David Yu with Michael Stamatikos and Dr. Paolo Desiati

UW-Madison Department of Physics

The Antarctic Muon and Neutrino Detector Array (AMANDA) is a telescope designed to detect high-energy muons and neutrinos.  It consists of 677 light detectors buried between 500 and 1500 meters under the surface of the Antarctic ice sheet, at the South Pole.  When a neutrino strikes an ice molecule, the interaction creates a high-energy muon traveling faster than the speed of light in ice.  The muon emits a cone of blue light as it passes through the ice.  AMANDA detects this light and reconstructs the path of the muon and the original neutrino. 

AMANDA's principle objective is to search for high-energy neutrino sources throughout the universe, astrophysical phenomena such as supernovae, active galactic nuclei, and gamma ray bursts.  The majority of the muons passing through AMANDA, however, originate from cosmic ray interactions in the atmosphere.  Since muons can only travel up to a few kilometers through the earth, AMANDA can filter out these atmospheric muons by looking through the earth towards the northern hemisphere.  The quantity of atmospheric muons passing through the detector, however, makes AMANDA ideal for studying muon generation in the atmosphere. 

Atmospheric muon flux data from 178 gamma ray burst events distributed evenly throughout AMANDA's live time in 1998 were studied.  The atmospheric muon flux varied by about 10% during a 227-day period.  Analysis of this variation reveals a positive correlation between atmospheric muon flux and atmospheric temperature.