THE ORIGIN OF SO2 AFTERGLOWS AS REVEALED BY MAGNETIC-FIELD EFFECTS

The chemiluminescence intensity in the low pressure diffusion flame of the CS2+O/N2 system was found to be considerably affected by external magnetic fields. The emitter in the flame was identified as the main emitter in the SO2 afterglow. The measurements of the field strength dependence, collisional effect, and spectral distribution of the magnetic field effect revealed the major emitter as the SO2 in the C state. External magnetic fields were also found to quench fluorescence remarkably emitted from the vibronic levels just below the predissociation threshold in the C state. From the observed vibrational-level, field-strength, and pressure dependences of the magnetic quenching, it became evident that the major emitter of chemiluminescence in the flame could be assigned to the SO2 molecule in the vibronic levels located at about 800 cm-1 below the predissociation threshold in the C state.