The Quantum World of Cold Electron Collisions

Abstract

Collisions between electrons and molecules at thermal energy play a key role in the chemistry and physics of plasmas, ranging from those in space to the chemically active plasmas used for thin film and microcircuit fabrication. However, until recently, data for electron-molecule interactions below a few hundred millielectronvolts impact energy (a few thousand kelvin) were very sparse. Our experiments, using a high-resolution synchrotron photoionization source of electrons, have opened up this low-energy field. We present recent results which reveal some of the striking quantum scattering events which take place as long-wavelength, low-energy electrons encounter molecules, choosing H(2), N(2), benzene, halobenzenes, methanol, ozone, and chlorine dioxide as examples.