共查询到20条相似文献,搜索用时 93 毫秒
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脉冲激光激发NaK 2~1Σ~+←1~1Σ~+跃迁,单模Ti宝石激光器激发2~1Σ~+至高位态6~1Σ~+,研究了6~1Σ~+与H_2碰撞中的碰撞转移。3D→4P(1.7μm)和5S→4P(1.24μm)荧光发射说明了预解离和碰撞解离的产生。在不同的H_2密度下,通过以上能级的荧光测量得到了预解离率,碰撞解离及碰撞转移速率系数Γ_(3D)~P=(5.3±2.5)×10~8 s~(-1),Γ_(5S)~P=(3.1±1.5)×10~8 s~(-1),k_(3D)=(3.7±1.7)×10~(-11)cm~3·s~(-1),k_(5S)=(2.9±1.4)×10~(-11)cm~3·s~(-1),k_(4P→4S)=(1.1±0.5)×10~(-11)cm~3·s~(-1),k_(3D→4P)=(6.5±3.1)×10~(-12)cm~3·s~(-1),k_(5S→4P)=(4.1±1.9)×10~(-12)cm~3·s~(-1)在不同H_2密度下,记录时间分辨荧光,由Stern-Volmer公式得到6~1Σ~+→2~1Σ~+,2~1Σ~+→1~1Σ~+的自发辐射寿命分别为(28±10)ns和(15±4)ns。6~1Σ~+→2~1Σ~+6~1Σ~+→1~1Σ~+及2~1Σ~+→1~1Σ~+分子态间与H_2的碰撞转移速率系数分别为(1.8±0.6)×10~(-11)cm~3·s~(-1),(1.6±0.5)×10~(-10)cm~3·s~(-1)和(6.3±1.9)×10~(-11)cm~3·s~(-1)。转移到H_2的振动、转动和平动能各占总转移能的0.58,0.03和0.39。主要能量转移至振动和平动能,支持6~1Σ~+-H_2间的共线型碰撞机制。 相似文献
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本文用文献[1]的方法从介子交换观点讨论了三超子与核子的相互作用,利用单玻色子交换(OBEP)和双玻色子交换(TBEP)两种机制,在低能近似下,得到一个Σ-N相互作用势.计算表明只有同位旋I=3/2,自旋S=0的Σ-N系统有可能存在束缚态. 相似文献
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Theoretical study of spin-forbidden cooling transitions of indium hydride using ab initio methods 下载免费PDF全文
The feasibility of spin-forbidden cooling of the In H molecule is investigated based on ab initio quantum chemistry calculations. The potential energy curves for the X~1Σ_(0~+)~+, a~3Π_~(0~-), a~3Π_(0~+), a~3Π_1, a~3Π_2, A~1Π_1, 1~3Σ_(0~-)~+, and 1~3Σ_1~+states of In H are obtained based on multi-reference configuration interaction plus the Davidson corrections method. The calculated spectroscopic constants are in good agreement with the available experimental data. In addition, the influences of the active space and spin–orbit coupling effects on the potential energy curves and spectroscopic constants are also studied. For Re of a~3Π_(0~-), a~3Π_(0~+), a~3Π_1, and a~3Π_2 states, the error from large active space is small. The potential energy curve of the A~1Π_1state is not smooth for small active space. The spin–orbit coupling effects have great influences on the potential well depth and equilibrium internuclear distance of the A~1Π state. The Franck–Condon factors and radiative lifetimes are obtained on the basis of the transition dipole moments of the a~3Π_(0~+) → X~1Σ_(0~+)~+, a~3Π_1 → X~1Σ_(0~+)~+, and A~1Π_1 → X~1Σ_(0~+)~+ transitions. Our calculation indicates that the a~3Π_1( ν'= 0) → X~1Σ_(0~+)~+(ν = 0) transition provides a highly diagonally distributed Franck–Condon factor and a short radiative lifetime for the a3Π1 state, which can ensure rapid and efficient laser cooling of In H.The proposed laser drives a~3Π_1 → X~1Σ_(0~+)~+ transitions by using three wavelengths. 相似文献
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《量子光学学报》2021,(1)
本文3~3Σ_1~+以为中间激发态,通过扫描光缔合光的频率得到了3~3Σ_1~+的不同振动态光谱。研究发现利用短程光缔合制备的超冷基态~(85)Rb~(133)Cs分子产率在3~3Σ_1~+(v=3)处较其他振动态更大,3~3Σ_1~+(v=3)转动常数较邻近的振动态有明显变化且与2~3Π_(0-)(v=14)的能量接近,这些特征显示了这两个振动态的共振耦合特性。优化光缔合光的功率和光电离光的能量后,我们得到X~1Σ~+(v=0)最低振动态超冷~(85)Rb~(133)Cs分子的产率为1.5×10~4/s。在考虑了分子波函数的宇称和跃迁选择定则后,我们发现3~3Σ_1~+(v=3,J=1)存在单步自发辐射制备超冷基态~(85)Rb~(133)Cs分子的通道,采用该通道可实现原子-分子相干转移直接制备超冷基态分子。 相似文献
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用光学 光学双共振激光光谱研究了 7Li2 A1Σ+ u 态的Autler Townes (A T)分裂 .一个强的耦合场 (泵浦激光 )激发 7Li2 A1Σ+ u v′ ,J′←X1Σ+ g v″,J″跃迁 ,诱发A1Σ+ u v′ ,J′能级和X1Σ+ g v″ ,J″能级的A T分裂 .另一个探测激光从A1Σ+ u v′ ,J′能级进一步激发到 4 1Σ+ g 态 .扫描探测激光 ,监测 4 1Σ+ g 态碰撞诱导紫色荧光 ,从而探测A1Σ+ u v′,J′能级的A T分裂 .当耦合场频率偏离共振时 ,激发光谱线出现双重分裂 .在该实验条件下 ,分裂大小和泵浦激光频率偏离共振频率的失谐量成正比 .研究了A T分裂的两条线的相对强度与泵浦、探测光的强度及缓冲气体压力的关系 . 相似文献
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利用考虑Davidson修正的内收缩多参考组态相互作用(icMRCI+Q)方法结合相关一致基组aug-ccpV6Z计算了AlH~+离子前两个离解极限对应的5个Λ-S态和10个?态的势能曲线.为了提高势能曲线的可靠性和精确性,计算中考虑了自旋轨道耦合效应、芯电子价电子相关和标量相对论修正以及将势能外推至完全基组极限.基于得到的势能曲线,获得了束缚和准束缚的4个Λ-S态和8个?态的光谱常数和振动能级,与已有的实验结果符合.计算了2(1/2)→X~2Σ_(1/2)~+和A~2Π_(3/2)→X~2Σ_(1/2)~+跃迁的跃迁偶极距.利用计算的精确的势能曲线和跃迁偶极矩,获得了2(1/2)~(第一势阱)(υ′=0, 1)→X~2Σ_(1/2)~+(υ′′)和A~2Π_(3/2)(υ′=0, 1)→X~2Σ_(1/2)~+(υ′′)跃迁的高度对角化分布的Franck-Condon因子(f_(00)和f_(11))和大的振动分支比;预测了2(1/2)~(第一势阱)(υ′=0, 1)和A~2Π_(3/2)(υ′=0, 1)态短的自发辐射寿命和窄的辐射宽度,这适合于AlH~+离子的快速激光致冷.所需的3束激光冷却波长都在紫外区域.这些结果表明了激光冷却AlH~+离子的可行性.此外,评估了自旋轨道耦合效应对光谱常数、振动能级和激光冷却AlH~+离子的影响. 相似文献
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根据Su_3对称的八度法模型,已知的八种重子(N,Ξ,Σ,Λ)与八种赝标量介子(K,K,π,η)分别构成了简并的超多重态:8_1与8_0(脚标表示重子数)。因此,重子共振态应属于它们的乘积表示: 相似文献
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Recently, there have been great interest and advancement in the field of laser cooling and magneto-optical trapping of molecules. The rich internal structure of molecules naturally lends themselves to extensive and exciting applications. In this paper, the radical~(138)Ba~(19) F, as a promising candidate for laser cooling and magneto-optical trapping, is discussed in detail.The highly diagonal Franck–Condon factors between the X~2Σ~+_(1/2)and A~2Π_(1/2) states are first confirmed with three different methods. Afterwards, with the effective Hamiltonian approach and irreducible tensor theory, the hyperfine structure of the X~2Σ~+_(1/2)state is calculated accurately. A scheme for laser cooling is given clearly. Besides, the Zeeman effects of the upper(A~2Π_(1/2)) and lower(X~2Σ~+_(1/2)) levels are also studied, and their respective g factors are obtained under a weak magnetic field.Its large g factor of the upper state A~2Π_(1/2) is advantageous for magneto-optical trapping. Finally, by studying Stark effect of Ba F in the X~2Σ~+_(1/2), we investigate the dependence of the internal effective electric field on the applied electric field. It is suggested that such a laser-cooled Ba F is also a promising candidate for precision measurement of electron electric dipole moment. 相似文献
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我们得到了CO经过共振态A~1∏态和e~3∑~-态的转动分辨的紫外双光子共振四光子电离光谱,并测量了它们的双光子吸收截面,σ_(Xe)~(2)、σ_(A1)~(2)=1.4×10~(99)cm~8sec~(-1),σ_(A1)~(2)=2.6×10-~(50)cm~4see_(-1).用双色共振增强的方法明确地归属了受到扰动的CO A←X双光子吸收(0.0)带. 相似文献
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利用高分辨快电子能量损失谱仪, 在入射能量2 500 eV,散射角0°~7°, 能量分辨50 meV条件下, 测量了CO在7~21 eV能量区间的能谱,获得了更宽动量转移范围内电子态A1Π、B1Σ+、C1Σ+与E1Π的振动强度分布的动量转移依赖关系,其中A1Π振动强度的分布与动量转移大小无关, 而其他三个跃迁振动强度的分布依赖于动量转移. 相似文献
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以前我们曾用双费米子跃迁模型讨论了超子的非轻子衰变,得到比较满意的结果,但假定了Λ→p+π~-和Σ~+→p+π~0的上下不对称参数α_Λ和α_0具有相同的符号。现在的一些实验值指出α_Λ≈-α_0。如果这些实验结果正确,则必须放弃或者修改我们的理论。本文在以前工作的基础上,从SU_3羣理论出发,加入K介子中间态的贡献,得到比较满意的结果。 相似文献
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Based on group theory and atomic and molecular reaction statics, this paper derives the possible electronic states of C^{2+}_2, C^{2-}_2 and C^{3+}_2, and their reasonable dissociation limits and determines their ground electronic states C^{2+}_2(X^3Π_u), C^{2-}_2(X^1Σ^+_g) and C^{3+}_2(X^4Σ^-_u) using quantum mechanical calculations at the level of QCISD/6-311G^*. All the potential energy curves of their ground states have both a minimum and a maximum, which are the so-called "energy trapped" molecules. This sort of potential maximum is chiefly due to Coulomb repulsion. We propose the perturbation effect of ionic charges, which is used to explain why the orbital degeneracy of diatomic ions may be removed. The characteristics of potential curves for diatomic ions are briefly described. 相似文献