“…On the other hand, higher LET contaminants tend to raise the calculated cross section above the true value. We believe that some of the rather unusual observations described in References [1][2][3][4], and emphasized in the previous section, may be due, at least in part, to impurities in the ion beams. However, a detailed analysis of the precise effects of beam impurities in these studies is not possible based solely upon the limited information provided in the literature.…”