Rotational state-to-state energy transfer of NH2((A)over-tilde(2)A(1)) in beam-gas condition

The detailed study on the rotational state-to-state energy transfer (RSET) of NH2((A) over tilde (2)A(1)) at a relative translational energy of about 360 cm(-1) has been reported herein, by combining self-breakdown pulsed dc discharge and a photon counting technique. The transferred populations from the parent levels to the daughter levels have been obtained through the spectral simulations. It is clear that the rotational state distributions depend not only on the rotational quantum numbers of the initial and collisionally populated states, but also on the quantum number Ka. It is interesting to find that the probability of RSET behaves differently depending on the rotational quantum numbers of the parent levels, i.e., the exponential angular momentum transfer law (AMT) is preferred with the relatively low rotational levels, while the exponential energy gap law is preferred with the relatively high levels. According to the sudden approximation and the theory of Osborne , the experimental results are explained qualitatively. (C) 1999 American Institute of Physics. [S0021-9606(99)00247-0]