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A.TsirigotusA.TsirigotusHellenic Open Hellenic Open

UniversityUniversity

NNeutrino eutrino EExtended xtended SSubmarine ubmarine TTelescope with elescope with OOceanographic ceanographic

RResearchesearch

The NESTOR O.M.The NESTOR O.M.

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• Hamamatsu PMT R2018-03 (15”)

• Benthos spheres

• μ-metal cage

• power supply

Single p.e. conditions

The Detector

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dc/dc converterPMT base

Silica

Al disk

Hamamatsu PMT inside the BENTHOS sphere

Pressuregauges

The NESTOR Optical Module

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Extensive Lab tests

On single p.e. conditions

Detector Preparation

Optical Modules

L.E.D.Reference

Relative timing

                                

                   

Pulse Height (mV)

LED Calibration Run

Time Difference in PMTs Response

Time (ns)

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Detector Preparation

Attenuation Correction

                                

                  

Reference waveform

Coaxial cable

Electronic delay lines and amplifier

Fourier Transform-ComparisonFrequency (MHz)

Frequency (MHz)

Ph

ase

(rad

)A

mp

litu

de

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Data from a depth of 4000 mSingle PMT Rates

Trigger: ≥4fold Coincidence

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Waveform ReconstructionWaveform Reconstruction

Sample Offset (ADC counts)Sample

Off

set

(AD

C c

oun

ts)

Before the F.F.T. and the attenuation corrections

After the F.F.T. and the attenuation corrections

Rise Time

16 ns

9 ns Double pulse separation

Time (ns)

Vol

tage

(m

V)

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single p.e.

LED Run

single p.e. pulse height distribution

two p.e.s pulse height distribution

dark current pulse height distribution

sum of the above

Data from a depth of 4000 m

PMT Pulse Height Distribution

Calibration

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Calibration Data Analysis

Calibration Database Quality Histograms

LED Calibration Data

Gain Monitors

Data from a depth of 4000 mCalibration Run

Time Difference (ns)

Nu

mb

er o

f E

ven

tsN

um

ber

of

Eve

nts

Time Difference (ns)

<Δt>: 0.6 ± 0.1 ns

σ : 3.3 ± 0.1 ns

<Δt>: 0.2 ± 0.1 ns

σ : 3.3 ± 0.1 ns

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Data from a depth of 4000 mCalibration Run