Cosmic ray 1H and 2H spectra from BESS 98

The Balloon-borne Experiment with a Super-solenoidal Spectrometer (BESS) instrument has been flown annually from Lynn Lake Manitoba since 1993. The instrument has been upgraded several times to improve its performance. The instalment flown in 1998 was able to detect 2H clearly between 0.13 and 1.78 GeV/n as a result of improvements made on the time-of-flight (TOF) system. The BESS 98 data were analyzed to obtain the ratio and absolute fluxes of 1H and 2H over this energy range. The results were compared with different cosmic ray propagation models and their implications regarding their propagation history are discussed in this paper.