Production of ground state OH following electron impact on H2O

Laser-induced fluorescence (LIF) measurements of OH(X (2)Pi) production following electron impact on water have been carried out over an energy range from threshold to 300 eV. Data have been made absolute using existing measurements of OH(X) production via dissociative attachment. The cross section reaches a maximum value of 2.1 X 10(-16) cm(2) at an energy of 75 eV. Dipole-allowed processes are shown to dominate the production of OH(X) particularly via the A(B-1(1)) repulsive state, though significant population of higher rotational levels is demonstrated, indicating the relevance of other channels as in photodissociation. (C) 2001 American Institute of Physics.