Measurement of sound speed vs. depth in South Pole ice for neutrino astronomy
arXiv:0909.2629 · doi:10.1016/j.astropartphys.2010.01.012
Abstract
We have measured the speed of both pressure waves and shear waves as a function of depth between 80 and 500 m depth in South Pole ice with better than 1% precision. The measurements were made using the South Pole Acoustic Test Setup ({SPATS}), an array of transmitters and sensors deployed in the ice at South Pole Station in order to measure the acoustic properties relevant to acoustic detection of astrophysical neutrinos. The transmitters and sensors use piezoceramics operating at 5-25 kHz. Between 200 m and 500 m depth, the measured profile is consistent with zero variation of the sound speed with depth, resulting in zero refraction, for both pressure and shear waves. We also performed a complementary study featuring an explosive signal propagating from 50 to 2250 m depth, from which we determined a value for the pressure wave speed consistent with that determined with the sensors operating at shallower depths and higher frequencies. These results have encouraging implications for neutrino astronomy: The negligible refraction of acoustic waves deeper than 200 m indicates that good neutrino direction and energy reconstruction, as well as separation from background events, could be achieved.
14 pages, 7 figures
References in corpus (19)
- Neutrinos from propagation of ultra-high energy protons
- Muon Track Reconstruction and Data Selection Techniques in AMANDA
- RICE Limits on the Diffuse Ultra-High Energy Neutrino Flux
- Detection of Atmospheric Muon Neutrinos with the IceCube 9-String Detector
- Experimental Study of Acoustic Ultra-High-Energy Neutrino Detection
- Simulation of Ultra High Energy Neutrino Interactions in Ice and Water
- Attenuation of acoustic waves in glacial ice and salt domes
- In situ radioglaciological measurements near Taylor Dome, Antarctica and implications for UHE neutrino astronomy
- Oceanic Ambient Noise as a Background to Acoustic Neutrino Detection
- Simulation of a Hybrid Optical/Radio/Acoustic Extension to IceCube for EeV Neutrino Detection
- Measurement of acoustic properties of South Pole ice for neutrino astronomy
- Status and First Results of the Acoustic Detection Test System AMADEUS
- HADES - Hydrophone for Acoustic Detection at South Pole
- Acoustic noise in deep ice and environmental conditions at the South Pole
- Feasibility of acoustic neutrino detection in ice: Design and performance of the South Pole Acoustic Test Setup (SPATS)
- NEMO-\onde: a submarine station for real-time monitoring of acoustic background installed at 2000 m depth in the Mediterranean Sea
- Acoustic detection of astrophysical neutrinos in South Pole ice
- Acoustic detection of high energy neutrinos in ice: Status and results from the South Pole Acoustic Test Setup
- Sensor development and calibration for acoustic neutrino detection in ice
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- SUSY Renormalization Group Effects in Ultra High Energy Neutrinos
- Background studies for acoustic neutrino detection at the South Pole
- Acoustic particle detection - from early ideas to future benefits
- Design and performance of the South Pole Acoustic Test Setup
- Status and recent results of the South Pole Acoustic Test Setup
- Acoustic detection of ultra-high energetic neutrinos - a snap shot
- Acoustic transient event reconstruction and sensitivity studies with the South Pole Acoustic Test Setup
- Neutrino Detection, Position Calibration and Marine Science with Acoustic Arrays in the Deep Sea