QUANTITATIVE SPECTROSCOPY OF THE NH TRANSITIONS -TO-1)-A((1)DELTA,UPSILON-LESS-THAN-OR-EQUAL-TO-4) AND R-EQUAL-TO-1)-B((1)SIGMA(-LESS-THAN-OR-EQUAL-TO-2) WITH HN3 LASER PHOTOLYSIS AS THE NH(A) SOURCE(),UPSILON)

For the photodissociation HN3(X) + hnu(248 nm) --> NH(a,upsilon'') + N 2(X), the population ratios of the various states of NH(a,upsilon'') w ere determined. For upsilon'' = 4, a lower limit of NH(a,upsilon'' = 4 )/NH(a,0 less-than-or-equal-to upsilon'' less-than-or-equal-to 4) grea ter-than-or-equal-to 0.002 was found. The population ratios NH(a,upsil on'')/NH(a,0 less-than-or-equal-to upsilon'' less-than-or-equal-to 4) determined previously remain: 0.32, 0.47, 0.17, and 0.038 for upsilon' ' = 0, 1, 2, and 3, respectively. The relative transition probabilitie s for NH(c,upsilon'' = 0,1) <-> NH(a,0 less-than-or-equal-to upsilon'' less-than-or-equal-to 4) and NH(c,upsilon' = 0,1) <-> NH(b,upsilon'' = 0-2) were determined. The spectroscopic constants of NH(a) were impr oved: omega(e) = 3332.37 +/- 0.63, omega(e)x(e) = 76.03 +/- 0.55, omeg a(e)y(e) = 0.84 +/- 0.17, and omega(e)z(e) = 0.055 +/- 0.02 cm-1.