Status of the AMANDA and BAIKAL neutrino telescopes

Kinetics of Conversion of Air Bubbles to Air Hydrate Crystals in Antarctic Ice

“…Koci (6) modeled the temperature vs depth at South Pole, using the known surface temperature of -55 C and fixing the temperature at bedrock at the pressure melting temperature. In situ measurements (7) by AMANDA at depths from 800 to 1000 m gave temperatures that agreed with Koci's model to within 0.3 C.…”

“…Based on the measurements on bubbles at Vostok and Byrd, can we predict the concentration of bubbles as a function of depth in ice at the South Pole? The last question is of great importance to the AMANDA project (14,15), which involves implanting long strings of large photomultiplier tubes at great depths in South Pole ice in order to detecť Cerenkov light from muons produced in high-energy neutrino interactions. Only if the array is located in bubble-free ice can the direction of a muon be precisely determined by measuring the arrival times of thě Cerenkov wavefront at each of the phototubes.…”

“…To show this I carried out a diffusion calculation that takes into account the time and temperature as a function of depth for the Vostok and Byrd sites. I converted depth to time for each core using age vs depth data in (7). I assumed that there is no nucleation barrier and that the long time-scale for the disappearance of bubbles is due to slow diffusion.…”

“…With D 0 as a fitting parameter, I found that D 0 = 2100 cm 2 s −1 gave acceptable fits to both the Vostok data and the Byrd data (9) on bubble concentration as a function of depth. (15). The curves show the results of applying the diffusion model to the three sets of data.…”