INVESTIGATION OF COOLING OF N-2(C-3-PI(U),V',J') IN A SUPERSONIC DISCHARGE

An investigation of the cooling of N-2((CIIu)-I-3,v',J') in a corona s upersonic discharge of pure nitrogen is presented. Ideal gas calculati ons illustrate the essentials of expansion cooling and radiative and c ollisional relaxation. The spectra of the N-2 (CIIu)-I-3-->B3IIg emiss ion are presented. An indirect method (computer program) arrives at th e rotational population distributions of the upper state. Notably, non -Boltzmann population distributions are characteristic of emitting N-2 ((CIIu)-I-3,v',J) in the free jet expansion. The disparate roles playe d by radiative and collisional relaxation of metastables in the postno zzle gas flow are discussed.