Cosmic-ray lithium and beryllium isotopes in the PAMELA-experiment

The PAMELA space experiment was launched on the 15th of June 2006 from the Baikonur cosmodrome. The scientific objectives addressed by the mission are the measurement of the antiprotons and positrons spectra in cosmic rays, the hunt for antinuclei as well as the determination of light nuclei fluxes from hydrogen to oxygen in a wide energy range and with high statistics. The apparatus comprises a time-of-flight system, a magnetic spectrometer (permanent magnet) with an silicon-microstrip tracking system, an imaging calorimeter built from layers of siliconmicrostrip detectors interleaved with plates of tungsten, an anti-coincidence system, a shower tail scintillator-counter and a neutron detector. The instrument in its detector-combination is also capable to identify isotopes, using the rigidity information from the magnetic spectrometer together with the time-of-flight measurement or with the multiple dE/dx measurement in the calorimeter. In this paper details about the analysis method and new results of the isotopic ratios of lithium and beryllium with increased statistics will be presented.