The evolution of high energy neutrino telescopes

Christian SpieringDESY

The evolution of high energy neutrino telescopes

…a long march which has notyet reachedits end.

under-ground

optical:- deep water- deep ice

- air showers- radio- acoustics

under-ground

optical:- deep water- deep ice

- air showers- radio- acoustics

This talk will essentially addressthe optical telescopes deep underwater and in ice. See the writtenversion for the high-energy frontierand the corrersponding techniques

Ann.Rev.Nucl.Sci 10 (1960) 63

Ann.Rev.Nucl.Sci 10 (1960) 1

Moisej Markov Bruno Pontecorvo

M.Markov,1960:

„We propose to install detectors deep in a lake or in the sea and to determine the direction of charged particles with the help of Cherenkov radiation“ Proc. 1960 ICHEP, Rochester, p. 578.

Central interest: cross sections, W-mass… one of the main motivations for Reines‘ South Africa detector, the Kolar Gold Field Detector (India) and the Baksan scintillation detector. Early sixties: does the neutrino cross section saturate beyond 1 GeV (i.e. one would never measure atm. neutrinos with energies higher than a few GeV). The question was relaxed in the mid seventies:

First measurement of atmospheric neutrinos

Beside several ideas like e.g.

H. Uberall and C. Cowan, 1965 CERN Conf. on Experimental Neutrino Physics, p. 231– Downward looking PM observing a

10 m thick water target, „possibly in ocean or a lake“

V. Bogatyrev, Yad.Fiz 13 (1971) 336– Three detectors each 107 tons of distilled

water a several km depth, widely spaced SN triangulation

in 1965 detection of nearly horizontal atmospheric neutrinos by F. Reines in a South African Gold mine.

DUMAND

1973 ICRC, Reines, Learned, Shapiro, Zatsepin, Miyake: a deep water detector to clarify puzzles in muon depth-intensity curves

Puzzles faded away, but there remained the awareness that such a detector could also work as neutrino detector

The name: DUMAND (Deep Underwater Muon And Neutrino Detector), proposed by Fred Reines

1975: First DUMAND Workshop in Washington State College DUMAND Steering Committee, chaied by F.Reines, J.

Learned, . A.Roberts

See also: A.Roberts: The birth of high-energy neutrino astronomy: a personal history of the DUMAND project,Rev. Mod. Phys. 64 (1992) 259.

Principle and capabilities

Angular resolution of 1° possible astrononomy

Energy resolution for muons is 50% at best, for 1 km track length

The DUMAND Workshops

An unbelievable source of basic ideas (including crazy ones which are sometimes the most exciting)

1976 Honolulu 1978 Scripps 1979 Khabarovsk/Baikal 1978 Honolulu Plus dedicated workshops on deployment, acoustic

detection, signal procressing and ocean engineering

Which physics?

UNDINE: UNderwater Detection of Interstellar Neutrino Emission

– i.e. Supernova too rarely to optimize an ocean detector for it ( IMB)

ATHENE: ATmospheric High-Energy Neutrino Experiment– Better with underground experiments

UNICORN: UNderwater Interstellar COsmic Ray Neutrinos– The high energy option

– preferred option, but: how large are the fluxes ? think as big as possible !

A. Roberts:

1978: 1.26 km³22,698 OMs

1980: 0.60 km³6,615 OMs

1982: 0.015 km³ 756 OMs

1988: 0.002 km³

216 OMs

DUMAND-II

Financial and technological reality !

DUMAND-II (The Octagon)

9 strings 216 OMs 100 diameter, 240 m height Depth of bottom: 4.8 km Lowest OM 100 m above

bottom

0

....

pnp

e

pp

e

or

Point sources, DUMAND-II (0.002 km³) expectations in the eighties !!!

Note: in 1989, the only proven TeV source was the Crab SNR!

With these assumptions, a km³ detector would have discovered 5-50 (worst scenario)

up to several ten thousand events (best scenario) per source

Diffuse sources, DUMAND-II (0.002 km³) expectations in the eighties

Technology boosts

Optical fibers with < 12 db attenuation over 40-km length and data rates of hundreds of MBaud (Nobel prize 2009!)

Appearance of 16“ Hamamatsu PMT

Appearance of 14“ „smart“ Philips PMT

JOMJapanese Optical Module

EOMEuropean Optical Module

1987: The SPS

1982-87: a series of 14 cruises, with two lost strings

1987: success !– depth-intensity curve– angular distributions– attenuation lenght (4722 m)

„Short Prototype String“

DUMAND after the SPS:

1989: HEPAP supports DUMAND-II 1990: DOE allocates funds for DUMAND-II Further financial cuts TRIAD (3 strings) 1993: shore cable laid December 1993: deployment of first string and

connection to junction box. Failure after several hours

1995: DUMAND project is terminated

Russia Very active during early DUMAND workshops

(Chudakov, Berezinsky, Bezrukov, Zhelesnykh, Petrukhin) Kicked out of DUMAND after Russian Afghanistan invasion

A. Roberts:

1980: Chudakov proposes exploration of Lake Baikal as possible site for a neutrino telescope

1981: start of site investigations at Lake Baikal (Domogatksy, Bezrukov)

Exploration of Atlantic, Black Sea, Indian Ocean, Pacific and Mediterranean sites (Zheleznyk, Petrukhin)

A. Roberts: „Communication among these groups is not very good“

The Lake BAIKAL experiment

G. Domogatsky

Bezrukov, Domogatsky, Berezinsky, Zatsepin

Largest fresh water reservoir in the world Deepest Lake (1.7 km) 1981: first site explorations & R&D Choosen site 3.6 km from shore, 1.3 km

depth

Ice as a natural deployment platform

… and its mis-interpretation:

A. Roberts:

Lake Baikal: the eighties

1984: first stationary string– Muon flux measurement

1986: second stationary string (Girlyanda 86)– Limits on GUT

magnetic monopoles All that with 15-cm

flat-window PMT FEU-49

Development of a Russian smart phototube (Quasar)

Towards NT-200 1988: Germany joins

1989/90: design of NT-200

1993 + 1994: NT-36 - 18 channels at 3 strings- first underwater array - first 2 neutrino candidates

1995: NT-72- 38 channels at 4 strings

1996: NT-96- 48 channels at 4 strings - clear neutrinos

1998: NT-200- 96 channels at 8 strings

4-string stage (1996)

J. Learned to C.Spiering:

„Congratulations for winningthe 3-string race!“(NT-36 vs TRIAD vs AMANDA)

NT-200

NT-200

3600 m

1366

m

2 PMTs in coincidenceto surpress background

NT200 results

Atmospheric neutrinos

WIMP search Diffuse neutrino fluxes

Skymap

GRB coincidences Magnetic monopoles

396 candidates

Amanda 4 years

Baikal 5 years

NT200+

NT200

3600 m

1366

m

140 m NT200+- upgrade 2005/06- 4 times better sensitivity than NT200 for PeV cascades- basic cell for km3 scale detector

construction 1993-1998

For searches of diffuse neutrino fluxes, the small NT200 could compete with the much larger Amanda by monitoring

a large volume below the detector. NT200+ fences this volume.

Gigaton Volume Detector, GVD

Sacrifice low energies (muon threshold ~ 10 TeV) Protoype strings being tested Modular clusters, stepwise installation > 2012 ~ 2000 optical modules (conventional PMs)

12 clusters of strings

NT1000: top view

R ~ 60 m

L~ 3

50

m

All other deep water/ice detector projects started around 1990 or later.

In the eighties /early nineties, shallow detectors have been proposed but never built.

On the other hand, deep underground detectors reached their full blossom:- solar neutrinos- supernova neutrinos- limits on proton decay- first hints to neutrino oscillations- sky maps

Shallow detector projects

Advantages: easy access, less challenging environment Disadvantages: huge background, not expandable

GRANDE– Shallow water, Lake, Arkansas, H. Sobel (Irvine)

LENA– Artificial water pool, Gran Sasso, M.Koshiba

SINGAO– Resistive Plate Chambers, Italy/UK

Swedish lakes– Early nineties, before Sweden joined Amanda

Underground Detectors

KGF

Baksan

FREJUS

Soudan

IMB

KamiokandeSuperkamiokande

MACRO

e.g. MACRO, 1356 upgoing muons

~ 1000 m²

Neutrino oscillations, proton decay

Deficit of solar neutrinos (see Kai Zuber‘s talk)

Deficit of atmospheric neutrinos as function of distance and energy

Stringent limits on proton life time

|m232| = (2.6±0.2) ·10-3 eV2

|m221| = (8.3±0.3) ·10-5 eV2

12 = 33.9º±1.6º23 = 45º±3º 13 < 9º

1990-2000: revisiting the expectations

Underground detectors, 1000 m², only for young Supernovae in our Galaxy (Berezinsky)

New estimates on neutrinos from Supernova remnants and other galactic sources based on observations with Whipple and HEGRA

For supernova remnants, microquasars, extragalactic sources: need detector of order 1 km³.

The Waxman-Bahcall bound

The Mannheim-Protheroe bound

GRB as sources of cosmic rays and neutrinos

bound

WB bound

MPR bound

Diffuse Fluxes 2002 This model was down-corrected by a factor of 20 in 2005.

The ice option

1988: Pomerantz workshop, NSF Science and Technology Center for the South Pole (A. Westphal, T.Miller, D. Lowder, B. Price)

E. Zeller (Kansas) suggests to F. Halzen radiodetection of neutrinos in Antarctic ice

1989: attempt of Westphal and Lowder to measure ice transparency in existing boreholes

Jan. 89, ICRC, Adelaide: Decide to propose Amanda (B. Price, D. Lowder, S. Barwick, B. Morse, F. Halzen, A. Watson)

1990: Morse et al. deploy PMTs in Greenland ice

F. Halzen

NatureSept 91

South Pole

1991/91 first small PMTs deployed Results consistent with 25 m absorption length

Heaters and pumpsto melt the holes

1 km

2 km

93/94

Catastrophal delay of light between

strings 20 m away!(µsec instead of 100 nsec)

40 m

Explanation remnant bubbles which are disapppearing withincreasing depth.

Amanda B4

1995: DESY and Stockholm build~ 100 modules, 86 deployed inthe season 95/96 at 1450-1950 m depth

The DESY crew

B4: first 2 neutrinos

DrillingHot water drillingHot water drilling

1 km

2 km

IceCube will work !

96/97 AMANDA - B10

120 m

AMANDA B10

NATURE 2001

Skyplot of thevery first 17Nu candidates in B10

B10 skyplot published in Nature 2001

1 km

2 km

120 m

3 long strings study deep and shallow ice for future IceCube

97/98

0.02 0.1 0.5

Scatteringcoefficient(1/m)vs. depth

1 km

2 km

AMANDA-II

99/00 200 m

Nearly horizontal

Ocean Water

AMANDA results

δ=90º

24h 0h

Max Significanceδ=54º, α=11.4h

3.38σ

No significant excess found

Diffuse fluxes Point sources Neutrinos from GRB WIMP searches Magnetic Monopoles Cosmic rays SN monitoring …. Skymap from 7years AMANDA: no significant excess

The one intriguing coincidence ….

Year2000 2001 2002 2003

May June July

Flux ofTeV photons

(arb. units)

0

1

2

3

WHIPPL

E

Arrival time of neutrinos from the direction of the AGN ES1959+650

05/06: 8

Remaining: 22 IceCube Strings 5 DeepCore Strings

complete in January 2011

04/05: 1

07/08: 18

06/07: 13

08/09: 19 strings

IceCube Observatory

Shadow of the MoonShadow of the Moon

Cosmic RaysCosmic Rays

Absolute pointing 1° Angular resolution 1°

0.5°

8 months IceCube 40 strings

Downward muons, max. 28° above horizon, median energy of primary parent ~ 30 TeV

Large-scale anisotropyof downgoing muons

IceCube (40 strings 2008)

anisotropies on theper-mille scale

(skymap in equatorialcoordinates)

90

-90

24h0

0 24h

90

-90

12 TeV

126 TeV

MILAGRO

Compare to Northern hemisphere

Tibet air shower array

Simulation(Lallement et al.Science 2005)

Compton-Getting effect ?

Heliosphere effect ? Nearby pulsar ? Interstellar magnetic

field ?

First observation on Southern hemi- sphere adds important piece of information.

First look above horizon (IceCube 2007, 22 strings)

PeV-EeV range

Southern hemisphere

Northern hemisphere

Point Sources: The Progress

factor

1000in 15 years !

Anotherfactor

1000 !

Diffuse Fluxes: The Progress

Baikal/

Mediterannean projects

NESTOR (since 1991) „Amanda-sized“ -- under construction (?)

ANTARES (since 1996)„Amanda sized“ -- data taking

NEMO: R&D for km3 project

Since 2003: km3 initiative KM3NeT

4100m

2400m

3400mANTARESNEMO NESTOR

NESTOR 1991:

first site studies 1992: first

muon count 1992-2001: many

ocean tests, build lab and infrastructure

2000: cable to site

2003: deploy first floor. Cable failure after a few weeks

Compare to 2000 declared plan: – deploy full tower

2003– deploy 6 more

towers 2005

ANTARES

Installation:Junction Box - Dec 2002Line 1 - March 2006Line 5-1 - Dec 2007Line 11-12 - May 2008

Antares results

NEMO R&D for KM3NeT- 4-floor tower in 2006- full tower end of 2009

KM3NeT

Recommendations KM3NeT

2001/02: High Energy Neutrino Astrophysics Panel– High physics interest– Need km³ scale– Need both hemispheres– No more than 1 Northern detector– Timely formation of Northern hemisphere deep water detector is encouraged

2008: ApPEC– The priority project for high energy neutrino astronomy is KM3NeT.– Encouraged by the significant technical progress of recent years, the support

for working towards KM3NeT is confirmed. – Resources for a Mediterranean detector should be pooled into a single

optimised design for a large research infrastructure, with installation starting in 2012.

– The sensitivity of KM3NeT must substantially exceed that of all existing neutrino detectors including IceCube.

KM3NeT

Mar

201

2

Design decision

Construction

2013

2017

2011

Data taking

2015

2 km Site Size Configuration Technology Deployment

…a long march which has notyet reachedits end.