LES and RIS spectra measured from polycrystalline ice films that were prepared under the following conditions: (a) adsorption of (0.5 BL) onto a -ice film (8 BL) at 70 K. (b) 10 min after warming the sample in (a) at 110 K. (c) Adsorption and ionization of HCl (0.1 ML) onto a -ice film (8 BL) at 130 K. (d) Adsorption of (0.6 BL) onto the sample in (c) at 70 K. (e) After the sample in (d) was warmed to 110 K at a rate of and kept at this temperature for 1 min. The LES spectral region is shown in the magnified scale for all spectra. The beam energy was 30 eV.
Kinetic data showing the changes in , HDO, and surface populations with time for ice films with externally provided protons. The ice films were prepared in a similar structure to that shown in Fig. 1(d), i.e., adsorption of (0.5 BL) on a HCl (0.1 ML)/ (8 BL) film. The samples were heated to the indicated temperature at a rate of and then maintained at this temperature during the kinetic measurement. The kinetic origin was set to be the time that the sample reached this temperature. The error bars indicate the signal intensity fluctuations in repeated measurements. The incident energy of the beam was 30 eV. The lines indicate the numerical solutions of kinetic equations [Eq. (A6) in Appendix] fitted to the experimental data.
Kinetic measurement of , HDO, and populations on the pure ice film surface. The ice samples were prepared to have the same structure as that in Fig. 1(a), i.e., (0.5 BL) on a -ice film (8 BL). The lines indicate the numerical solutions of kinetic equation (A6). The experimental details are the same as those described in Fig. 2, except for the sample temperature.
Arrhenius plot of the H/D exchange rate coefficients on ice film surfaces. The rate coefficients and the associated error bars are obtained by using the refined kinetic analysis (see text).
First-order kinetic fitting to the change in HDO surface concentration with time for ice films with externally provided protons (solid symbols) and for pure ice films (open symbols). The straight lines indicate the rate expression shown in Eq. (A3). The kinetic data are the same ones as those presented in Figs. 2 and 3.
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