Zhu Yong-Le, Wang Shu-Ying, Liu Jing, Zhong Chong-Yu, Yolwas A, Dai Kang, Shen Yi-Fan
Guang Pu Xue Yu Guang Pu Fen Xi. 2014 Apr;34(4):884-7.
The radiative lifetimes and rate coefficients for deactivation of high lying 6(1)sigma+ state of NaK by collisions with H2 were studied. An OPO laser was set to a particular 2(1)sigma+ <-- 1(1)sigma+ transition. Another single mode Ti sapphire laser was then used to excite molecule from 2(1)sigma+ level to the 6(1)sigma+ state. The predissociation was monitored by the atomic potassium emission at the 3D --> 4P (1.7 microm) or the S --> 4P (1.24 microm), while bound state radiative processes were monitored by total fluorescence from the upper state to the various levels, all studied as a function of H2 density. The values for predissociation, collisional dissociation and collisional depopulation rate coefficients were obtained. The decay signal of the time resolved fluorescence from the 6(1)sigma+ --> 2(1)sigma+, 6(1)sigma+ -->1(1)sigma+ or 2(1)sigma+ --> 1(1)sigma+ transition was monitored. Based on the Stern-Volmer equation, the radiative lifetimes were monitored for 6(1)sigma+ --> 2(1)sigma+ and 2(1)sigma+ --> 1(1)sigma+ transition. The rate coefficients for deactivation of collisions with H2 were monitored for 6(1)sigma+ --> 2(1)sigma+, 6(1)sigma+ --> 1(1)sigma+ and 2(1)sigma+ -->1(1)sigma+. When the density of H2 was 10(19) cm(-3), the total collisional transfer energy (15 426 cm(-1)) and radiative energy (10 215 cm(-1)) were obtained. The relative fraction ((f(v)), (f(R)), (f(T)) of average energy disposal was derived as (0.58, 0.03, 0.39); (f(v)), (f(R)), (f(T)) represent separately the relative fraction of average energy disposal among vibration, rotation and translation. The major vibrational and translational energy release supports the assumption that the 6(1)sigma(+) -H2 collision occurs primarily in a collisional energy transfer mechanism. In this experiment, alkali molecules relative energy population ratio was determined through using the time integrated intensity, so we can get the total transfer energy. That the NaK (6(1)sigma+) energy transfers to the H2 vibrational, rotational and translational energy was quantitatively given for the first time, which illustrates the collisional mechanism.
研究了与H₂碰撞使NaK的高激发态6(¹)σ⁺失活的辐射寿命和速率系数。将一台光学参量振荡器（OPO）激光器设置为特定的2(¹)σ⁺ ← 1(¹)σ⁺跃迁。然后使用另一台单模钛宝石激光器将分子从2(¹)σ⁺能级激发到6(¹)σ⁺态。通过3D → 4P（1.7微米）或S → 4P（1.24微米）处的原子钾发射监测预解离，而通过从高激发态到各个能级的总荧光监测束缚态辐射过程，所有这些都作为H₂密度的函数进行研究。获得了预解离、碰撞解离和碰撞去布居速率系数的值。监测了6(¹)σ⁺ → 2(¹)σ⁺、6(¹)σ⁺ → 1(¹)σ⁺或2(¹)σ⁺ → 1(¹)σ⁺跃迁的时间分辨荧光的衰减信号。基于斯特恩 - 沃尔默方程，监测了6(¹)σ⁺ → 2(¹)σ⁺和2(¹)σ⁺ → 1(¹)σ⁺跃迁的辐射寿命。监测了6(¹)σ⁺ → 2(¹)σ⁺、6(¹)σ⁺ → 1(¹)σ⁺和2(¹)σ⁺ → 1(¹)σ⁺与H₂碰撞失活的速率系数。当H₂密度为10¹⁹ cm⁻³时，获得了总碰撞转移能量（15426 cm⁻¹）和辐射能量（10215 cm⁻¹）。平均能量分配的相对分数（(f(v))、(f(R))、(f(T))）推导为(0.58, 0.03, 0.39)；(f(v))、(f(R))、(f(T))分别表示振动、转动和平动之间平均能量分配的相对分数。主要的振动和平动能释放支持了6(¹)σ⁺ - H₂碰撞主要通过碰撞能量转移机制发生的假设。在本实验中，通过使用时间积分强度确定了碱分子相对能量布居比，从而可以得到总转移能量。首次定量给出了NaK (6(¹)σ⁺)能量转移到H₂的振动、转动和平动能量的情况，这阐明了碰撞机制。
