The continuous spectrum produced by the radiative dehyphen;excitation of metastable atoms by atom impact is an example of molecular continuummdash;continuum transitions. It is shown that if the upper molecular state has a deep attractive well and the lower state is repulsive, the continuous spectrum will show bandlike structure similar to that obtained in boundmdash;continuum transitions from high vibrational states. The analysis is applied to the radiative dehyphen;excitation of He(21S) by He, which gives rise to the ``600hyphen;Aring; bands.'' The structure and temperature dependence of these bands are well explained as bandlike continuummdash;continuum emission. Bandlike continua observed in other rare gases are briefly discussed in terms of the molecular states involved.
展开▼
