Laser-induced Alignment and Coulomb Explosion of CO2

Dynamic processes of CO2 are experimentally studied in intense femtosecond laser fields with laser intensity varying from 1×10^13 W/cm^2 to 6×10^14 W/cm^2. When the laser intensity is below the ionization threshold, a coherent rotational wave-packet is formed for CO2 at room temperature through nonadiabatic rotational excitation. The evolution of the wave-packet leads to transient alignment. The field-free alignment revives periodically after the laser pulse is over. The revival structure can be modified by a second laser pulse for the rotational wave-packet through precisely adjusting the time delays between the two laser pulses. When the laser intensity excesses the ionization threshold, ionization and Coulomb explosion occur. The atomic ions C^m＋ （re=1-3） and On＋ （n=1-3） observed in the experiment exhibit highly anisotropic angular distributions relative to the laser polarization. Using two linearly polarized laser pulses with crossed polarization, we conclude that the anisotropic angular distribution results from dynamic alignment, in which the rising edge of the laser pulse aligns the neutral CO2 along the laser polarization direction prior to ionization.     

关于激光诱导裂析谱专题的欧洲-地中海会议2007 (Ⅰ)

本届会议于2007年9月10日至13日在法国巴黎市召开, 由会议筹备组EMSLIBS主办, 会议共分9组. 短时讲座5个: (1) 准确度与校正的概念; (2) 如何改进激光诱导裂析谱方法的校正; (3) 激光参数在激光物质相互作用中扮演的角色; (4) 激光诱导的等离子体的鉴定; (5) 等离子体探针技术.     

铀原子跃迁的自发发射分支比、相对振子强度、跃迁几率和能级寿命的测量与计算

本文首次提出用激光诱导敏化荧光光谱法测量铀原子5f³6d7s7p-⁷M₇,5f6d7s7p-^?L₆,5f³7p-⁵K₆,5f²6d²7s²-⁵L₇,5f₄d7s-⁷L₆,(17070cm^-1)-⁵L₆,5f²6d²7s²-⁵K₆,5f³6d7s7p-⁷L₅,5f³6d7s7p-⁷K₅,5f²6d²7s2-⁵I₅ 10个能级向基态跃迁的自发发射分支比;采用空心阴极发射光谱法测量了它们的相对振子强度;测量并计算了这些能级的寿命及其基态跃迁的自发发射跃迁几率,获得了较高的测量准确度和分辨率。