The Baikal Neutrino Telescope - - Status and Plans Status and - - PowerPoint PPT Presentation

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The Baikal Neutrino Telescope - - Status and Plans Status and - - PowerPoint PPT Presentation

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The Baikal Neutrino Telescope - - Status and Plans Status and Plans The Baikal Neutrino Telescope Outline: - Detection Methods - The Detectors: NT200 and NT200+ - Physics Results from NT200 Diffuse cosmic neutrino search - The Km3

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The Baikal Neutrino Telescope The Baikal Neutrino Telescope -

  • Status and Plans

Status and Plans

30 30th

th ICRC,

ICRC, Merida Merida, Mexico, July 2007 , Mexico, July 2007

Ralf Wischnewski

DESY, Zeuthen

  • for the Baikal Collaboration -

Outline:

  • Detection Methods
  • The Detectors: NT200 and NT200+
  • Physics Results from NT200

Diffuse cosmic neutrino search

  • The Km3 Baikal Detector Project

( “Gigaton Volume Detector” ) Poster:

  • A prototype acoustic neutrino detector / 0639
  • NT200 Physics Results / 1088
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R.Wischnewski ICRC, Merida, 2007

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The Baikal Collaboration

  • Institute of Nuclear Research, Moscow
  • Moscow State University
  • DESY Zeuthen
  • Irkutsk State University
  • Nishni Novgorod State Techn. Univ.
  • State Marine Techn. Univ. St.Petersburg
  • Kurchatov Institute, Moscow
  • JINR, Dubna

~45 authors

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R.Wischnewski ICRC, Merida, 2007

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Project Milestones

>1983: Site / Water studies; R&D: large area PMT, underwater technology, Physics small setups (exotics search) 1991: Project NT200 submitted 1993: NT36 – the first underwater array operates 1998: NT200 commissioned 2005 - 2006: Upgrade to NT200+ completed; operating >2006: R&D activity for a Km3 detector in Lake Baikal („Gigaton Volume Detector“) ~2010: expected start of Km3 deployment

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R.Wischnewski ICRC, Merida, 2007

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Baikal

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R.Wischnewski ICRC, Merida, 2007

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4km OffShore Depth: 1366m Shore Station

Lake Baikal

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R.Wischnewski ICRC, Merida, 2007

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NT200+

= NT200 + 3 long outer strings

  • Height = 210m

Height = 210m

  • ∅ = 200m

= 200m

  • Geom.Volume

Geom.Volume ~ 5 ~ 5 Mton Mton

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SLIDE 7

The NT-200 Telescope

  • 8 strings
  • 192 optical modules

= 96 pairs (coincidence)

  • measure Time, Charge
  • σT ~ 1 ns
  • dyn. range ~ 1000 p.e.

Effective area: 1 TeV ~ 2000 m²

  • Eff. Shower volume: 10 TeV ~ 0.2Mt

1 PeV ~ 1Mton !

Quasar PMT: d=37cm (14.6”)

Height = 70m, ∅ = 42m Vinst = 105 m3

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R.Wischnewski ICRC, Merida, 2007

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ExtString 1 ExtString 3 ExtString 2 NT200 Central+Outer Str.

New ShoreCable

100 m

Advantages (1): Ice – Perfect Deployment Platform

  • Ice is available for 6-8 winter-weeks/year :

– Upgrades & maintenance – Test & installation of new equipment – Operation of surface detectors (EAS, acoustics,… ) – Electrical winches used for deployment operations (all connections done dry)

Foto from March, 2005, 4km off-s NT200+ deployment from 1m thick

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R.Wischnewski ICRC, Merida, 2007

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  • Scatt. Length ~ 30-50 m

〈cos Θ〉 ~ 0.85-0.9

In-situ measurements

  • ver many years

Note: IceCube‘s „effective“ (diffusion) scattering is ~30m for Baikal: ~300 - 500m !

Baikal Baikal

λ, nm λ, nm A b s

  • r

p t i

  • n

c r

  • s

s s e c t i

  • n

, m-1 S c a t t e r i n g c r

  • s

s s e c t i

  • n

, m-1

Advantages (2): Water – Good Optical Properties

Baikal: Baikal: Fresh water Fresh water

  • No K40 BG

No K40 BG

Short periods of Short periods of ~15m possible. ~15m possible.

  • Abs. Length: 22 ± 2 m

(geom.scat.L.)

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R.Wischnewski ICRC, Merida, 2007

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Calibration Laser ~ 1012 – 5 1013 γ/pulse (1 ns)

→ E_Shower ~ 10 – 500 PeV

  • Measure:

Photon arrival times on Chan13 @187m distance

  • Time Jitter = Scattering + Electronics

In-situ: Verification of Scattering @ large distances

FWHM ~12ns @2pe,190m !

t t13

13

t t106

106

1 10 100 2 4 6 8 10

σ, ns

Np.e.

Light scattering Light scattering

  • scattering length 30 m

scattering length 30 m

  • distance to Laser ~200 m

distance to Laser ~200 m

σT vs. number of p.e.

Laser

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NT200 - Selected Results

  • Low energy phenomena
  • Atmospheric neutrinos
  • WIMP Neutrinos
  • Search for exotic particles
  • Relativistic Magnetic monopoles
  • High energy phenomena
  • D

Diffuse neutrino flux iffuse neutrino flux

  • Neutrinos from GRB
  • Prompt muons and neutrinos
  • Exotic HE muons

Data sample:

1998-2002 (Apr/98-Feb/03) 1038 days

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R.Wischnewski ICRC, Merida, 2007

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Atmospheric Muon-Neutrinos

  • Data: 372 upward ν events (1998-2002).

( Nμ(>15GeV)/Nμ(>1GeV)~1/7 )

  • MC: 385 ev. expected (15%BG).

A high statistics neutrino sample for Point-Source Search, incl. GalCenter. No evidence for non-atmosph. ν‘s.

Skyplot of NT200 neutrino events / 5 years

(galactic coordinates) E_thr E_thr ~ 15GeV ~ 15GeV

Galactic center visible 18 hours per day

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R.Wischnewski ICRC, Merida, 2007

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Monopole selection criteria:

  • large hit channel multiplicity: Nhit > 35 ch
  • clearly upward going track

Background : atmospheric muons (downward) Nγ (λ) = n2 (g/e)2 Nγμ(λ) = 8300 Nγμ(λ) (!!) g = 137/2, n = 1.33

Bright light source, like muons ~Eμ=107 GeV

90% C.L. upper limit on the flux of fast monopoles (1003 livedays).

10

  • 17

10

  • 16

10

  • 15

0.6 0.8 1 Nhit vs distance NT200 (1998-2002)

Baikal, 2006 Baikal, 2006

Search for Fast Monopoles (β > 0.8)

Amanda-II/ICRC2007

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R.Wischnewski ICRC, Merida, 2007

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Search for High Energy Diffuse Cascades

Search within non-instrumented volume below NT200 detector for cascades = Upward moving light fronts.

μ („BG“)

l a r g e e f f e c t i v e v

  • l

u m e

ν

NT200

Vgeo (NT200) 10 Mton

Effective Volume vs. Energy

NT200+ : Instrument the volume below detector better BG suppression and improved physics. Vdet > 1 Mton at 1 PeV

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R.Wischnewski ICRC, Merida, 2007

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Diffuse Flux Limits

Astropart.Phys. 25 (2006) 140

Amanda-II, this conf.

10

  • 8

10

  • 7

10

  • 6

10

  • 5

3 4 5 6 7 8 9 10 11 νe:νµ:ντ=1:1:1 TD NMB WB MPR B B(E-2)

lg(E/GeV) E2 Φ(E), GeV cm

  • 2 s-1 sr-1

MPR

atm.

ν νpr BAIKAL

BAIKAL( ν

  • e, res)

Υ

AMANDA Υ AMANDA( ν

  • e, res)

MACRO NT200+ (3 years)

µ

ν

AMANDA II

*3

Exp.νµ limits are

multiplied x3

1:1:1 flavor flux ratio @earth assumed (source1:2:0)

limits given for all-flavors NT200+ sensitivity (~ Amanda-II)

  • Exp. Limits, model predictions,

and atmospheric ν-BG. For a γ=2 spectrum Фν ~ E-2 the Baikal NT200 limit is (20 TeV < E < 50 PeV): E2 Фν < 8.1 ·10-7 GeV cm-2 s-1 sr-1

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  • 2.12

SeSi 2.0 4.0 MPR 1.99 1.14 P Pγ

  • 2.86

M pp+pγ 0.28 0.37 SP l 0.054 0.062 SP u 1.6 2.5 SS05 Quasar AMANDA BAIKAL Model

Limits on Neutrino Source Models

Model survival factor n90% /Nmodel

Neutrinos from Quasar Cores

SS – Stecker, Salamon (91,05) SP – Szabo, Protheroe (92)

Neutrinos from Blazars

M pp+pγ - Mannheim (95) P pγ

  • Protheroe (96)

MPR - Mannheim, Protheroe, Rachen (01) SeSi - Semikoz, Sigl, (03)

10

  • 7

10

  • 6

10

  • 5

3 4 5 6 7 8 9 10

νe:νµ:ντ=1:1:1 SeSi SS91 SS05 SS91=10 SS05 SeSi BAIKAL SS

lg(E/GeV) E2Φ,[GeV s-1 sr-1cm-2]

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The New Project: A Km3 – size Detector in Lake Baikal (“Gigaton Volume Detector”)

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R.Wischnewski ICRC, Merida, 2007

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A Km3 - Scale Baikal Neutrino Detector

624m 280m

70m 70m 120m

208m

A sparsely instrumented array:

  • 1300-1700 OMs
  • 90-100 strings, 350m length
  • 12-16 OM/string
  • string radial distance ~120m *

Casacde effective volume for

≥ 100 TeV: ~ 0.5-1. km³

δlg(E) ~ 0.1, δθmed < 4o

Muon detection from 10-30TeV

*Toy model (MC optimization in progress) Basic cell: a minimized NT200+ Basic cell: a minimized NT200+

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0.2 0.4 0.6 0.8 1 1 1.5 2 2.5 3 3.5 4 4.5

lg(Esh/TeV) I(E)/I(1 PeV)

cascades

0.2 0.4 0.6 0.8 1 1 1.5 2 2.5 3 3.5 4 4.5

lg(Eµ/TeV) I(E)/I(100 PeV)

muons

contained events

instrumented volume V=3.5 108 m3 <S>= 0.8 106 m2

Km3 Design Studies (in progress)

16 Channel / String (Channel = 1 OM) 8 Channel / String (Channel = 2 OM)

Cascades Muons

lg(E_mu/TeV) lg(E_sh/TeV)

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PMT Selection for Km3

Basic criteria of PM selection is effective sensitivity to Basic criteria of PM selection is effective sensitivity to Cherenkov Cherenkov light light which depends on which depends on Photocathode area Photocathode area × × Quantum efficiency Quantum efficiency × × Collection efficiency Collection efficiency and Optical Module design (FOV). and Optical Module design (FOV).

Quasar-370 D ≈ 14.6” Quantum efficiency ≈ 0.15 Hamamatsu R8055 D ≈ 13” Quantum efficiency ≈ 0.20

? ? ≈ ≈ ? ? ≈ ≈

Photonis XP1807 D ≈ 12” Quantum efficiency ≈ 0.24

Baikal Baikal NT200+ NT200+ IceCube IceCube Antares Antares NEMO? NEMO?

PMT development now is an active field with KM3NET/ BAIKAL PMT development now is an active field with KM3NET/ BAIKAL-

  • km3/

km3/… … : : QE >30% , new Smart QE >30% , new Smart-

  • PMT designs (QUASAR

PMT designs (QUASAR-

  • like by

like by Photonis Photonis/ /… …?), ?), … …

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R.Wischnewski ICRC, Merida, 2007

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6 new PMTs installed in April 2007 inside NT200+:

  • 4 PM R8055 (Hamamatsu)
  • 2 XP1807 (Photonis)

FADC readout for 2xR8055. Quasar Quasar-

  • 370

370 Quasar Quasar-

  • 370

370 Quasar Quasar-

  • 370

370 Quasar Quasar-

  • 370

370 R8055 R8055 XP1807 XP1807

PMT Selection: Underwater Tests (2007)

Laser Laser

160…180 m

1 2 3 4 5 6 0,0 0,2 0,4 0,6 0,8 1,0 1,2 1,4

XP1807 #1026 XP1807 #1006 R8055 #186 R8055 #314 R8055 #228 Quasar-370 Relative PM sensitivities PMT number

Relative effective sensitivities of large area PMs R8055/13” , XP1807/12” and Quasar-370/14.6”. Laboratory (squares) and in-situ tests (dots).

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FADC

OM3 OM1 OM2 OM6 OM4 OM5 OM3 OM1 OM2 OM6 OM4 OM5

Km3 Baikal Project NT200+ current status Prototype string April 2008: Installation of a “new technology” prototype string as part of NT200+

Investigation and in-situ tests of all basic elements of the future detector:

  • Optical modules
  • DAQ system
  • new cable communications.

Study of DAQ/Triggering concept for the km3-detector; e.g. “quasi-local coincidences” Comparison of new FADC readout with classical TDC/ADC approach (200MHz).

Prototype String for Km3 Baikal Neutrino Telescope

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Baikal – Km3: Schedule

  • 06-07 R&D, Testing NT200+
  • 08 Technical Design
  • 08-14 Fabrication (OMs, cables,

connectors, electronics)

  • 10-12 Deployment (0.1 – 0.3) km3
  • 13-14 Deployment (0.3 – 0.6) km3
  • 15-16 Deployment (0.6 – 0.9) km3
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  • The Baikal Neutrino Telescope operates successfully since 1998.
  • NT200 : focusing on diffuse HE-neutrino search.
  • HE-diffuse search: A “Mton-detector” with only 100kton geometric volume.
  • Magnetic Monopoles, WIMPs, HE-atm.μ
  • NT200+ : is designed for diffuse cosmic ν-search.
  • 4x sensitivity gain; improved vertex, energy + direction for shower.
  • 5 Mton instrumented volume, V_eff > 10 Mton at 10 PeV.
  • Baikal-Km3 activities started in 2006.
  • Optimal PMT choice & redesign of F/E & trigger electronics.
  • 2008: Deploy prototype km3-string.

Design based on NT200+ experience and in-situ tests.

Summary

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Thank you. Thank you.

Final deployment step for NT200+. April, 2005. Final deployment step for NT200+. April, 2005.