Development of combined sensors for UHE neutrino detection

Development of combined sensors for UHE neutrino detection Alexander Enzenhöfer ARENA 2010 Nantes, 29. 06. - 02. 07 2010

Outline • Basic considerations • Concept of an Opto-Acoustical Module • Prototype and Test • Conclusion • Work in progress Alexander Enzenhöfer, ARENA 2010, 02. 07. 2010 1

Basic considerations to deep-sea neutrino detection • Mechanics Feedthrough problematic, possible source of errors → Use combined module to reduce feedthrough and electronics, e. g. DAQ, positioning • Methods Large number of sensors/volumes needed → Combination of complementary detection techniques • Calibration Dynamic environment requires monitoring of sensor position → Combine positioning of the sensor module with acoustic particle detection Alexander Enzenhöfer, ARENA 2010, 02. 07. 2010 2

Work at the ECAP AMADEUS • acoustic particle detection test setup • acoustic techniques ANTARES • optical neutrino telescope KM 3 Ne. T • optical sensors • acoustics calibration Combine optical/acoustical sensors with acoustics for: • calibration (primary) • marine science • acoustic detection Alexander Enzenhöfer, ARENA 2010, 02. 07. 2010 3

Concept of a combined Opto-Acoustical Module Optical Module: Acoustic Module: • • PMT integrated into pressure resistant housing Acoustic sensors integrated into pressure resistant housing Alexander Enzenhöfer, ARENA 2010, 02. 07. 2010 Opto-Acoustical Module (OAM): • PMT and acoustic sensor integrated into pressure resistant housing 4

Acoustic Module • Developed at the ECAP • 3 Acoustic Modules integrated in AMADEUS • Acoustic sensor glued to the inside pressure resistant housing • Acoustic sensor protected against of a environmental influences • No additional mechanical structures • No additional feedthrough • Show good results for storey positioning Alexander Enzenhöfer, ARENA 2010, 02. 07. 2010 5

Possible disadvantage resulting from combination • Design dependent angular acceptance • Electronic interference • Module power supply (supply/generation of different voltages inside the module) • PMT HV supply • PMT operation and piezo operation • Interface water–glass–piezo • complex signal path through the glass sphere • coupling of the piezo to the glass Alexander Enzenhöfer, ARENA 2010, 02. 07. 2010 6

Prototype of an OAM Combine: • High voltage power supply (ANTARES) • Piezo-ceramic and preamplifier equivalent to Acoustic Module to build prototype: • Additional acoustic sensor in Optical Module (totally unshielded) • Number/Position of the acoustic sensor depending on module design Alexander Enzenhöfer, ARENA 2010, 02. 07. 2010 7

Acoustic Module: Angular acceptance crane glass sphere water surface sensor (coupled) emitter “equator” steel rods steel frame lead weight Distance 0. 5 m Alexander Enzenhöfer, ARENA 2010, 02. 07. 2010 8

Acoustic Module: Angular acceptance J = 0 o J φ Angular acceptance: ~ ± 70 deg Alexander Enzenhöfer, ARENA 2010, 02. 07. 2010 ch 0 9

Recorded noise spectra (sensor totally unshielded) Alexander Enzenhöfer, ARENA 2010, 02. 07. 2010 10

Recorded noise spectra (sensor totally unshielded) Integrated PMT influence RMSnoise ≈ 5 x RMStyp. sea-state Alexander Enzenhöfer, ARENA 2010, 02. 07. 2010 11

Conclusion • • Ideally installation of more than one Acoustic sensor per module • Significant influence of PMT signal generation on acoustic sensor Influence of HV generation is limited to the frequency range (f > 90 k. Hz) not relevant for acoustic particle detection • Influence only local in frequency domain In current design (worst case with no electromagnetic shielding) no real drawback for positioning but for acoustic detection the design has to be improved Alexander Enzenhöfer, ARENA 2010, 02. 07. 2010 12

Work in progress • Simulations • Simulations of different sensor geometries to • improve sensitivity • increase angular acceptance Sound propagation and signal generation Input admittance • Frequency [Hz] Alexander Enzenhöfer, ARENA 2010, 02. 07. 2010 13

Work in progress • Design of an adapted preamplifier • Improvement of electromagnetic shielding • Tests • Study influence of acoustic sensor on PMT operation • Tests under real conditions Alexander Enzenhöfer, ARENA 2010, 02. 07. 2010 14