David Waters could not be here

due to Viviane Waters,born August 22

Congratulations!

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

SAUND (ocean)

ACOUSTIC

P. B. Price, 1996 Astropart. Phys.

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

South Pole Acoustic Test Setup

3 strings in 3 IceCube holes, Jan 2007

Stephan Hundertmark

SPATS tested in frozen lake, Northern Sweden

Stephan Hundertmark

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