University of Maryland
Atlantic Building, Room 2400
4:30 PM Monday, April 8, 2013
Coffee, Tea & Snacks 4:15-4:30 PM

Dr. John Mitchell
NASA/Goddard Sapce Flight Center
Measuring Antimatter over Antarctica

Measuring cosmic-ray antimatter and nuclei with a balloon-borne instrument is scientifically important and rewarding, and can be surprisingly exciting. This talk will describe the Balloon-borne Experiment with a Superconducting Spectrometer (BESS) program and share some of the adventure of ballooning in Antarctica. The US-Japan BESS collaboration uses elementary particle measurements to study the early Universe and provide fundamental data on thespectra of light cosmic-ray elements and isotopes. BESS measures the energy spectra of cosmic-ray antiprotons to investigate possible signatures of dark-matter candidates and searches for heavier antinuclei that might reach Earth from antimatter domains formed during symmetry breaking processes in the early Universe. The apex of the BESS program was reached with the Antarctic flight of BESS-Polar II that returned data on 4.7 billion cosmic-ray events in 24.5 days during the 2007-2008 Austral Summer. The flight was terminated on 21 January 2008 in a remote location approximately 1800 km from the US McMurdo Station. The instrument was disassembled and recovered in 2009-2010 with a 13-day deep-field camp. The scientific motivation for the BESS measurements and the results of the BESS program will be discussed, focusing on data from BESS-Polar II.

Sponsored by: Department of Physics and the Institute for Physical Science and Technology, University of Maryland. For information call Catha Stewart at (301) 405-4811 or go to the UMD Space Physics group seminar web site.

There is free parking after 4:00 PM in lot B (the big parking garage across the street from the ATL building). There are a limited number of spaces in lot Q next to the new ATL wing with free parking after 4PM even when there is a basketball game on campus.