Modeling Quantum Kinetics in Ion Traps: State-changing Collisions for OH+((3)Sigma(-)) Ions with He as a Buffer Gas

作者：Gonzalez Sanchez L; Wester R; Gianturco F A^*

来源：ChemPhysChem, 2018, 19(15): 1866-1875.

DOI：10.1002/cphc.201800119

• inelastic collisions
• intermolecular potentials
• collisionally inelatic rates
• rotational relaxation times
• molecular dynamics in cold traps

We present quantum scattering calculations for rotational state-changing cross sections and rates, up to about 50K of ion translational temperatures, for the OH+ molecular ion in collision with He atoms as the buffer gas in the trap. The results are obtained both by using the correct spin-rotation coupling of angular momenta and also within a recoupling scheme that treats the molecular target as a pseudo-(1 sigma+ ) state, and then compares our findings with similar data for the OH-(1 sigma+ ) molecular partner under the same conditions. This comparison intends to link the cation behaviour to the one found earlier for the molecular anion. The full calculations including the spin-rotation angular momenta coupling effects have been recently reported (L. Gonzalez-Sanchez and R. Wester and F.A. Gianturco, Mol.Phys.2018, DOI 10.1080/00268976.2018.1442597) with the aim of extracting specific propensity rules controlling the size of the cross sections. The present study is instead directed to modelling trap cooling dynamics by further obtaining the solutions of the corresponding kinetics equations under different trap schemes so that, using the presently computed rates can allow us to indicate specific optimal conditions for the experimental setup of the collisional rotational cooling in an ion trap for the system under study.

• 出版日期2018-8-7