Acoustic detection of neutrinos in bedrock

Abstract

We propose to utilize bedrock as a medium for acoustic detection of particle showers following interactions of ultra-high energy neutrinos. With the density of rock three-times larger and the speed of sound four-times larger compared to water, the amplitude of the generated bipolar pressure pulse in rock should be larger by an order of magnitude. Our preliminary simulations confirm that prediction. Higher density of rock also guarantees higher interaction rate for neutrinos. A noticeably longer attenuation length in rock reduces signal dissipation. The Pyhäsalmi mine has a unique infrastructure and rock conditions to test this idea and, if successful, extend it to a full-size experiment.

Doppler Effect and Acoustic Trails of Neutrinos

“…Recently, the scientific community has been discussing the possibility of detecting neutrino traces not only in water or ice, but also in the solid medium of the earth's crust (Trzaska et al, 2019). Figure 3 shows the result of comparing bipolar pulses generated by ultra-high energy particles: in rock -A (red line) and in water -B (blue line).…”

Possibilities for Underground Physics in the Pyhäsalmi mine

“…3, the explored area covers the volume of about 1 km 3 reaching from the depth of around 1300 m down to 2500 m. The total length of the new boreholes is 3.5 km. It has been proposed [24] to deposit strings of microphones into the boreholes in a similar fashion it has been done or is going to be done by the ANTARES/AMADEUS [25] and the KM3NeT [26] collaborations for the purpose of acoustic detection of particle showers following interactions of ultra-high energy neutrinos. This type of measurement in the rock have never been tried or even proposed before.…”