碰撞诱导振动能量转移:Cs_2[B^1∏_u(u′=5)]+N_2→Cs_2[B^1∏_u(v′=4,6)]+N_2  

Collision-induced vibrational energy transfer: Cs_2[B^1 Ⅱ_u(v′=5)]+N_2→Cs_2[B^1 Ⅱ_u(v′=4,6)]+N_2

作　　者：穆尼赛.努 普拉提.艾 周冬冬[1] 王大贵[1] 王雪燕[1] 沈异凡[1] 

机构地区：[1]新疆大学物理科学与技术学院,乌鲁木齐830046

出　　处：《原子与分子物理学报》2010年第1期97-101,共5页Journal of Atomic and Molecular Physics

基　　金：国家自然科学基金(10664003)

摘　　要：利用激光诱导荧光方法研究了Cs_2B^1∏_u[(v′=5)]与N_2的碰撞能量转移.脉冲激光激发Cs_2基态至B^1∏_u[(v′=5)]态,池温保持在410K,N_2气压在1.5×10~2Pa～2.5×10~3Pa之间变化.荧光中含有直接荧光和碰撞转移荧光成分,记录直接荧光B^1∏_u(v′=5)→X^1∑_8^+(v″=0)的时间分辨强度.从荧光强度的对数值给出的直线斜率得到B^1∏_u(v′=5)→X^1∑_8^+(v″=0)的有效寿命,由Stern—Volmer方程,得到B^1∏_u(v′=5)→X^1∑_8^+(v″=0)的辐射寿命为(45±9)ns.B^1∏_u(v′=5)态与N_2碰撞的猝灭总截面为(9.8±1.5)×10^(-15)cm^2.用类似的方法得到B^1∏_u(v′=4,6)能级的辐射寿命.在不同的N_2气压下,测量B^1∏_u(v′=5,4,6)→X^1∑_8^+(v″=0)的时间积分荧光强度,首次得到v′=5→v′=4及v′=5→v′=6的碰撞转移截面分别为(3.9±0.8)×10^(-15)cm^2和(4.1±0.8)×10^(-15)cm^2.Collisional energy transferCs2[B1Пu（v′=5）]with N2 has been studied by laser induced fluorescence. Cs2 molecules were irradiated in a cell with pulses of radiation from a OPO laser, populating Cs2[B1Пu（v′=5）] by photon absorption. During the experiments, the cell temperature was kept constant at 410K. The N2 pressure was varied between 1.5× 10^2 Pa and 2.5 × 10^3 Pa. The resulting fluorescence included the direct component emitted in the decay of the optically excited state and the sensitized components arising from collisionally populated states. The decay signal of time-resolved fluorescence from B1Пu（v′=5）→X1∑G^＋（v″=0） transition was monitored. The semilog plot of the time-resolved fluorescence was shown. The slope yielded the effective lifetime. Based on the Stern- Volmer equation, radiative lifetime （45± 9ns）is obtained. The total cross section for deactivation of B1H. （v＇= 5） state by means of collisions with N2 is （9.8±1.5））〈 10^-15 cm2. The radiative lifetimes of BlIIu（vt=4,6） states can also be determined through analogous procedure. The time - integrated intensities of B1Пu（v′=5）→X1∑G^＋（v″=0） transitions at different N2 pressure were measured. The cross sections （3.9±0.8）×10^-15 cm2（for v′=5→v′=4） and （4. 1±0.8） × 10 knowledge, the cross-sections for these processes are Key words： collisional energy transfer, time-resolved tion, Cs-N2 -15 cm2（for v′=5→v′=6） are obtained. To our knowledge, the cross-sections for these processes are reported here for first time.

关 键 词：碰撞能量转移 时间分辨荧光强度 时间积分光强 截面 Cs—N2 

分 类 号：O562.5[理学—原子与分子物理] O562.4[理学—物理]