Search

The vibrational and rotational population distributions expected of the diatomic species AB just after splitting from the tri-atomic complex [ABC] have been calculated on the basis of the statistical model including the law of angular momentum conservation. It has been shown that the angular momentum possessed by the complex [ABC] exerts considerable influence upon the initial and non-thermal distribution of populations in the vibrational and rotational levels of AB.

A micro-channel plate dynode type image intensifier whose output window is a fibre face plate coated with phosphor on its inner surface has been applied to a low f -number spectroscopic detector for studies of very weak light signals sent from the crossing between an electronic or ionic beam and an atomic or molecular beam. It can reduce long exposures extending over nights for optimum density spectrograms to be obtained in the conventional way, down to scores of minutes and to several seconds. The resolution and sensitivity are both nearly satisfactory, as far as atomic lines, continua, and diatomic band-heads are concerned.

Initial and nonthermal population distributions among the rotational and vibrational levels of the two diatomic species split from a four-atomic collision intermediate have been studied on the basis of the statistical model which ensures that the angular momentum of the whole system is conserved throughout the course of the splitting. A number of curves have been calculated with the aid of an electronic computer, for the initial rotational population distribution (i. r. p. d.) and the initial vibrational population distribution (i. v. p. d.). The i. r. p. d. computed varies considerably, according as the moments of inertia of the diatomic fragments are equal to or different from each other, and the excess energy E possessed by the intermediate is large or small compared with the vibrational quanta of the fragments. On the contrary, the i. v. p. d. computed remains unchanged in most cases, when the vibrational energy is expressed in the unit of E . Some of the population distributions predicted by the stat...

Helium ion impact on H 2 O exhibits quite a different spectrum from that electron-impact on H 2 O gives. In the former, the OH + A , 3 Π→ X , 3 Σ - band-system can be observed in addition to the OH A , 2 Σ + → X , 2 Π. On the contrary, there is no trace of the OH + bands in the latter. These experimental evidences have been obtained by the crossed-beam technique.