CAJ | 학술논문

利用受激发射泵浦激发Na2分子，使Na2[X1∑g＋（ν″＝33，J″＝11）]得到布居，研究了高振动激发态Na*2与Ar和N2的碰撞弛豫过程。由激光诱导荧光得到Na2（ν≤33）各振动能级的时间分辨布居分布，从而得到Boltzmann振动温度和转动温度随时间的变化。对于Na*2与Ar碰撞，在泵浦－探测延迟时间tD＝8μs前，振动温度Tvib减小很慢；在8－12μs间， Tvib迅速下降并达到平衡。而转动温度Trot和平移温度Ttran在Tvib迅速下降时才开始缓慢增加。对于Na*2与N2碰撞， Tvib存在三个变化阶段，先是迅速下降，然后下降减缓，最后减小很慢并达到平衡。而在整个过程中， Trot和Ttran一直是很缓慢地增加。实验数据说明了弛豫过程是分阶段进行的，单一速率系数不能正确解释复杂的弛豫过程，并会丢失平衡过程中的关键特点。
이용수격발사빙포격발Na2분자，사Na2[X1∑g＋（ν″＝33，J″＝11）]득도포거，연구료고진동격발태Na*2여Ar화N2적팽당이예과정。유격광유도형광득도Na2（ν≤33）각진동능급적시간분변포거분포，종이득도Boltzmann진동온도화전동온도수시간적변화。대우Na*2여Ar팽당，재빙포－탐측연지시간tD＝8μs전，진동온도Tvib감소흔만；재8－12μs간， Tvib신속하강병체도평형。이전동온도Trot화평이온도Ttran재Tvib신속하강시재개시완만증가。대우Na*2여N2팽당， Tvib존재삼개변화계단，선시신속하강，연후하강감완，최후감소흔만병체도평형。이재정개과정중， Trot화Ttran일직시흔완만지증가。실험수거설명료이예과정시분계단진행적，단일속솔계수불능정학해석복잡적이예과정，병회주실평형과정중적관건특점。
Stimulated emission pumping was used to excite Na2 [ X1∑g+(ν″=33,J″=11) ] via A-X transition. Laser induced fluorescence was used to follow the collision dynamics.Relaxation processes induced by collisions with Ar and N2 were investigated.For Na*2 in a bath of Ar gas, the equilibration takes place via distinct phases, main features of which are a very slow initial vibrational relaxation up to tD =8 μs,that then speeds up before reaching a quasiequilibrium soon after tD=12 μs.Trot and Ttran begin to increase at the onset of faster decline in Tvib.For Na*2 in a bath of N2 gas, the variation of Tvib indicates the existence of three principal change regions in this equilibration process.The initial phase consists of very rapid fall in Tvib.This phase of major vibrational en-ergy exchange is followed by one of slightly rapid Tvib decline that precedes a third phase of much slower change. The data demonstrate that single rate coefficient measurements are unlikely to capture the complex nature of processes that generally are multistage with different relaxation rates characterizing each different stage.The re-sults suggest that single quantum state population loss rate constants may miss key features of the overall equili-bration process.