
  structure are
• a bending due to the weight of the spheres when
  it is out of the sea water
• an axial load during the useful life due to the
  draught of the upper buoy.

The electro optical cables can be easily fixed on
the ropes.
During the deployment the main ropes can be kept
in position on the pipes by means of small
breakable ropes.
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• IceCube
• start 02
• first strings 04
• completed 09

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Drilling
Amanda (3-reel) and ICECUBE (1-reel) Drill
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Drilling
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Schedule and Cost
03-04 drill equipment to Pole 04-05 first
strings (proof that 16/season are feasible,
prepare 10 full strings)
05-06 16 strings 06-07 16 strings 07-08 16
strings 08-09 16 strings 09-10 remaining
strings
Overall cost with personnel, contingency,
overhead 250 M Detector 55 M
Logistics, including drilling 40 M
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evolution of read-out strategy
Test of ICE3 technology
01/02 - 03/04 Equipping all Amanda channels with
FADCs to get full
waveform information (IceCube
compatibility) ? better reconstruction,
particularly cascades and high energy tracks
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Assembled DOM
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IceCube has been designed as a discovery
instrument with improved

• telescope area ( gt 1km2 after all cuts)

• detection volume ( gt 1km3 after all cuts)

• energy measurement
• secondary muons ( lt 0.3 in ln E) and
• electromagnetic showers ( lt 20 in E)

• identification of neutrino flavor

• Sub-degree angular resolution
• (lt unavoidable neutrino-muon misalignment)

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AMANDA

• AMANDA collected gt 3,000 ns

• 4 more every day on-line

• neutrino sensitivity has reached n g

• gt 300,000 per year from IceCube

• race for solving the CR puzzle is on!

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conclusions

• nu astronomy reached 0.1 km2year

• will reach km-scale in lt 5 years

• northern hemisphere detectors soon

• EeV detectors over similar time scale

• if history repeats, I did not tell
• you about the science !!!

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The IceCube Collaboration

• Bartol Research Institute, University of
  Delaware
• BUGH Wuppertal, Germany
• Universite Libre de Bruxelles, Brussels, Belgium
• CTSPS, Clark-Atlanta University, Atlanta USA
• DESY-Zeuthen, Zeuthen, Germany
• Institute for Advanced Study, Princeton, USA
• Dept. of Technology, Kalmar University, Kalmar,
  Sweden
• Lawrence Berkeley National Laboratory, Berkeley,
  USA
• Department of Physics, Southern University and
  A\M College, Baton Rouge, LA, USA
• Dept. of Physics, UC Berkeley, USA
• Institute of Physics, University of Mainz, Mainz,
  Germany
• Dept. of Physics, University of Maryland, USA
• University of Mons-Hainaut, Mons, Belgium
• Dept. of Physics and Astronomy, University of
  Pennsylvania, Philadelphia, USA
• Dept. of Astronomy, Dept. of Physics, SSEC, PSL,
  University of Wisconsin, Madison, USA
• Physics Department, University of Wisconsin,
  River Falls, USA
• Division of High Energy Physics, Uppsala
  University, Uppsala, Sweden
• Fysikum, Stockholm University, Stockholm, Sweden
• University of Alabama, Tusceloosa, USA

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super-EeV detectors
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Event Rates

• volume eff. area threshold
• OWL 1013 ton 106 km2 3x1019 eV
• IceCube 109 ton 1km2 1015 eV

• Events per year
• TD Zburst p
• OWL ne 16 9 5
• Ice Cube nm 11 30 1.5

g2.7
Cline, Stecker astroph 0003459 Alvarez-Muniz
astroph 0007329 Warning models identical?
actual threshold 100GeV, gt 1 PeV no atmospheric
n background
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GZK Cosmic Rays Neutrinos
cosmogenic neutrinos are guaranteed fluxes
may be larger for some models, such as
topological defects
p gCMB ? p n
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Radio Emission from neutrino-induced
electromagnetic cascades

• Electromagnetic cascades electron-positron
  pairs and
• (mostly) gammas ? electrically neutral, no
  radio emission.
• Compton scattering of photons on atomic
  electrons creates
• negative charge excess of 20
• Negative charge radiates coherently at MHz GHz
  ?
• Power Energy 2
• Askarian effect demonstrated at SLAC consistent
  with
• calculations

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RICERadio Detection in South Pole Ice

• Installed 15 antennas
• few hundred m depth with
• AMANDA strings.
• Tests and data since 1996.
• Most events due to local
• radio noise, few candidates.
• Continuing to take data,
• and first limits prepared.
• Proposal to Piggyback with
• ICECUBE

Neutrino enters ice
Neutrino interacts
Antenna Cable
Two cones show 3 dB signal strength
Cube is .6 km on side
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TauWatchUsing Mountains to Convert ?t
3/02 Workshop in Taiwan, see http//hep1.phys.ntu.
edu.tw/vhetnw
also, HiRes, Auger.
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ANITA Radio from EeV ns in Polar Ice

• Antarctic Ice at flt1GHz, Tlt-20C
• largest homogenous, RF-transmissive solid mass
  in the world

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Antarctic Impulsive Transient Antenna (ANITA)
Solar Panels
M. Rosen, Univ. of Hawaii
ANITA Gondola Payload
Antenna array
Cover (partially cut away)

• ANITA Goal Pathfinding mission for GZK neutrinos
• NASA SRT start expected this October, launch in
  2006

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Ocean Acoustic Detection
New Stanford Effort using US Navy Array
US Navy acoustic tracking range in Tongue of the
Ocean, Atlantic
Hydrophones 1550-1600 m deep
pancake beam pattern
G.Gratta, atro-ph/0104033
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Summary on Technology
? Over 5 years, Amanda has evolved into a
30.000 m2 neutrino telescope ? Construction and
improvement hand in hand ? Developed and tested
IceCube technology ? Detailed measurement of ice
down to 2.4 km ? Clear record in performance,
reliability, time schedule and cost ? We know
that we can build a km3 telescope
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Summary Amanda Physics
? Diffuse flux Best limits. Entering interesting
range. ? EHE fluxes 0.3 km2 at EeV.
A-II testing EeV blazar models. ? Point sources
Best limits. Testing first models. ? GRB
sensitivity after 4 years close to predictions ?
Relativistic Magnetic Monopoles Best
limits (0.05 x Parker bound) ? WIMP search high
mass limits Underground limits ? Monitoring
Galaxy for SN bursts ? Cosmic Ray Composition at
knee
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... and IceCube Physics
? Diffuse flux sensitivity nearly factor 10
below WB limit ? EHE fluxes IceCube testing
some GZK models ? Point sources sensitivity
10-12 cm-2 s-1 for gt 1 TeV Many models predict
up to few tens of events/year ? GRB 10-100
events per year. Test WB model ? Rel.Magnetic
Monopoles lt 1/1000 Parker bound) ? WIMPs
complementary to future direct search expts. ?
SN monitoring up to LMC. Triangulation ? ?
Cosmic ray composition at knee