$CN B^{2}\Sigma^{+}$ ALIGNMENT FOLLOWING VUV DISSOCIATION OF ICN

Dispersed CN $B^{2}\\Sigma^{+}-X^{2}\\Sigma^{+}$ photofragment fluorescence polarization anisotropies measured following ICN dissociation at 157.6 nm vary widely and apparently erratically with emission wavelength, and cannot be converted directly to CN B rotational alignments because of spectral congestion. A flexible linear regression technique is used to extract $CN B^{2}\\Sigma^{+}$ alignments for $v^{\\prime}=0, 1, 2$, and 3. These alignments range from -0.31 to nearly 0.2 and vary smoothly with N' for each $v^{\\prime}$. A model is presented to estimate partial channel CN $B (v^{\\prime}=0)$ product populations, and a discontinuity in the experimental $v^{\\prime}=0$ alignment is considered.