The 2007 BESS-Polar Scientific Flight in Antarctica

The Balloon-born Experiment with a Superconducting Spectrometer (BESS), aiming to search for antiparticles/antimatter in the cosmic radiation, successfully carried out the second scientific flight over Antarctica in 2007/2008 (BESS Polar-II), in the solar minimum period. The newly developed BESS Polar-II spectrometer including the solar-cell power supply system worked well during the flight, and more than 4.6 billion cosmic ray events were recorded for 24.5 days. This report describes overview of the scientific flight.