碰撞振动能量转移:Li_2[A^1∑_u^+(v′=7)]+He→Li_2[A^1∑_u^+(v''=6,8)]+He

Collision-induced Vibrational Energy Transfer:Li_2[A^1∑_u^+(v′=7)]+He→Li_2[A^1∑_u^+(v''=6,8)]+He

利用激光诱导荧光方法研究了Li_2[A^1∑_u^+(v′=7)]与He的碰撞能量转移.脉冲激光激发Li_2基态至Li_2[A^1∑_u^+(v″=7)]态,池温保持在623K,He气压在1Torr至10Torr之间变化,在He气体不同压强下,测量了转移荧光和直接荧光的时间积分荧光强度比.结合能级的速率方程分析,得到了v′=7的单量子驰豫转移速率系数和总去布居速率系数如下:k_(67)=(1.20±0.48)×10^(-8)cm^3·s^(-1);k_6=(0.88±0.26)×10^(-8)cm^3·s^(-1);k_(78)=(2.52±0.63)×10^(-9)cm^3·s^(-1);k_8=(1.00±0.30)×10^(-8)cm^3·s^(-1).

Collisional energy transfer Li2[A^1∑u^＋（v′= 7）]with He has been studied by laser induced fluorescence.Li2 molecules were irradiated in a cell with pulses of radiation from a dye laser,populating Li2[A^1∑u^＋（v′=7）]by photon absorption.During the experiment,the cell temperature was kept constant at 623 K.The He pressure was varied between ITorr and lOTorr,Under different pressures of He gas,we have measured the time-integrated fluorescence intensity ratio of transfer fluorescence and direct fluorescence of Li2[A^1∑u^＋（v＇= 7）].Using the method of molecular fluorescence spectrometry with level rate equation model analysis,single quantum relaxation transfer rate coefficient and total depopulation rate coefficients of Li2 of v＇=7are as follows：k67=（1.20 ± 0.48）×10^-8 cm^3 ·s^-1;k6=（0.88 ± 0.26）×10^-8 cm^3·s-1;k78=（2.52 ± 0.63）×10^-9cm^3 ·s^-1;k_8=（1.00 ±0.30）×10^-8cm^3·s^-1.