首页 | 本学科首页   官方微博 | 高级检索  
     检索      

Cs_2(B~1Π_u)态与基态Cs原子间的碰撞激发转移
引用本文:王敏,周冬冬,王雪燕,穆尼赛·努,戴康,王倩,沈异凡.Cs_2(B~1Π_u)态与基态Cs原子间的碰撞激发转移[J].光谱学与光谱分析,2009,29(11):2889-2892.
作者姓名:王敏  周冬冬  王雪燕  穆尼赛·努  戴康  王倩  沈异凡
作者单位:新疆大学物理科学与技术学院,新疆,乌鲁木齐,830046
基金项目:国家自然科学基金项目 
摘    要:在Cs2密度约为2×1013 cm-3的纯Cs样品池中,脉冲激光激发Cs2(X1 Σg+)至B 1Πu态,利用原子和分子荧光光谱方法研究了Cs2(B 1Πu)+Cs(6S)的碰撞激发转移过程.用736 nm激发Cs2到B 1Πu(v<10),这时预解离不发生.由B 1Πu→X1 Σg+时间分辨跃迁信号得到B 1Πu态的辐射寿命为(35±7)ns,B1Πu态与Cs原子碰撞转移总截面为(4.0±0.5)×10-14 cm2.用705 nm激发至B 1Πu(v>30)态,这时发生预解离,在不同的Cs密度下,测量了I(D1),I(D2)和分子带的时间积分荧光的相对强度,得到了预解离率为(4.3±1.7)×105 s-1(对预解离到6P3/2)和(4.7±1.9)×106 s-1(对预解离至6P1/2);碰撞转移截面为(0.45±0.18)×10-14 cm2(对转移到6 P1/2)和(4.3±1.7)×10-14 cm2(对转移到6P3/2).结果表明,如果B 1Πu(v)是束缚的,6P原子由碰撞转移产生;如果B 1Πu(v)是预解离的,则6P原子由预解离和碰撞转移产生.

关 键 词:碰撞能量转移  预解离  荧光  截面
收稿时间:2008/11/6

Collisional Excitation Transfer between Cs2(B 1Πu)and Cs(6S)
Institution:WANG Min,ZHOU Dong-dong,WANG Xue-yan,MU Nisai·NU,DAI Kang,WANG Qian,SHEN Yi-fan College of Physics Science and Engineering,Xinjiang University,Urumqi 830046,China
Abstract:With a Cs density of ~1015 cm-3 and typically ~2% Cs2, cesium vapor was irradiated in a glass fluorescence cell with pulses of radiation from a YAG-laser- pumped OPO laser, populating Cs2(B 1Πu) state by one-photon absorption. Predissocia- tion of the B 1Πu state and energy transfer in Cs2(B 1Πu)+Cs(6S) collisions were studied using methods of atomic and molecular fluorescence. The B 1Πu(v<10)state does not predissociate in Cs vapor excited at λ=736 nm. The decay signal of the time-resolved fluorescence from the B 1Πu→X 1Σ+g transition was monitored. According to the Stern-Volmer equation, a plot of reciprocal of effective lifetimes of the Cs2(B 1Πu) state quenched by Cs(6S) atoms against its densities yielded a slope that indicated the total cross section for deactivation and an intercept(at which the Cs pressure is zero) that provided the information on the radiative lifetime of the state. The radiative lifetime is (35±7)ns for the B 1Πu state. The total cross section for deactivation of excited Cs2 [B 1Πu(v<10)]molecules by means of collisions with Cs atoms is(4.0±0.5)×10-14 cm2. The B 1Πu(v>30) state predissociates in Cs vapor excited at λ=705 nm. At the different Cs densities, the relative time-integrated intensities of the resulting Cs emission lines, I(6P1/2→6S1/2)[I(D1)] and I(6P3/2→6S1/2)[I(D2)], and Cs2 (B 1Πu) band-pass(725→735 nm)I[Cs2(B 1Πu)] were measured. By combining Cs 6P fine-structure mixing and quenching induced by collisions with ground Cs atoms, the authors obtained absolute values for predissociation and collisional transfer cross sections. The predissociation rates are (4.3±1.7)×106 s-1(for predissociating to 6P3/2) and (4.7±1.9)×106 s-1 (for predissociating to 6P1/2), respectively. The collisional transfer cross sections are (0.45±0.18)×10-14 cm2(for transfering to 6P1/2)and(4.3±1.7)×10-14 cm2 (for transfering to 6P3/2). These experimental results show that if Cs2 excited state is predissociation state, it can produce Cs(6P) atoms by predissociation and collisional transfer; if Cs2 excited state is bound, it can produce produce Cs(6P) atoms by collisional transfer.
Keywords:Cs2
本文献已被 CNKI 万方数据 等数据库收录!
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号