Determination of the stopping cross-sections of N2, H2, CH4, C4H10 and C3H6 using alpha particles in the range 1 . 3--4 . 2 MeV.

The stopping cross-sections of N2, H2, CH4, C4H10 and C3H6 have been measured using natural alpha particles from a 238Pu source, with facilities to vary the energy in the range 1.3--4.2 MeV. The work is the extension of measurements made earlier, using C2H4 as the absorber, which showed discrepancies in comparison with results of other authors. The comparison is continued with the results presented here and brief comments made on the degree of agreement obtained.