Dissociative Recombination of CH+ Molecular Ion Induced by Very Low Energy Electrons

We used the multichannel quantum defect theory to compute cross sections and rate coefficients for the dissociative recombination of CH+ initially in its lowest vibrational level vi+=0 with electrons of incident energy below 0.2 eV. We have focused on the contribution of the 2 2 pi state which is the main dissociative recombination route at low collision energies. The final cross section is obtained by averaging the relevant initial rotational states (Ni+=0,MIDLINE HORIZONTAL ELLIPSIS,10) with a 300 K Boltzmann distribution. The Maxwell isotropic rate coefficients for dissociative recombination are also calculated for different initial rotational states and for electronic temperatures up to a few hundred Kelvins. Our results are compared to storage-ring measurements.