等电荷态离子与He原子碰撞中的转移电离过程研究

采用位置灵敏探测和飞行时间技术测量了等电荷态离子C^q 、N^q 、O^q 、Ne^q (q=4，5，6，7)与He原子碰撞中，转移电离截面与单电子俘获截面的比值Ro研究了相同q入射的情况下，R与入射离子核电荷数Z的依赖关系。在统计蒸发模型的基础上对实验结果进行了解释。     

氦原子(e,2e)反应中库仑波描述入射电子的理论研究

在前期工作的基础上,当初通道使用具有有效电荷库仑波时,完成了电子入射离化氦原子三重微分截面的理论推导.计算表明初通道库仑场对较低入射能量情况下,(e,2e)过程的三重微分截面有较大影响.     

L-Shell X-Ray Yields and Production Cross Sections of Zr and Mo Bombarded by Slow Highly Charged Ar16+ Ions

The L-shell x-ray yields of Zr and Mo bombarded by slow Ar16＋ ions are measured. The energy of the Ar^16＋ ions ranges from about 150 keV to 350 keV. The L-shell x-ray production cross sections of Zr and Mo are extracted from these yields data. The explanation of these experimental results is in the framework of the adiabatic direct- ionization and the binding energy modified BEA approximation. We consider, in the slow asymmetric collisions such as Ar and Mo/Zr, the transient united atoms （UA） are formed during the ion-surface interaction and the direct-ionization is the main mechanism for the inner-shell vacancy production. Generally, the theoretical results are in good agreement with the experimental data.     

中高能电子散射全截面测量装置的设计

介绍了中高能电子散射全截面绝对测量装置的设计,采用直线透射技术.因采用了恒温控制作用室,以便较准确测量反应室的绝对气压值;同时采用静电型圆柱能量分析器,并用计数率测量模式代替通常的束流强度测量模式,从而可以大幅度减小接收立体角,抑制零度角的弹性散射贡献.通过以上几项措施,可以有效地提高测量的精度,从而可以对一些有意义的分子的中、高能电子散射全截面进行绝对测量.     

Guided transmission of oxygen ions through Al2O3 nanocapillaries

The transmissions of oxygen ions through Al2O3 nanocapillaries each 50 nm in diameter and 10 μm in length at a series of different tilt angles are measured,where the ions with energies ranging from 10 to 60 keV and charge states from 1 up to 6 are involved.The angular distribution and the transmission yields of transported ions are investigated.Our results indicate both the existence of a guiding effect when ions pass through the capillary and a significant dependence of the ion transmission on the energy and the charge state of the ions.The guiding effects are observed to be enhanced at lower projectile energies and higher charge states.Meanwhile,the results also exhibit that the transmission yields increase as the tilt angle decreases at a given energy and charge state.     

Angular momentum distribution in strong-field frustrated tunneling ionization

Using the classical-trajectory Monte Carlo model, we have theoretically studied the angular momentum distribution of frustrated tunneling ionization(FTI) of atoms in strong laser fields. Our results show that the angular momentum distribution of the FTI events exhibits a double-hump structure. With this classical model, we back traced the tunneling coordinates, i.e., the tunneling time and initial transverse momentum at tunneling ionization. It is shown that for the events tunneling ionized at the rising edge of the electric field,the final angular momentum exhibits a strong dependence on the initial transverse momentum at tunneling.While for the events ionized at the falling edge, there is a relatively harder recollision between the returning electron and the parent ion, leading to the angular momentum losing the correlation with the initial transverse momentum. Our study suggests that the angular momentum of the FTI events could be manipulated by controlling the initial coordinates of the tunneling ionization.     

高亮度大功率半导体激光器光纤耦合模块

应用ZEMAX软件设计出高亮度大功率光纤耦合模块。采用16支输出功率12 W的单偏振态单边发射半导体激光器,耦合进芯径100 μm、数值孔径0.22的光纤中。模块输出功率达到189.4 W,耦合效率达到98.6%,亮度达到94.66 MW/cm²-str。通过SolidWorks软件优化得到新热沉结构,应用ANSYS软件进行热分析,结果表明新热沉结构最高温度为42.4℃,相比优化前温度降低1℃以上,得到良好散热结构模型。     

烧结空洞对半导体激光器热分布的影响

在半导体激光器芯片与热沉的焊接过程中不可避免地会在焊料层产生一些空洞,而空洞会在铟的电迁移以及电热迁移作用下慢慢变大,使芯片局部温度迅速上升,进而影响半导体激光器的性能。针对10 W的808 nm单管焊装半导体激光器建立三维有限元模型,分别模拟计算了空洞面积、空洞厚度和空洞位置与结温的关系。芯片出光面边缘的有源区区域形成的空洞对芯片的结温影响更为显著,最后得到空洞面积与器件结温的关系,并表明对空洞率控制的重要性。     

Na离子和Cl离子引起He原子直接多重电离过程的研究

利用2～8 MeV的Naq+、Clq+(q=2,3,4,5)轰击氦原子,对碰撞的直接多重电离过程进行研究.实验采用反冲离子-散射离子飞行时间符合技术,通过反冲离子飞行时间谱区分不同价态反冲离子;利用静电偏转和位置灵敏探测技术区分不同电荷态散射离子;结合CAMAC-PC多参数获取系统得到一定价态散射离子所对应的反冲离子电荷态分布谱;经分析该谱得到直接多重电离截面与直接单电离截面之比R21.讨论了R21随入射离子速度和电荷态的变化关系.     

高电荷态Ar^q＋与Ne碰撞中入射离子电荷交换截面的研究

报道Ar^q Ne(q=8，9，11，12)碰撞体系中多电子转移过程，得到了多组实验测量电荷交换截面数据，讨论入射离子电荷交换截面、反冲离子产生截面与入射离子电荷态、能量以及散射离子电荷态的关系，并且将实验结果与Ar^q Ar碰撞体系进行对比研究。在修正分子库仑过垒模型的基础上，对实验现象做了合理的解释。