Dissociative excitation of odd sextet levels of the manganese atom in the e-MnCl2 collisions

The dissociative excitation of odd sextet levels of the manganese atom in collisions between slow electrons and manganese dichloride molecules was studied experimentally. The cross sections for the population of the metastable a ⁶ D levels (the lower levels of the laser transitions) by cascade transitions have been determined. It is established that for the z ⁶ F° and z ⁶ D° levels, the cross sections for both the dissociative and direct excitation, Q _m and Q _a , respectively, differ only slightly in absolute value. For the x ⁶ P° levels, the ratio Q _a /Q _m amounts to 9–11, but for the upper laser levels it is much larger: 33 for the z ⁶ P° level and 240 for the y ⁶ P° level.