THE NO(A (4)PI) STATE - DIRECT PHOTOEXCITATION FROM THE GROUND-STATE

Spectroscopic measurements are made on the (11, 0) band of the NO(a (I I)-I-4-X (II)-I-2) system. The NO is excited by the 208-209 nm output of an excimer-laser-pumped doubled dye laser. The a(v = II) population is transferred by collisions with NO and He to doublet levels, from w hich radiation is seen at 250-260 nm. The doublet and quartet characte r of the lines is distinguishable by the different temporal behavior o f their fluorescence. The lines are assigned using simulated spectra. This study constitutes the first measurement of NO(a-X) line positions .