TAUP 2003 The Ice Cube Neutrino Telescope Project

TAUP 2003 The Ice. Cube Neutrino Telescope Project overview and Status EHE Physics Example: Detection of GZK neutrinos Shigeru Yoshida, Chiba University

l l l The Ice. Cube collaboration Chiba University, Chiba, Japan l Clark Atlanta University, Atlanta, GA DESY-Zeuthen, Germany Imperial College, UK Institute for Advanced Study, Princeton, NJ Lawrence Berkeley National Laboratory, Berkeley, CA Pennsylvania State University, Philadelphia, PA South Pole Station, Antarctica Southern University and A & M College, Baton Rouge, LA Stockholm Universitet, Stockholm, Sweden Universität, Mainz, Germany Universität Wuppertal, Germany l l l Université Libre de Bruxeelles, Bruxelles, Belgium Université de Mons-Hainaut, Mons, Belgium University of Alabama, Tuscaloosa, AL University of California-Barkeley, Berkeley, CA University of Delaware, Newark, DE University of Kansas, Lawrence, KS University of Maryland, College Park, MD University of Wisconsin-Madison, WI University of Wisconsi-River. Falls, River Falls, WI Universidad Simon Bolivar, Caracas, Venezuela Uppsala Universitet, Uppsala, Sweden Vriie Universiteit Brussel, Brussels, Belgium

South Pole Dark sector Skiway AMANDA Dome Ice. Cube

Ice. Cube Ice. Top AMANDA South Pole Skiway 80 Strings 4800 PMT Instrumented volume: 1 km 3 (1 Gt) Ice. Cube is designed 1400 m to detect neutrinos of all flavors at energies from 107 e. V (SN) to 1020 e. V 2400 m

How our events look like The typical light cylinder generated by a muon of 100 Ge. V is 20 m, 1 Pe. V 400 m, 1 Ee. V it is about 600 to 700 m. Eµ=10 Te. V ≈ 90 hits Eµ=6 Pe. V ≈ 1000 hits

DAQ design: Digital Optical Module - PMT pulses are digitized in the Ice Design parameters: Time resolution: ≤ 5 nsec (system level) Dynamic range: 200 photoelectrons/15 nsec (Integrated dynamic range: > 2000 photoelectrons) (1. p. e. /10 ns ~ 160 A 10^7 G ~8 m. V 50 W) 4 V saturation 500 p. e. Digitization depth: 4 µsec. Noise rate in situ: ≤ 500 Hz Tube trig. rate by muons 20 Hz DOM 33 cm

Capture Waveform information (MC) ATWD 300 MHz String 1 14 bits. 3 different gains (x 15 x 3 x 0. 5) Capture inter. 426 nsec 10 bits FADC for long duration pulse. Events / 10 nsec 0 - 4 µsec String 2 String 3 String 4 t E=10 Pe. V String 5

Photomultiplier: Hamamatsu R 7081 -02 (10”, 10 -stage, 1 E+08 gain) • Selection criteria (@ -40 °C) • • Noise < 300 Hz (SN, bandwidth) Gain > 5 E 7 at 2 k. V (nom. 1 E 7 + margin) P/V > 2. 0 (Charge res. ; insitu gain calibration) Notes: • • Only Hamamatsu PMT meets excellent low noise rates! Tested three flavors of R 7081.

Digital Optical Module (DOM) Main Board Test Card

SPE Discriminator Scan – PMT Pulses Input (71 DB)

The big reel for the hotwater drill

Energy Spectrum Diffuse Search Ed. N/d. E=10 -7 Ge. V/cm 2 sec sr Emax 108 Ge. V Blue: after downgoing muon rejection Red: after cut on Nhit to improve sensitivity

Aeff / km 2 Effective area of Ice. Cube cos Effective area vs. zenith angle after rejection of background from downgoing atmospheric muons Note: Should be further improved by utilizing waveform information

Coincident events Energy range: l ~3 x 1014 -- 1018 e. V Two functions l l l veto and calibration cosmic-ray physics few to thousands of muons per event Measure: l l Shower size at surface High energy muon component in ice Large solid angle l l l One Ice. Top station per hole ~ 0. 5 sr for C-R physics with “contained” trajectories Larger aperture as veto Ice. Top

In three years operation… TAUP 2003 E 2 d. N /d. E ~10 -8 Ge. V/cm 2 s sr (diffuse) E 2 d. N /d. E ~7 x 10 -9 Ge. V/cm 2 s (Point source) 200 bursts in coincidence n(GRBs – WB o i t flux) c e t e d s 5 r o F

Construction: 11/2004 -01/2009 Grid North 100 m Co-operation of AMANDA-Ice. Cube From the 1 st year AMANDA South Pole SPASE-2 Dome Skiway Next season: Buildup of the Drill and Ice. Top prototypes

TAUP 2003 Project status Startup phase has been approved by the U. S. NSB and funds have been allocated. 100 DOMs are produced and being tested this year. Assembling of the drill/Ice. Top prototypes is carried out at the pole this season. Full Construction start in 04/05; takes 6 years to complete. Then 16 strings per season, increased rate may be possible.

TAUP 2003 GZK EHE detection What is the GZK mechanism? EHE / /t Propagation in the Earth Expected intensities at the Ice. Cube depth Atmospheric – background Event rate

GZK Neutrino Production p E = 10 20 e. V γ π＋ ν ＋ μ e ＋ γ ν p n E ~ 0. 8 x 10 20 e. V 0. 6 x 10 -27 cm 2 2. 725 K 411 photons / cm 3 　　 Conventional Mechanism of EHE neutrinos!!

Note: The oscillations convert e, to e, , t Yoshida and Teshima 1993 Yoshida, Dai, Jui, Sommers 1997 TAUP 2003

Products e e t e/ Weak t p Weak e/ p Weak t t Weak Incoming Weak Cascades Decay Weak Decay Pair/decay Pair Bremss Decay Weak Pair Bremss Decay Pair Photo. Nucl. Decay Photo. Nucl. Cascades

Muon(Neutrinos) from t Tau(Neutrinos) from Nadir Angle Suppression By t decay TAUP 2003 t

ν Downward lepton １．４ｋ ｍ e +e － γ γ Ice １ｋｍ Rock ν １ｋｍ e +e － γ π± lepton Upward ν

Upward-going Downward going!! Atmospheric muon! – a major backgrond But so steep spectrum TAUP 2003

Down-going events dominate… Atmospheric is strongly attenuated… 11000 m Up Down 2800 m 1400 m TAUP 2003

Flux as a function of energy deposit in km 3 d. E/d. X~b. E DE~DXb. E

Intensity of EHE and t [cm-2 sec-1] GZK m=4 I (E>10 Pe. V) It(E>10 Pe. V) Zmax=4 RATE [/yr/km 2] Down 5. 90 10 -19 5. 97 10 -19 0. 37 Up 3. 91 10 -20 6. 63 10 -20 0. 03 I (E>10 Pe. V) It(E>10 Pe. V) Energy Deposit Down 4. 75 10 -19 2. 94 10 -19 0. 24 m=7 Zmax=5 Down 7. 21 10 -17 4. 83 10 -17 37. 9 Atm m 1. 74 10 -19 0. 05 TAUP 2003

TAUP 2003 Conclusion Ice. Cube has great capability for Te. V-Pe. V -induced muons taking advantage of long range in the clear ice. For EHE like the GZK…. t/ appeared in 10 Pe. V- Ee. V are our prime target on GZK detection. 1/100 -1/500 of primary Downward t and make main contributions in Pe. V -Ee. V intensity! Energy Estimation would be a key for the bg reduction Because atmospheric spectrum ~ E-3. 7 GZK is DETECTABLE by Ice. Cube 0. 2 -40 events/year (BG 0. 05 events/year)

Backup slides

Theoretical bounds and future DUMAND test string FREJUS MACRO opaque for neutrons AMANDA-00 AMANDA-II ric sphe atmo NT-200 AMANDA-97 MPR neutrons can escape NT-200+ W&B Ice. Cube Mannheim, Protheroe and Rachen (2000) – Waxman, Bahcall (1999) derived from known limits on extragalactic protons + -ray flux

UHE (Ee. V or even higher) Neutrino Events Arriving Extremely Horizontally • Needs Detailed Estimation • Limited Solid Angle Window (sr. NA)-1 ~ 600 (s/10 -32 cm 2) -1(r/2. 6 g cm-3) -1 [km] Involving the interactions generating electromagnetic/hadron cascades N X e+e- TAUP 2003

t/ propagation in Earth TAUP 2003

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