Transcript Статус и планы Байкальского нейтринного

I.Belolaptikov behalf BAIKAL
collaboration
SINP MSU, July 7, 2012
Site properties
Summer
expedition
Winter
expedition
Day temperature
>250 km3
Depth – 1360 m with flat bed at distance > 3 km from
the shore allows > 250 km3 instrumented volume !
Site properties
 Strong ice cover during ~2 months:
- Telescope installation, maintenance, upgrade and rearrangement
- Installation & test of a new equipment
- All connections are done on dry
- Fast shore cable installation (3-4 days)
 Water optical properties:
- Absorption length – 22-24 m
- Scattering length – 30-50 m
- Moderately low background in fresh water
March 2011
cable
tractor with
ice cutter
ice slot
cable layer
Shore cable deployment
Water properties allow detection of all flavor neutrinos with
high direction-energy resolution!
1998 - NT200
2005 - NT200+
Quasar
photodetector
(=37cm)
NT200: 8 strings (192 OMs)
Height x  = 70m x 40m,
Vinst=105m3
Effective area: 1 TeV~2000m²
Eff. shower volume: 10 TeV~ 0.2 Mton
~ 3.6 km to shore,
1070 m depth
NT200+ = NT200 + 3 outer strings
(192+36 OMs)
Height x  = 210m x 200m,
Vinst = 5106m3
Eff. shower volume: 104 TeV ~ 10 Mton
Gigaton Volume Detector (GVD) in Lake Baikal
R&D status
Objectives:
- km3-scale 3D-array of photodetectors
- flexible structure allowing an upgrade and/or a
rearrangement of the main building blocks (clusters)
- high sensitivity and resolution of neutrino energy, direction
and flavor content
Central Physics Goals:
- Investigate Galactic and extragalactic neutrino “point
sources” in energy range > few TeV
- Diffuse neutrino flux – energy spectrum, local and global
anisotropy, flavor content
- Transient sources (GRB, …)
- Dark matter – indirect search
- Exotic particles – monopoles, Q-balls, nuclearites, …
Structure elements of the detector
12-16 OM
String
2-4 Sections
Cluster
8 Strings
R ~ 60 m
To the shore
String section, 12 OMs
Section
L~ 705 m
OM
GVD desing
Configuration
10368 Optical modules,
216 Strings: 48 OM/Str., 4 Sec./Str.
27 Clusters: 8 Str/Cluster
Geometry:
Z = 15 m – distance between ОМ on string
R = 60 m – cluster radius
H = 300 m – distance between clusters
Instrumented volume: ~1.5 km3
Depth: 600-1300 m
Muons: (E>1 TeV):
Seff ~ 0.3–1.8 km2 ; δθmed < 0.5o ;
δlg(E/Em) ~0.4
10368 OMs
2304 OMs
Cascades: (E>10 TeV):
Veff ~0.4–2.4 km3; δ(E/Esh) ~25%; δθmed~ 5o
10368 OMs
2304 OMs
GVD prototype strings 2009 - 2010
Prototype string
2009
Prototype string
2010
PMT:
Photonis
XP1807
PMT:
Hamamatsu
R7081HQE
6 OM
Hamamatsu
R8055
6 OM
NT200+
In-situ tests of basic elements of
GVD with prototypes strings
(2009...2010)
Investigation and tests of new
optical modules, DAQ system,
cabling system, triggering
approaches
( LED
Laser Muons)
7 OM
Hamamatsu
R8055
3 OM
Prototype string: muon reconstruction
- Performance of time measuring systems.
- Reliability of calibration methods.
- Efficiency of background suppression.
Selected sample of 2010 string data:
- Trigger condition: >3 hit OMs
- PMT noise: ~15kHz
Muon track reconstruction:
Noise suppression procedure:
The time difference between the
pulses of any pair of OMs should
be smaller than the light
propagation time.
Zenith angular distributions of
experimental and MC-simulated
events after cuts
Cluster 2011 technical design
Optical modules
The OMs house photomultipliers of different types:
16 PMT R7081HQE (Hamamatsu, 10 inch)
5 PMT R8055
(Hamamatsu, 13 inch)
3 PMT XP1807
(Photonis, 12 inch
Strings
• Size reduced section:8 optical modules, CM and SM.
• CM (Central module): 2ADC board (8 chan.), Master .
• SM (Service module): Control and connection to the
cluster DAQ center.
• Acoustic positioning system, 3 modules on each string.
(accuracy ~2 cm, measurements each 30 sec)
Cluster DAQ center
Cluster DAQ center provides the string triggering, power
supply, and communication to shore.
Communication lines
Connection between the strings and cluster DAQ center:
1.2 km copper cable. Connection to shore – optical cable
6 km.
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Optical cable 2011
BAIKAL-GVD prototype cluster: 2011
NT200+
communication
lines
248 “live” days
NT200+
Sketch of prototype cluster, neutrino telescope
NT200+, and communication lines locations.
In April 2011, a prototype cluster of GVD was installed in Lake Baikal.
− 3 vertical strings with 8 optical modules each.
− Vertical spacing between OMs is 10 m.
− Horizontal distance between strings is 40 m.
− Depths is 1205 – 1275 m.
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Present and nearest future
2012
3-strings, first full
scale GVD string
(24 ОМ)
Data taking since
April 2012
2013
Detector with 3 full scale
GVD strings
DAQ
DAQ
DAQ
DAQ
2014-2015
Cluster (8 strings)
DAQ
DAQ
106 м3
4106 м3
Plans
Preproduction:
2014–2015. Full scale GVD cluster, 8 strings (192 Oms)
Production (preliminary)
 2014–2018:
12-14 Clusters
 2018–2020: Full scale detector ( 27 clusters )
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Summary
1. Preparation towards a km3-scale Gigaton Volume Detector in Lake
Baikal is currently a central activity:
- In-situ tests of the prototype string shows good performance of
basic string elements (2009-2010).
- A prototype GVD cluster with 3 strings was installed (2011) and
shows stable work for whole year.
- New technology underwater optical cable was mounted (2011).
- Full scale GVD string(24 OMs) with 2 “short” strings(6 OM) taking
data since April 2012.
2. Full scale GVD cluster (~200 OMs) is expected at 2014-2015.
GVD Technical Design Report was prepared (2011):
http://baikalweb.jinr.ru/GVD/
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