二极管激光探测法研究高振动NO_2与NH_3振动传能

Diode Laser Probing of NH_3ν_2 Vibrational Mode Excited by Relaxation of Highly Vibrational Exited NO_2

用高分辨、高速、高灵敏度的二极管激光探测法研究了高振动激发的NO2分子与NH3分子的振动能量转移，YAG532um倍频光作为NO2的激发光源，红外二极管激光（约10μ）探测NH3ν2模被激发振转能级的时间分辨的吸收光谱.实验得到NO2与NH3气压比为1：5，1：1，2：1和5：1时NH3（0100；7；k）的激发速率分别为9．28、6．42、5．05和3．65×10－1ms－1·Pa－1.在NH3压力为133Pa时，有大约6％的高振动激发NO2能量转移到NH3ν2振动模，其它大部分转移到NH3的转动和平动能．文中讨论了振动激发的机理．

IR, diode laser probing technique has been used to detect the vibrational energy transfer of NH3(ν2) excited by the relaxation of high energy NO2 molecule. NO2 was pumped by YAG 532nm laser. The time resolved absorption spectra of NH3(ν2) ro-vibronic levels were detected by diode laser. When the pressure ratios of NO2:NH3 were 1:5, 1:1, 2:1 and 5:1, the excited rate constants of NH3(0100;7,k) are 9.28×10-1,6.42×10-1 t 5.05×10-1，3.65×10-1 ms-1·Pa-1 respectively. The amount of energy transferred from excited NO2 to the ν2 mode of NH3 was found to be 6% of the original excitation energy. Most of the excitation energy was transferred to rotational and translational energy of NH3. The mechanism of vibrational excitation was discussed.