Isotope and Electric Field Effects in Dissociative Recombination ofD3+

The cross section for dissociative recombination of vibrationally cold ${\mathrm{D}}_3^{+}$ has been measured at the ion storage ring CRYRING. The rate constant at 300 K, $\alpha =2.7\mathrm{}\times {10}^{-8\mathrm{}}{\mathrm{cm}}^3{\mathrm{s}}^{-1\mathrm{}}$, is a factor of 4.3 smaller than the corresponding value for ${\mathrm{H}}_3^{+}$ measured earlier in CRYRING. An electric field of 30 V/cm was introduced in the electron-ion interaction region. This had no measurable effect on the dissociative recombination cross section. This suggests that the cross sections measured in storage rings for ${\mathrm{H}}_3^{+}$ and its isotopic variants can be directly compared with theoretical results once such results become available.