University of Maryland
Atlantic Building, Room 2400
4:30 PM Monday, May 12, 2014
Coffee, Tea & Snacks 4:15-4:30 PM

Nicolas Picot-Clemente
IPST, University of Maryland
Measurement of Galactic Cosmic-Ray Hydrogen and Helium Isotopes with BESS-Polar II

The Balloon-Borne Experiment with a Superconducting Spectrometer (BESS-Polar II) flew successfully over Antarctica during 24.5 days in December 2007 through January 2008 during a period of minimum solar activity. BESS-Polar II is configured with a solenoidal superconducting magnet and a suite of precision particle detectors. It can accurately identify hydrogen and helium isotopes among the incoming cosmic-ray nuclei with energies from 0.2 up to about 1.5 GeV/n. The long duration of the flight, and the good stability of the detectors, improved by a factor of 5 the number of cosmic-ray events previously recorded with BESS-Polar I, reaching about 4.7 billion collected particles. Energy spectrum of cosmic-ray hydrogen and helium isotopes have been measured with the BESS-Polar II instrument with unprecedented accuracy. The isotope flux and secondary-to-primary ratio measurements provide important information to better understand the propagation history of cosmic rays in the Galaxy. The results will be presented and compared to various propagation models.

Sponsored by: Department of Physics and the Institute for Physical Science and Technology, University of Maryland. For information call Victoria 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.