Baikal Neutrino Telescope –an underwater laboratory for
astroparticle physics and environmental studies.
N. Budnev, Irkutsk State University.For the Baikal Collaboration
BAIKAL - CollaborationBAIKAL - Collaboration
Institute for Nuclear Research, Moscow, Russia.
Irkutsk State University, Russia.
Skobeltsyn Institute of Nuclear Physics MSU, Moscow, Russia.
DESY-Zeuthen, Zeuthen, Germany.
Joint Institute for Nuclear Research, Dubna, Russia.
Nizhny Novgorod State Technical University, Russia.
St.Petersburg State Marine University, Russia.
Kurchatov Institute, Moscow, Russia.
Messengers from the Universe
• Photons currently provide all information on the Universe. But they are rather strongly reprocessed and absorbed in their sources and during propagation. For Eg > 500 TeV photons do not survive journey from Galactic Centre.
• Protons+Nuclear directions scrambled by galactic and intergalactic magnetic fields as well for Epr >2021 eV they loss energy due to interaction with relict radiation (GZK-effect).
• NeutrinosNeutrinos have discovery potential because they have discovery potential because they open a new window on the Universeopen a new window on the Universe
W49B
SN 0540-69.3
Crab
E0102-72.3
Cas A
P+Nuclears
1960 - M. Markov: High Energy neutrino detection in natural transparent media (ocean water, ice):
O(km) long muon tracks
5-15 m
Charged Current (CC)
Electromagnetic & hadronic cascades
~ 5 m
CC e + Neutral Current
log(
E2
Flu
x)
log(E/GeV)TeV PeV EeV
3 6 9
pp core AGN p blazar jet
Top-Bottom GZK
GRB (W&B)
WIMPsWIMPsOscillationsOscillations
UndergroundUnderground
UnderwaterUnderwaterRadio,AcousticRadio,Acoustic
Air showersAir showers
Microquasars etc.
A
NT200+/Baikal-GVD1993-1998 (~2015)
N N
KM3NeT(~2014)
Amanda/IceCube/IceCube1996-2000 (~2011)(~2011)
ANTARES
NEMO
NESTOR
First underwater neutrino telescope NT200
The first underwater neutrino telescope NT200have been operated in Lake Baikal since 1998.
Length – 720 km, width – 30-50 km, depth -1300-1640 m20% of kind fresh water
Why Lake Baikal?
Site conditions
• Sufficient depth (1370 m) is located at distance 3 km from the shore.
• Absorption length typically is (20 – 25) m, scattering length typically is (50 – 70!) m.
• No bioluminescence flashes, background, as a rule, in 10 -100 times less then in a sea water.
• Small water currents, especially at large depths (a few millimeters per second).
• Fresh water, cheaper materials can be used.• Convenient transport communication.
Ice as a natural deployment Ice as a natural deployment platformplatform
Ice stable for 6-8 weeks/year: Ice stable for 6-8 weeks/year:
– Maintenance & upgrades Maintenance & upgrades
– Test & installation of new Test & installation of new equipmentequipment
Winches used for deploymentWinches used for deployment
The Ice Camp (4km offshore)
Schematic view on the deep underwater complex NT200
136
6 m
1.5km
44
5
11
9
12
13
3600 m
100 m 100 m
1 2 3
6 7 8 10
14
18
17
16
15
600 m
10-Neutrino Telescope NT2007-hydrophysical mooring 5-sedimentology mooring
12-geophysical mooring 13-18-acoustic transponders
1-4 cable lines
Anchor
Buoy
NANP’03NANP’03
NT200 running since 1998- - 8 strings with 192 optical modules,- 72m height,- R=21.5m radius, -1070m depth, Vgeo=0.1Mton effective area: S >2000 m2 (E>1 TeV)Shower Eff Volume: ~1 Mt at 1 PeV
“Quasar” photoelectric detector
G= 20-30
The items for NT200
- Low energy phenomena (10 GeV-100 TeV) atmospheric neutrinos and muons- Search for dark matter neutrino signal from WIMP annihilation- Search for exotic particles
magnetic monopoles
- High energy phenomena (100TeV- 1000PeV)
diffuse neutrino flux
neutrinos from GRB HE neutrino sources prompt muons and neutrinos Environmental studies
“Low” energy neutrino search strategy
Atmosphere
p
p
Earth
The neutrinotelescope
10
- 6
At the 1km depth :
We look for upward going muons
Photoelectrons
Amplitude (Chan 12)
Time difference (dt = t52-t53)
t, ns
Atmospheric muons: Calibration BeamAi, ti
atm.
Reconstructed ’s :Cos(zenith) distributionvs. Corsika
cos ( )
Sky plot for upward going neutrino
April1998 - February 2003 years, 1038 days,462 events.
Threshold – 15 GeV
23
Search for WIMP Neutrinos from the Center of the Earth
+ b + b
W + + W -
C + +
Detection area of NT-200 for vertically up-going muonsdetection (after all cuts)
WIMP Neutrinos from the Center of the Earth
Limit on excess neutrino induced upward muon flux 90% c.l. limits from the Earth ( 1038 days NT200 livetime, E > 10 GeV )
1038 days livetime NT200 (1998 -2003)48 evts - experiment73.1 evts - prediction without oscillations56.6 evts - prediction with oscillations 3.6 evts - atm. Muons (backgraund) Systematic uncertainties: 24%
Within statistical and systematic uncertainties 48 detected events are compatible with the expected background induced by atmospheric neutrinos with oscillations.
N= n2 (g/e)2 N = 8300 N g = 137/2, n = 1.33
Event selection criteria:
hit channel multiplicity - Nhi t> 35 ch,upward-going monopole -(zi-z)(ti-t)/(tz) > 0.45 & o
Background - atmospheric muons
Limit on a flux of relativistic monopoles: < 4.6 10-17 cm-2 sec-1 sr-1
90% C.L. upper limit on the flux of fast monopole (1003 livedays)
Search for fast monopoles ( > 0.8)
27
Search for High Energy neutrino (cascades)
NT200
large effective volume
(BG)
Look for events with large number hit channels and for upward moving light fronts.
Number of Cherenkov photons
Nph = 200 (E / 2 MeV) for
E=10 Pev Nph = 1012!!!
The 90% C.L. Limits Obtained WithNT-200 (1038 days)
DIFFUSE NEUTRINO FLUX
(Ф ~ E-2, 10 TeV < E < 104 TeV)
e = 1 2 0 (AGN)
e = 1 1 1 (Earth)
Diffuse flux of e, , : cascades
W-RESONANCE ( E = 6.3 PeV, 5.3 ·10-31 cm2 )
Baikal Фe < 3.3 · 10-20 (cm2 · s · sr · GeV )-1
AMANDA Фe < 5.0 · 10-20 (cm2 · s · sr · GeV )-1
Baikal E2 Ф < 8.1 ·10-7 GeV cm-2 s-1 sr-1
AMANDA E2 Ф < 8.6 ·10-7 GeV cm-2 s-1 sr-1
Vg(NT200)
AMANDA II
Flux of e, , : cascades
Astropart. Phys. 25 (2006) 140
Toward Gigaton Water Detector(KM3 detector on lake Baikal)
2005 year. Upgrade to NT200+ finished
Laser intensity - cascade energy:(1012 – 5 1013 ) puls- (10 – 500) PeV
ExtString 1 ExtString 3 ExtString 2 NT200 Central+Outer Str.
New ShoreCable
100 m
Foto from Mar, 2005, 4km off-shore:NT200+ deployment from 1m thick ice.
Ice – A perfect natural deployment platform
1 10 100 1000 PeV
4 15 23 40 Mton
Total number of OMs – 228 / 11 strings
Instrumented volume – 5 Mt(AMANDA II, ANTARES – 10 Mt)
Detection volume >10 Mt for E>10Pev
- high resolution of cascade vertex and energy neutrino energy
2005: NT200+ - intermediate stage to Gigaton Volume Detector (km3 scale) is commissioned in Lake Baikal
Main physics goal: Energy spectrum of all flavor extraterrestrial HE-neutrinos (E > 100 TeV)
Ultimate goal of Baikal Neutrino Project:
Gigaton (km3) Volume Detector in Lake Baikal Sparse instrumentation:
91 – 100 strings with 12 – 16 OMs (1300 – 1700 OMs) effective volume for >100 TeV cascades ~ 0.5 -1.0 km³
lgE) ~ 0.1, med< 4o
detects muons withenergy > 10 - 30TeV
624m
280m
70m
70m120m
208m
- Basic detector element is NT200+. Under “Real Physics Test“ since 4/2005. -Dedicated R&D for Baikal/km3 – technology starts in 2006. Redesign of some key elements is under consideration.
Issues:
- Optical Module: Quasar vs other? Grouping 2 vs 3? FADC readout? ...- Time synchronization: electrical vs. optical, .... - System architecture: subarray trigger, string controller, data transfer, ...- Auxiliary systems: acoustic positioning, bright laser sources, …- MC design optimization- ...
- Interaction Baikal/km3 KM3NeT : Common activities for a few selected technical issues - could this be useful ? e.g. OMs (design/in-situ tests@NT200+); MC (design; verification); TimeSync.; Auxil.Dev.; …,...
A Gigaton (km3) Detector in Lake Baikal
- Status -
PM selection for the km3 prototype stringPM selection for the km3 prototype stringBasic criteria of PM selection is its effective sensitivity to Cherenkov Basic criteria of PM selection is its effective sensitivity to Cherenkov
light which depends onlight which depends onPhotocathode areaPhotocathode area Quantum efficiency Quantum efficiency Collection efficiency Collection efficiency
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
4 PM R8055 4 PM R8055 (Hamamatsu) (Hamamatsu) и 2 и 2 XP1807 (Photonis)XP1807 (Photonis)were installed to were installed to NT200+ detector (April NT200+ detector (April 2007).2007).
4 PM: central telescope 4 PM: central telescope NT 200;NT 200;2 PM R8055: outer 2 PM R8055: outer string, FADC prototype.string, FADC prototype.
Quasar-370Quasar-370
Quasar-370Quasar-370
Quasar-370Quasar-370
Quasar-370Quasar-370
R8055R8055
XP1807XP1807
PM selection: Underwater tests PM selection: Underwater tests (2007)(2007)
LaserLaser
160…
180 m
Relative effective sensitivities of large area PMsRelative effective sensitivities of large area PMs(preliminary results)(preliminary results)
0 1 2 3 4 5 60,0
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
Rel
ativ
e P
M s
ensi
tiviti
es
PMT number
Relative effective sensitivities of large area PMs R8055/13” , XP1807/12” and Quasar-370/14.6”. Laboratory measurements (squares), in-situ tests (dots).
Smaller size (R8055, XP1807) tends to be compensated by higher photocathode sensitivities.
Design of Prototype string Design of Prototype string
PMT pulses & Power 12 VControl line
Data (Ethernet), Trigger
FA DC
P Csphere
OM4
OM6
OM5
FA DC
OM3
OM1
OM2
OM6
OM4
OM5
OM1
OM3
OM2
PC-104
RS485c onv er
ter
DSL
modem
RS485c onv er
terEth
Sw itc h
Tr iggerc ontro l
VME
Contr
FADC9
101112
FADC5678
FADC1234
Power
Trigger
Multic hannel A mplif ier&Pow er output
PMT
D iv id e r /A m p lif ie r
C O N T R O L L E R O M-M C C 8 0 5 1 F 1 2 4-R S 4 8 5 in te r fa c e-P M T p u ls e c o u n te r-P o w e r (H V , L V ) m o n ito r
H V U N ITP H V 1 2 -2 .0 K
LEDs
L E Dc o n tr o l- A m p l- D e la y
Basic features
String lengths ~300 m
String contains 12…16 OM
Optical modules contains only PM and control electronics
12 bit 200 MHz FADC readout is designed as multi channel separate unit.
Half-string FADC controllers with ethernet-interface connected to string PC unit
String PC connected by string DSL-modem to central PC unit
30
0 m
FADC unit is operating nowin Tunka EAS 1 km2 detector(astro-ph/0511229)
Baikal – GVDBaikal – GVD Schedule Milestones Schedule Milestones
• 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
Overall cost ~ 20 MEuro Detector ~ 16 MEuro
Logistics, including infrastructure ~ 4 MEuro
Acoustic detection of high energy neutrino
Acoustic Detection of High Energy Neutrino
Absorption of sound in water
10mPa
1mPa
Acoustic noise within 22-44 kHz frequency band at different depths Example of bipolar pulse
Listening from top to down
Absorption length of acoustic signal in water
Angular distribution of detected bipolar events
Energy dependence of expected acoustic signal amplitudes from cascades
I.Belolaptikov 54
1. Underwater and underice Cherenkov neutrino detectors is real way to open new window in Universe.
2. In addition to existing intermediate scale underwater/underice neutrino detectors in near future should be constructed a few KM3 Cherenkov arrays.
3. Baikal is complementary to Amanda/IcaCube: location, water (low scattering), reconstruction
4. The Baikal Telescope NT200 is in operation since 1998 and Lake Baikal is one of the most suitable place in the world for deployment of huge KM3 neutrino telescope
5. R&D on Gigaton Volume Detector (km3-size array on Lake Baikal) on the base of experience of NT200+ operation is in progress.
6. New participants and collaborators are highly appreciated, welcome!!!!!!
Summary
The interdisciplinary environmental studies
Length – 720 km,
width – 30-50 km,
depth –1.3-1.64km
20% of fresh water
The water bodyof the lake is
fully oxygenated
Several hundred endemic speciesInhabit all depths
of the lake
B.Koty
Why water is so kind?
Why conditions for life are so good?
These is only thanks to
the high rate of deep-water renewal !!!!!
TMD = 3.9839 - 1.9911∙10-2 ∙ P - 5.822 ∙ 10-6 ∙ P2 - (0.2219 + 1.106 ∙ 10-4 ∙ P) ∙ S
Depth dependence of temperature of
maximum density
Summer profile
Temperature depth dependence in Lake Baikal
Winter profileHomothermy
Epilimnion (0-40 m)Thermocline (2-150 m)Hypolimnion (30m – bottom)
Meter
Instrumental moorings
0 30 60 90 120 150 180 210 240 270 300 330 360Days (2000-2001 from 01 M arch)
0
2
4
6
8
10
12
Tem
per
atu
re19m
25m
77m
90m
127m
182m288m
.
MuchMay
July
The temperature at the near-surface zone
September November January
30 60 90 120 150 180 210 240 270 300 330 360 390Tim e (days from 01.03.2001)
3.3
3.4
3.5
794
3.3
3.4
3.5
996
3.3
3.4
3.5
1198
3.3
3.4
3.5
1259
3.3
3.4
3.5
1309
3.3
3.4
1362
Tem
per
atu
re
June November
Cold intrusionTemperature
decreasedon 0.1 degree
The interdisciplinary environmental studies
• Water dynamic (vertical and horizontal water exchange)
• Biological productivity
• Global climate changes
• Geophysical phenomena
The instruments and methods
• Long-term optical monitoring• 3 - dimensional monitoring of the water
luminescence• 3 - dimensional temperature monitoring• long-term monitoring of geoelectric field• Acoustic tomography • Sedimentology study (in co-operation with
EAWAG, Switzerland)
The ASP-15 instrument.
• а – absorption coefficient,
• b –scattering coefficient,
• Е – photons flux ])(exp[)( 0 xbaExE
])(exp[)( 0 xbaExE
Baikal
Baikal
Optical Properties
Far away from a point like light source E(r) ~ exp(-r/Las)/r
La, m Ls, m Lef, ,m Las,m
Baikal 22 50 0.88 416 18
Antarctic ice 100 3 0.88 25 29
Mediterranean sea 55 55 0.88 458 41
La –absorption lengthLs-scattering length
The luminescence as the instrument to study the dynamic phenomena in Baikal water
• The luminescence which appear as a result of oxidization of organic material in Baikal water was discovered in 1982 year.
• The luminescence matter is produced by biology at shallow depth and then transported to deep layers by water currents, turbulence and due to sedimentation, at the same time matter loss its ability to luminescence .
• The luminescence is a natural tracer for the development of hydrophysical phenomena and an indicator of hydrobiological activity in the Lake Baikal.
Counting rate of FEU-130 versus depth at Neutrino Telescope site in ice cover period.
The photon flux density I(photon cm-2 s-1) = (3.5+/- 1) N
N
Counting rate of an optical module of NT-200 at 1993 -1994 years.
The luminescence is a natural indicator of development of hydrobiological and hydrophysical phenomena in the Lake Baikal.
Counting rate of the 19 optical modules of NT-200 in September1993 year.
10 20 30 40 50 60 70Tim e , h from 00.00 23.09.93
12000
16000
20000
Counting R
ate/
10 ,
Hz
14:36 23.09.93 - 12:51 25.09.93 RUN 1000-1011
2
2
3
1
1
Vertical water motion.• Counting rate of the 3 optical
modules of NT-200 situated• on the same vertical string
• V vert = 2 cm/s !!!!!!!!!
Counting rate of the 3 optical modules of NT-200 situated
• on the same depth on the different strings
7.5 m
Geophysical Mooring
Synthetic rope
Synthetic rope
Electronic box
1000 mCable
Electrode 2
Electrode 1
Anchor
Twisted cable
Twisted cable
Buoy
Buoy
Vertical component of electric field
days
High frequency Ez variations.
Inertial waves15 hours
Low frequency Ez variations.
27 days
Мелозира байкальская - Aulacoseira baicalensis
1950 1960 1970 1980 1990 2000 2010 2020 2030Y e a rs
0
100
200
300
A. b
aica
lens
is n
umbe
rs in
"m
elos
ira
year
s",
thou
sand
cel
ls p
er li
tre
in th
e up
per
0-25
m la
yer
0
100
20019th
20th
21st 22nd
23rd
Sol
ar a
ctiv
ityin
Wol
f's n
umbe
rsSolar activity
Productivity of Aulacoseira baicalensis y = cos(23t/11)
Welcome to Lake Baikal
Thank you!