In this project in the Experimental Physical Chemistry program of the Chemistry Division, R.S. Berry will study Penning detachment, a process in which a free, gaseous negative ion releases an electron as a result of a collision with an electronically excited neutral atom or molecule. The project is a collaboration of two institutions, The University of Chicago and the Heyrovsky Institute for Physical Chemistry in the Czech Republic. The Chicago experiments will be done with laser excitation of neutrals, while the Prague experiments will use electron impact excitation and subsequent electron energy analysis. Initially atomic ion and neutral collisions will establish the proof of principal. Later experiments will move to simple molecules as donors and targets. %%% The Penning detachment process, which is analogous to Penning ionization, is little studied but represents a new type of interaction between gas phase species which may play an important role in chemical vapor deposition or other plasma processes, such as take place in the upper atmosphere. As such, it has wide-ranging implications, from possibly improved manufacturing processes to a better understanding of ionospheric phenomena.
