Translational energy spectroscopy of collisional neutralization-reionization processes

Abstract

The translational energy change, Δ T[M +] nr, undergone by fast ions in neutralization-reionization collisions was measured for a number of projectiles and collision gas combinations. The dependence of Δ T[M +] nr on the vibrational energy content of 8 keV [H 2] +√ ions was investigated and discussed. From the variation in Δ T[M +] nr for three [C 2H 4O] +√ and three [C 3H 6O] +√ isomers it could be established which of the neutral counterparts were stable and which of them rearranged before reionization. For example, neutralized [CH 2CHOH] +√ was proposed to rearrange via a 1,2 H shift into CH 3COH. The mechanism of the collisional reionization was investigated for various target gases. The observed translational energy changes indicated that electron transfer from the neutral projectile to the reionization target gas was not an important process in our experimental conditions.