LIF Excitation Spectrum of NH₂ Cooled in the Supersonic Jet

The fluorescence excitation spectrum of NH₂ in the supersonic jet has been measured in the wavelength range of 530-570nm using dye laser pumped by an excimer.The NH₂ radical was produced in discharge of NH₃/Ar.Comparing with the spectrum given by S.Mayama et al.⁵，the∏（0,10,0）subband is in good agreement,and the rotational temperature is estimated to be about 20K.The ∏（1,6,0）subband was obtained also.However,the∑（0,11,0）subband was found showing the vibrational temperature was not cooled sufficiently.