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Isabella Amore VLV T08, Toulon, France 22-24 April 2008 International Workshop on a Very Large Volume Neutrino Telescope for the Mediterranean Sea Results from the NEMO-Phase 1 experiment Isabella Amore for the NEMO Collaboration INFN-LNS 22-24 April 2008, Toulon Palais Neptune Conference Centre
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Isabella Amore VLV T08, Toulon, France 22-24 April 2008 NEMO Phase 1 25 km E offshore Catania 2000 m depth TSS Frame Buoy Junction Box e.o. connection e.o. cable from shore Shore laboratory, Port of Catania e.o. cable 10 optical fibre, 6 conductors NEMO mini-tower (4 floors, 16 OM) Mini-Tower unfurled 300 m Junction Box 15 m Mini-Tower compacted
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Isabella Amore VLV T08, Toulon, France 22-24 April 2008 NEMO Phase 1 Deployment Connection in the frame Connection of the JB Connection of the Mini-Tower Deployment of the Mini-TowerDeployment of the JB
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Isabella Amore VLV T08, Toulon, France 22-24 April 2008 The NEMO Mini-Tower Tower Base Module Floor 1 Floor 2 Floor 3 Floor 4 Backbone e.o. cable Tensioning ropes Break-out Optical modules Floor control module FLOOR 4 conductors 4 fibers
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Isabella Amore VLV T08, Toulon, France 22-24 April 2008 Mini-Tower Slow Control Instrumentation FCM 4 th Floor ADCP 3 rd Floor 2 nd Floor 1 st Floor Base tower CTD C-Star Compass Tilt meter FCM Hydrophone Acoustic Doppler Current Profile Sea Current Light Transmissivity in Water Conductivity Temperature Pressure Acoustic Positioning
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Isabella Amore VLV T08, Toulon, France 22-24 April 2008 Acoustic Positioning System A commercial acoustic positioning system was used (ACSA). Acoustic poisitionig board with DSP onboard: acoustic signal analysis underwater detection time sent to shore to recover hydrophone position. Mini Tower with 4 floors 8 acoustic receivers and a monitoring station Clock based on GPS Time Beacon Signal detection time Acoustic positioning PC Acoustic positioning board 200 kHz digitization Beacon on Tower Base Distances between beacons were calculated with ROV and GPS Monitoring Station Beacon pulses Hydrophone Times are synchronized
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Isabella Amore VLV T08, Toulon, France 22-24 April 2008 Acoustic Positioning System Resolution ~15 cm 350 m TOF=TOA hy -TOE beac TOE beac =TOA ms -TOF beac-ms TOF beac-ms = D(beac-ms)/v sound Hydrophone Monitoring Station
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Isabella Amore VLV T08, Toulon, France 22-24 April 2008 Acoustic Positioning Data Beacon Tower Base Northing Easting Beacon LBL Tower Position Floor 2 Floor 3 Floor 4 From 23/01/07 to 03/02/07 From 24/02/07 to 20/05/07 Average Current Direction South After Deployment Tower Base No Acoustic Position Data until 23 January 2007
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Isabella Amore VLV T08, Toulon, France 22-24 April 2008 Acoustic Positioning Data Each frame represents the average floors positions of a day Positions of hydrophones in the Tower Floor 4 Floor 3 Floor 2 Floor 1
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Isabella Amore VLV T08, Toulon, France 22-24 April 2008 Instrumentation Data: Sea current Magnitude (mm/sec) Direction (Degree) ADCP Floor 4 Mean Direction ~180° (SOUTH)
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Isabella Amore VLV T08, Toulon, France 22-24 April 2008 Instrumentation Data: Floor 1 Depth CTD Floor 1 Depth Floor 1 80 m Sea bed
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Isabella Amore VLV T08, Toulon, France 22-24 April 2008 PMT Data Acquisition and Transmission Optical modules Optical Fiber + DWDM multiplexing Floor Control Module Interface (on Shore) Data GPS Time + controls The NEMO electronics and telecommunication system permits point-to-point data transmission from sea to shore using synchronous data transmission. This allows the whole detector to be in phase and synchronised (~1 nsec, data transmission delay known) Time Calibration Board Floor Control Module Board Slow Control Interface Board FEMBoard 200 Msample/s
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Isabella Amore VLV T08, Toulon, France 22-24 April 2008 DAQ system on shore FCMI Windows Linux Cable PC Monitor DM - RC (Trigger) DATA MANAGER: Instrumentation Data Acoustic Positioning OM Rates RUN CONTROL: OM Data On Line Monitoring Trigger On-Line OMs Data Storage
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Isabella Amore VLV T08, Toulon, France 22-24 April 2008 PMT Rates The average measured rates are about 80 kHz for PMTs on floors 2, 3 and 4 Rates measured from 10–20 Jan 07 Floor 4 PMT
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Isabella Amore VLV T08, Toulon, France 22-24 April 2008 Post-Trigger Data 1- Simple Coincidence (SC) Coincidence between 2 close hits in the same storey ∆T CS ≤ 20 ns 2- Floor Coincidence (FC) A SC in coincidence with a hit recorded by a PMT located in the opposite site of the storey ∆T FC ≤ 200 ns 3- Charge Shooting (CS) A hit exceeding a charge threshold 4- Random Trigger (RT) Open randomly a window of 1 ms with periodicy 1-10 s OM DATA Features: Signal Digitization Sampling ~ 200 MHz Time resolution ~ 5 ns Charge Threshold ~ 0.4 p.e. Trigger Window ~ 4 μs DATA ANALYZED: 23-24 January ~10 Hours of Data TRIGGER On-Line 4 Seeds Implemented Charge distribution ~10 p.e. 1 p.e.
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Isabella Amore VLV T08, Toulon, France 22-24 April 2008 Hit Selection and Event Reconstruction chain Procedure steps for the track reconstruction: Detector Level 1 Trigger Causality filter Reconstruction Events having at least 7 offline trigger seeds and a charge > 0.5 p.e. Event Selection Hit Decompressed Time resolution ~1 nsec Data from the Acoustic positions 1- Simple Coincidence (SC) Coincidence between 2 close hits in the same storey ∆T CS ≤ 20 ns 2- Floor Coincidence (FC) Coincidence between 2 hits recorded at the opposite ends of a same storey ∆T FC ≤ 200 ns 3- Charge Shooting (CS) A hit exceeding a charge threshold of 2.5 p.e. Only the hits that survived at the CF go to reconstruction Calibration of Post-Trigger Data ~10 p.e. 1 p.e.
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Isabella Amore VLV T08, Toulon, France 22-24 April 2008 Reconstructed Atmospheric Muon Tracks Run 15 Event 11 Date 23 Jan 2007 H. 20:21 Hit = 17 Hit Selected = 14 Hit Reconstructed = 12 θ= 168° Trigger Seed = 17 SC = 4 FC = 5 CS = 8 Likelihood RED = - 8,3 1685 Tracks Recontrsucted for the analysed data set (23-24 Jan 2007)
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Isabella Amore VLV T08, Toulon, France 22-24 April 2008 Reconstructed Atmospheric Muon Tracks Run 17 Event 38 Date 24 Jan 2007 H. 02:20 Hit = 24 Hit Selected = 17 Hit Reconstructed = 16 θ= 132° Trigger Seed = 23 SC = 3 FC = 14 CS = 6 Likelihood RED = - 6,9 1685 Tracks Recontrsucted for the analysed data set (23-24 Jan 2007)
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Isabella Amore VLV T08, Toulon, France 22-24 April 2008 Atmospheric Muon Simulation for the Mini-tower Detector Average OM positions measured on 23 January with APS Generator: MUPAGE 4·10 7 Atmospheric Muon Generated LiveTime = 4.08·10 4 sec ~ 10 hours Optical Properties: Light absorption length measured at NEMO Test-Site Optical Background evaluated from data (~ 80 kHz) Front-End Electronics : Simulation of Mini-Tower electronics L0 Trigger : L0:NEMO Phase-1 Trigger On-Line Reconstruction: RECO Event Selection: Same processing for detector data and simulation L1 Trigger :
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Isabella Amore VLV T08, Toulon, France 22-24 April 2008 Comparison with the simulations Rate Data tracks reconstructed = 0.047 ± 0.001 Hz Rate Simulated tracks reconstructed = 0.044 ± 0.001 Hz Atmospheric muon angular distribution Likelihood Distribution
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Isabella Amore VLV T08, Toulon, France 22-24 April 2008 Conclusions Slow control data analysis almost completed : - Optical module positions recovered for all the data set : resolution ~ 15 cm - Tower movements well understood - Oceanographical Instrumentation data analyzed Optical modules data under analysis: - OM rates as a function of time already analyzed (~ 80 kHz) - Atmospheric Muon Tracks reconstruction performed for the 23-24 Jan 2007 data set 1685 tracks reconstructed Rate Data tracks reconstructed = 0.047 ± 0.001 Hz - Angular distribution of atmospheric muons (preliminary) - Good agreement with simulation
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