OBSERVATION OF THE FLUORESCENCE POLARIZATION OF ATOMIC FRAGMENTS FROMROTATIONAL RESOLVED PREDISSOCIATION

The effect of molecular rotation on the degree of polarization of the fluorescence emitted by H-atoms that are obtained by photopredissociat ion of H-2 into H(n = 3) + H(1S) has been observed. The H-2 molecules are excited to predissociative excited states with a well defined rota tional quantum number by absorption of a photon in the wavelength rang e of 720-750 Angstrom. The molecular rotational motion is clearly seen to reduce the polarization. In one case the polarization vanishes, wh ich is attributed to a P(1) rotational line of a (1) Sigma - 1 Sigma t ransition, which cannot be explained classically. Quantum mechanical c alculations with relatively simple expressions and explicit values of the polarization of atomic fluorescence are presented.