A merging-beams technique was used to determine cross sections for the reaction

H_{2}^{+}

H_{2}

→

H_{3}^{+}

+ H as a function of interaction energy

W

. Cross-section measurements at

W

were accompanied by measurements at 1 eV so that we obtained ratios of cross sections,

\frac{Q_{W}}{Q_{1}}

. These ratios were determined for

0.1 eV \leq W \leq 10 eV

. Some information about the reaction was also obtained for

W \leq 0.03

eV. An absolute cross section was determined for

W = 1

eV. Its estimated error is considerably larger than errors associated with the cross-section ratios. Gioumousis and Stevenson (GS) predict a linear dependence of the cross section on

W^{- \frac{1}{2}}

. On a

\frac{Q_{W}}{Q_{1}}

versus

W^{- \frac{1}{2}}

plot, a straight line can be fitted, within experimental error, to our values for

0.1 eV \leq W \leq 1 eV

. This line is in fair agreement with that predicted by GS. On either side of this range, however, our ratios fall below the

W^{- \frac{1}{2}}

fit. Between 5 and 7 eV our results indicate that, within experimental error,

\frac{Q_{W}}{Q_{1}}

vanishes. On the high-energy side, such a falloff could perhaps be explained by a spectator stripping model. Our cross-section ratios are in general agreement with those obtained from a tandem mass-spectrometer experiment by Giese and Maier, and in rather poor agreement with the results of a single-state mass-spectrometer experiment by Reuben and Friedman. Lower

W' s

were obtained with the merging-beams technique than with the mass-spectrometer methods.

Publications with shared reference:

0 publications found