Formation of negatively-charged cluster ions in thermal energy collisions with state-selected rydberg atoms

Lifetime of C2Cl4− ions produced by nondissociative electron attachment to C2Cl4

The lifetimes of long-lived C2Cl4(-) ions formed by Rydberg electron transfer in K(np)/C2Cl4 collisions are investigated using a Penning ion trap. Measurements at high n, n > or = 30, show that low-energy electron attachment to C2Cl4 leads to the production of C2Cl4(-) ions with a broad range of lifetimes that extends up to at least 1 ms. This is attributed to capture by molecules in different initial vibrational states. At low n, internal-to-translational energy transfer in postattachment interactions between the product K+ and C2Cl4(-) ions becomes important and leads to a substantial increase in ion lifetimes.

Rydberg electron transfer to SF6: Product ion lifetimes

The lifetimes of SF6- ions produced by Rydberg electron transfer in K(np)SF6 collisions at high n, n greater or similar to 30, are examined using a Penning ion trap. The data point to the formation of ions with a range of lifetimes that extends from approximately 1 to greater or similar to 10 ms. Sizable numbers of ions remain in the trap even 40 ms after initial injection and at least part of this signal can be attributed to radiative stabilization. Measurements of free low-energy electron attachment to SF6 in the trap show that the product ions have lifetimes similar to those of SF6- ions formed by electron transfer in high-n collisions.