The Balloon-borne Experiment with a Superconducting Spectrometer (BESS) was flown eight times from Lynn Lake, Manitoba, Canada between 1993 and 2002. The performance of the instrument was improved with essentially each successive flight, and precise spectral measurements of cosmic-ray hydrogen and helium isotopes were made during different phases of the solar modulation. This paper presents the measured isotopic spectra for the most recent solar maximum in 2000 and compares the results with previous measurements and with the theoretical prediction from the Reacceleration model. Both 1H and 2H spectra are consistent with the propagation calculation with the solar modulation parameter 1500 MV. The total He (3He + 4He) flux is in good agreement with the same modulation parameter. Fluxes of 3He and 4He require slightly higher modulation parameter.
|Number of pages||4|
|Publication status||Published - 2007|
|Event||30th International Cosmic Ray Conference, ICRC 2007 - Merida, Yucatan, Mexico|
Duration: 2007 Jul 3 → 2007 Jul 11
|Conference||30th International Cosmic Ray Conference, ICRC 2007|
|Period||07/7/3 → 07/7/11|