Left panel: p/He ratio as a function of E_k/n, along with BESS98 (Sanuki et al. 2000) and BESS-TeV (Haino et al. 2004) data. The lines show the toy-model calculation without the destruction term (thick solid lines) and with it (thick dotted lines). The black, red and blue lines are respectively modulated to Φ = 0 MV (IS), Φ = 591 MV and Φ = 1109. Left panel: same ratio, but as a function of the rigidity. The data are AMS-01 (AMS Collaboration et al. 2002), ATIC (Zatsepin et al. 2003), CAPRICE 94 (Boezio et al. 1999), and some balloon data (Webber et al. 1987). The three toy-model calculations corresponds to the destruction rate set to zero (solid lines) or to its required value (dotted lines), plus a difference in the spectral index of p and He (dashed lines). In both plots, the normalisation is arbitrarily set to match the data.