Reply to "Comments on the Simulation of the Passage of Fast Electrons in Water"

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The curves for stopping power presented by LaVerne and Mozumder in their Comments (1) are distinguished qualitatively not only from the curves we obtained (2), but also from those of Paretzke et al. (3). It should be noted that LaVerne and Mozumder indicate that the curves presented in Ref. (1) are from Ref. (4), but Ref. (4) does not contain them. These new curves are considerably different quantitatively from the curves of their work (5), which is discussed by us in Ref. (2). But the qualitative difference with Refs. (2, 3) has been retained, so the discussion of cross sections used is quite valid. We agree with LaVerne and Mozumder (1) that the approximation used in their calculation is more accurate than that corresponding to the Bethe formula, because the parameters in their formula for stopping power depend upon an electron energy. But in the energy region Ee 100 eV. We also agree that the ionization and excitation cross sections of Paretzke and Berger (6) are not directly experimental. They are synthetic and were obtained as a generalization of experimental and theoretical data. But from this it by no means follows that they are more approximate than the directly experimental ones. We actually used the data of Zeiss and co-workers (7) to calculate total excitation and ionization cross sections and partial ionization cross sections in the vapor phase as LaVerne and Mozumder (1) recommend [see our previous work (8), where details of the procedure of simulation are given]. For calculation of the partial excitation cross sections in the vapor phase we used the data of Kutcher and Green (9) because similar data are not presented in the explicit form in Ref. (7). In the Monte Carlo simulation of stopping power we used the ionization cross section (10) in which the exchange effects were taken into account. The exchange was not taken into account for the energy loss in the liquid phase less than 25 eV. But in the case of electrons with Eo > 100 eV it does not necessarily result in inaccuracies. If we compare the average energy loss AE in our work (2) with that of Pimblott et al. (4), who used improved cross sections, we obtain practically complete agreement (see Table I). It is interesting to note that if we calculate the stopping power according to the formula