S E Tzamarias Hellenic Open University Neutrino Extended

S. E. Tzamarias Hellenic Open University Neutrino Extended Submarine Telescope with Oceanographic Research Readout Electronics DAQ & Calibration

NESTOR TOWER

The Detector Single p. e. conditions • Hamamatsu PMT R 2018 -03 (15”) • Benthos spheres • μ-metal cage • power supply

Read. Out Electronics & DAQ Chain

Ti-Sphere Electronics House Keeping Board PMT control Calibration Beakon control PMT HV monitor Power Supply monitors Environmental monitors Floor Board PMT pulse sensing Majority logic event triggering Single & coincidence rate scaling Waveform capture & digitization Data formatting & transmission FPGA & PLD reprogramming Shore Laboratory Signal transmission & Control Power supply PMT signal transmission low voltage supply (24 V) control and monitoring signal transmission

Floor Board PMT Signal Capture & Digitization PMT pulse sensing Majority logic event triggering Single & coincidence rate scaling Waveform capture & digitization Data formatting & transmission FPGA & PLD reprogramming 5 ATWDs Input: 12 PMT signals Delay lines Configuration parameters PLD Trigger Logic & Communication FPGAs

The LED Calibration System 20 m Frequency • Gain monitoring • Timing • Free running Calibration Trigger • Adjustable Trigger frequency • Adjustable LED’s light output Duration Light amplitude

Extensive Lab tests On single p. e. conditions Detector Preparation Calibration at the Lab L. E. D. Relative timing Reference Time Difference in PMTs Response LED Calibration Run Pulse Height (m. V) Time (ns)

Amplitude Detector Preparation Attenuation Correction Frequency (MHz) Phase (rad) Fourier Transform-Comparison Frequency (MHz) Reference waveform Electronic delay lines amplifier and Coaxial cable

LED Angular Profile Number of P. E. s / sr /Light Pulse Laboratory measurements Estimated Angular Profile of the LED emission in water Parameterized Angular Profile of the LED emission in air PMT Geometrical Factor: 3. 46 · 10 -4 Transmission Factor: 0. 72 Angle (Degrees)

DAQ Architecture to the floor board Delete Data Storage Data Files Event samples Offline fast analysis Monitor

Online Software Shore Board Downloads the FPGAs & PLD of the Floor Board Broadcasts the 40 Mhz clock Receives Data from the Floor Board Transmits Data to the Run Control System

Real Time Monitor Environmental • Thermometers • Hygrometers • Compass • Inclinometer/Accelerometer • Pressure meter Electrical Event samples • PMT High Voltage etc Monitor Digitization & DAQ Performance • Digitized waveforms • PMT rates • Trigger rates • DAQ status

Real Time Monitors Sample 448 ns

During deployment 15

Offset (ADC counts) Waveform Reconstruction Voltage (m. V) Sample Offset (ADC counts) Rise Time 16 ns 9 ns Double pulse separation Time (ns) Before the F. F. T. and the attenuation corrections After the F. F. T. and the attenuation corrections

Waveform Reconstruction Hit Definition Data Quality Histograms DST Production Event by Event Sampling Interval Variation (Constant Temperature) RMS=0. 006 ns ADC Counts 40 MHz Clock Waveform Capture Software to Hardware Trigger Time Difference (arbitrary time offset) Sample σ=0. 7 ns Time (ns)

Data from a depth of 4000 m Calibration using the natural radiactivity (K 40) Calibration 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 Calibration Run Calibration Data Analysis Number of Events Calibration Database Quality Histograms Gain Monitors σ : 3. 3 ± 0. 1 ns Time Difference (ns) Number of Events LED Calibration Data <Δt>: 0. 6 ± 0. 1 ns <Δt>: 0. 2 ± 0. 1 ns σ : 3. 3 ± 0. 1 ns Time Difference (ns)

Data from a depth of 4000 m Calibration Run

Data from a depth of 4000 m Single PMT Rates Trigger: ≥ 4 fold Coincidence

Data from a depth of 4000 m Trigger Studies Data Collected with 4 fold Majority Trigger Thresholds at 30 m. V Trigger Rate (Hz) Experimental Points Total Charge inside the Trigger Window (1/4 P. E. ) Preliminary M. C. Estimation (Atmospheric muons + K 40 ) Coincidence Level

Data from a depth of 4000 m Trigger Studies Data Collected with 4 fold Majority Trigger Total Charge inside the Trigger Window (1 P. E. ) Trigger Rate (Hz) Thresholds at 120 m. V Preliminary Experimental Points M. C. Estimation (Atmospheric muons + K 40 ) Coincidence Level