Report on New Technologies (Working Group 7), Acoustics
Report on New Technologies (Working Group 7), Acoustics
Justin Vandenbrouckefor David Waters
Justin Vandenbrouckefor David Waters
Acoustic neutrino revival, past few years:- sensor optimization and calibration- signal simulation- tests at accelerator beams- real arrays at Bahamas, UK, Mediterranean
In addition to WG 7, see L. Thompson talk and G. Riccobene poster
energyconcentrated
here
Consider two
regimes:
• SPATS (South
Pole)T = -51 ºC,f >10 kHz,a ≈ 8.6 km
or
• Ross Ice Shelf T ≈ -28 ºC,f < 1 kHz,a ≈ 500 m
P. B. Price
Acoustic array on Ross Ice Shelf for GZK neutrinos?
Advantages: • Flatness: acoustic waves can propagate by hopping along
firn-air interface. • Cheap: deploy at the surface; no drilling required
• Close to McMurdo; more accessible than South Pole
Disadvantages: At T ≥ -28ºC, only waves with f <1 kHz have a > 500 m,and very little energy goes into such low-frequency waves.
P. B. Price
Coincident effective volumes + event ratesfor IceCube (I), an optical extension (O),
and combinations with surrounding A + R arrays
(GZK events/yr)
astro-ph/0512604
Resolution studies
1) Acoustic slow radio/optical hits give exact emission time for acoustic
1 R + 4 A: 2 m vertex res.
2) Acoustic pancake gives neutrino direction
<1° from acoustic pancake
J. Vandenbroucke
Simulations of an Acoustic DetectorT. Karg, PhD Thesis, astro-ph/0608312
(2006)
effective volume and energy threshold strongly dependent on detection threshold of sensors
) design and test efficient signal
processing algorithmsrate of correlated
neutrino-like background events is not known,
only random coincidences assumed
) measure with AMADEUS at different length
scales
200 acoustic modules in Vinstr. = 1 km3
Kay Graf
Instrumentation Line with
3acoustic storeys
(+SPY II) (deployment
foreseen first half 2007)
3 more acoustic storeys in
another line(plans to be
finalized)
AMADEUS: ANTARES Modules for Acoustic Detection Under the Sea
ANTARES storey
2 m
Kay Graf
Discussion: Hybrid approachIs it desirable?
No: 1) Length and energy scales different, don’t hamstring one just for overlap
Yes: 1) Seeking rare events, want redundancy 2) Overcome systematics, improve resolution
Much optimization to do, e.g. mazimize total or coincident event rate?
Suggestion:1) Build small independent arrays to understand each technique
(possibly in same location), be ready to optimize and expand2) Deciding and optimizing will require fully understanding each
technique and discovering some events