Байкальский нейтринный эксперимент Г.В.Домогацкий 1 23 декабря 2009г. Москва

1.Институт Ядерных Исследований РАН, Москва, Россия 2.Иркутский Государственный Университет, Иркутск, Россия 3.Научно Исследовательский Институт Ядерной Физики МГУ, Москва, Россия 4. DESY-Zeuthen, Zeuthen, Germany. 5. Объединенный Институт Ядерных Исследований, Дубна, Россия 6. Нижегородский Государственный Технический Университет, Нижний Новгород, Россия 7.С. Петербургский Государственный Морской Технический Университет, С. Петербург, Россия 8. Курчатовский Институт, Москва, Россия Коллаборация БАЙКАЛ

A NT200+/Baikal-GVD (~2017) N N KM3NeT (~2017) /IceCube Amanda/IceCube(~2011) ANTARES 59 Strings in operation

2009 August 20Lepton Photon 2009 Per Olof Hulth High Energy neutrino telescopes (optical) 2009 August 20 4 Lepton Photon 2009 Per Olof Hulth

NT200: 8 strings (192 optical modules ) Height x  = 70m x 40m, V inst =10 5 m 3 Effective area: 1 TeV~2000m² Eff. shower volume: 10 TeV~ 0.2 Mton Quasar photodetector (  =37cm) NT200+ = NT outer strings (36 optical modules) Height x  = 210m x 200m, V inst = 5  10 6 m 3 Eff. shower volume: 10 4 TeV ~ 10 Mton Status of NT200+ LAKE BAIKAL ~ 3.6 km to shore, 1070 m depth NT200+ is operating now in Baikal lake (~10 months/yr. persistent data taking)

2009 August 20Lepton Photon 2009 Per Olof Hulth ANTARES Installation: Junct.Box - Dec 2002 Line 1 - March 2006 Line Dec 2007 Line May Optical modules 12 lines 25 storeys / line 3 PMTs / storey Installation: Junct.Box - Dec 2002 Line 1 - March 2006 Line Dec 2007 Line May Optical modules 12 lines 25 storeys / line 3 PMTs / storey <- 40 km 2500 m depth 2009 August 20 6 Lepton Photon 2009 Per Olof Hulth

2009 August 20Lepton Photon 2009 Per Olof Hulth 2009 August 20 IceCube timeline In the ice: 2005: 1 string 2006: 9 strings 2007: 22 strings (publishing) 2008: 40 strings (analyzing) 2009: 59 strings (running) (includes 1 DeepCore string) Planned: 2010: 77 strings (includes 6 DeepCore strings) 2011: 86 strings (includes 6 DeepCore strings) 15-year design lifetime IceCube timeline In the ice: 2005: 1 string 2006: 9 strings 2007: 22 strings (publishing) 2008: 40 strings (analyzing) 2009: 59 strings (running) (includes 1 DeepCore string) Planned: 2010: 77 strings (includes 6 DeepCore strings) 2011: 86 strings (includes 6 DeepCore strings) 15-year design lifetime Deployed strings 7 Lepton Photon 2009 Per Olof Hulth

ПЛАН Регламентные работы на детекторе НТ200+ Регламентные работы на детекторе НТ200+ Разработка и испытания прототипа гирлянды глубоководных регистрирующих модулей и элементов системы управления кластера детектора НТ1000 Разработка и испытания прототипа гирлянды глубоководных регистрирующих модулей и элементов системы управления кластера детектора НТ1000 Набор и анализ данных детектора НТ200+ Набор и анализ данных детектора НТ200+ Работа над проектом гигатонного детектора Работа над проектом гигатонного детектора НТ1000 (BAIKAL-GVD) НТ1000 (BAIKAL-GVD)

Scientific Program A tmospheric neutrinos D iffuse neutrino flux WIMP from the Earth Center N eutrinos from GRB WIMP from the Sun NT200 Magnetic Monopoles Atmospheric muon background WIMPs in the Sun WIMPs in the Earth Center + Local neutrino sources, Diffuse neutrino flux

Neutrinos from WIMPs annihilation in the Sun and Earth Sun Baikal NT200: , hard Baksa n’199 7 AMANDA- II’2001, hard MACR O’199 8 Super- K’2001 IceCube- 22’2007, hard Earth Limits on muon flux - 48 events selected expected from atm. muons with oscillations and without osc. 90% c.l. limit on excess muon flux (m  > 100 GeV):  < 3x10 3 km -2 yr 1 90% c.l. limit on excess muon flux (m  > 100 GeV):  < 1.2x10 3 km -2 yr -1 Events within diff. cones around nadir No excess of events above atm. BG Sun-mismatch angle distribution 1008 live-days data sample 1038 live-days data sample

GRB Neutrino Search 11 Search for direction + time correlations with 303 GRBs observed by BATSE in , using the upward-going muon data sample. Time window: (t GRB + T s) - (t GRB -5s) Half angle of observation cone: Ψ = 5 o Observed number of events – 1 event Expected number of bg. events – 2.7 events SK Baikal NT200 Amanda-II “Green’s function” Upper Limits on GRB neutrino fluence (model independent)

ClasterStr. section m GVD - Preliminary design Layout: ~ 2300 Optical Modules, 96 Strings, 12 Clusters String comprises 24 OMs, which are combined in 2 independent Sections Cluster contains 8 strings Instrumented volume: 0.4 – 0.6 km 3 Detection Performance Cascades ( E>100 TeV): V eff ~0.3 – 0.8 km 3 δ(lgE) ~0.1, δθ med ~ 4 o Muons ( E>10 TeV): S eff ~ 0.2 – 0.5 km 2 δθ med ~ 0.5 o -1 o

Optimisation of GVD configuration (preliminary) Parameters for optimization: Z – vertical distance between OM R – distance between string and cluster centre H – distance between cluster centres Muon effective area R=80 m R=100 m R=60 m The compromise between cascade detection volume and muon effective area: H=300 m R = 60 m Z = 15 m Trigger: coincidences of any neighbouring OM on string (thresholds 0.5&3p.e.) PMT: R7081HQE,10”, QE~0.35

GVD – R&D ( ) GVD - Key Elements and Systems: - Optical Module - FADC-readout system - Section Trigger Logics - Calibration - Data Transport - Cluster Trigger System, DAQ - Data Transport to Shore OM 12 OMs2 Sections8 Strings Shore SectionStringCluster

GVD prototype string (2008 – 2009) BEG PC SM NT200+ with experimental string String communication center Optical module In-situ tests of basic elements of GVD measuring system with prototypes strings

Basic parameters of prototype string String length: 110 m Number of Optical Modules: 12 Number of Sections: 2 Number of FADC channels: 12 PMT: Photonis XP1807 (12”) : 6 Hamamatsu R8055(13”) : 6 FADC Time Window: 5  s FADC frequency: 200 MHz Data analysis in progress now 1.Monitoring of the optical module operation. 2.Test the string operation with LED and LASER. Experimental material: April – Jun 2009

Cluster DAQ center Cluster of strings 8 Strings String – 2 sections (2×12 OM) Cluster DAQ Centre: - PC-module with optical Ethernet communication to shore (data transmission and cluster synchronization) - Trigger module with 8 FADC channel for the measure of string trigger time; - Data communication module – 8 DSL-modems, modem data flaw up to 7 Mbit/s for 1 km. - Power control system Calibration system Two Lasers Synchronization – common signal “Acknowledgement” for all strings. GVD – R&D ( )

K din ~10 7 The new generation Baikal Optical Module PM: XP1807(12”), R8055(13”) ‏, R7081HQE(10”) QE ~0.24 QE ~0.2 QE~0.35 HV unit: SHV12-2.0K,TracoPower OM controller: monitoring, calibration, and PMT control; Amplifier: K amp = 10 BEG PMT 1 AmplifierFADC 1 90 m coax. cable OM PMT 12 AmplifierFADC m coax. cable … BEG (FADC Unit): - 3 FADC-board: 4-channel, 12 bit, 200 MHz; - OM power controller ; - VME controller: trigger logic, data readout from FADC, and connection via local Ethernet From the analogue signal to digital data (wave-form) GVD – R&D ( ) OM, Front-end Electronics Measuring channels

String Section – basic cell of the Cluster Section consist of: - 12 Optical Modules - BEG with 12 FADC channels - Service Module (SM) with LEDs for OM calibration, string power supply, and acoustic positioning system. Trigger: coincidences of neighbouring OM (thresh. ~0.5&3 p.e.) expected count rate ~ 100 Hz Communication : DSL-modem: expected dataflow ~0.5Mbit/s (only time intervals containing PMT pulses are transmitted) GVD – R&D ( )

Time resolution of measuring channels (in-situ tests) LED flasher produces pairs of delayed pulses. Light pulses are transmitted to each optical module (channel) via individual optical fibres. Delay values are calculated from the FADC data. Measured delay dT between two LED pulses LED1 and LED 2 pulse amplitude Example of a two-pulse LED flasher event (channel #5) LED1 LED2 dT (Expected)=497.5 ns = ns = 1.6 ns

Time accuracy of measuring channels In-situ test with Laser Time accuracy  T  (time resolution) & (accuracy of time calibration with LED flasher) LASER 110 m OM#7 OM#8 OM#9 OM#10 OM#11 OM#12 OM#1 OM#2 OM#3 OM#4 OM#5 OM#6 97 m r1r1 r2r2 Differences between dT measured with Laser and expected dT in dependence on distances between channels dr  T distribution on channel combination  T < 3 ns Test with LASER  T = dT EXPECTED = (r 2 -r 1 )  c water dT LASER - time difference between two channels measured for Laser pulses (averaged on all channel combinations with fixed (r 2 -r 1 ))

Schedule and Cost: >2006 Activity towards the Gigaton Volume Detector Prototype String ( test of GVD key elements and systems) 2010 Technical Design Report Preparatory Phase, Prototype of Cluster (in-situ test) Fabrication (OMs, cables, connectors, electronics) Construction ( ) GVD Overall cost ( without personnel, contingency, overhead ) ~ 25 M€ Detector ~ 20 M€. Logistics, including infrastructure ~ 5 M€

Physics with cascades Neutrino Flux Composition (flavor content) Energy spectrum: Global anisotropy (extragalactic sources) Local anisotropy (Galactic plane) Point sources (complimentary to muons) Transient sources (GRB, …): time + space correlation with  -rays – relax the cuts Flux composition from astrophysical sources at Earth: ~ 1:1:1 e : E ~ E cas  : E ~ E  +E cas (contained events)  : E ~ E cas

Monitoring of Optical Module operation OM temperature PMT voltage OM monitoring parameters: - PMT high voltage; - PMT count rate; - Temperature; - OM low voltages: 12 V, 5 V, -5 V … OM3 OM5 Example of PMT voltage monitoring : Example of PMT count rate monitoring