共查询到19条相似文献,搜索用时 62 毫秒
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利用电子迥旋共振(ECR)多电荷离子源产生的高电荷态离子束和LHT—30VUV真空紫外单色仪,研究了N~6+、O~5+、Ne~4+与He碰撞激发过程,观察到单电子俘获、双电子俘获和入射离子直接激发三种激发过程。 We have investigated the excitation processes in collisions between N~(6+), O~(5+), Ne~(4+) andHe by using the ECR ionic source and the LHT-30 VUV Monochromator. The emission spectra showthat there are three channels of excitation in the N~(6+)+He collision system: (1) Single electroncapture into excited states; (2) Double electron capture into excited states; (3) Direct excitation ofincident ions. 相似文献
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研究了平行玻璃板对高流强(约80 nA)105 keV Ar7+离子的导向效应, 利用一维位置灵敏探测器测量了不同倾斜角下出射离子的强度及角分布。 实验结果表明, 平行玻璃板对Ar7+离子有导向作用。 与离子在微孔膜中的导向效应不同, 从平行玻璃板出射的Ar离子角分布的FWHM随着倾斜角的改变而改变, 并且出射离子角分布最大值处对应的观察角不等于倾斜角。 The transmission of 105 keV Ar7+ ions with high incident current (about 80 nA) through the gap formed by a paired parallel glass plates was investigated. The intensity and angular distribution of the transmitted ions for various tilt angles were measured using a one dimensional position sensitive detector. The results indicate the existence of a guiding effect when Ar7+ ions pass through the gap, but it is different from that for ions passing through nonacapillaries. We found a measurable dependence of the full width at half maximum (FWHM) of the transmitted ions as a function of the tilt angle. In addition, when the gap was tilted with respect to the direction of the incident beam, the observation angle related to the center of the transmitted ions profile was not equal to the tilt angle. 相似文献
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论述了高电荷态离子与表面相互作用的过程 ,说明了发射电子、发射光子、负离子、中性粒子、正离子的散射和发射的物理机理以及应用前景 .介绍了在兰州重离子国家实验室ECR源建立高电荷态离子与表面相互作用的原子物理平台的重要意义和将要开展的工作.The interaction between highly charged ions and surface is investigated, the mechanisms for emissions of electrons, photons and scattered neutral particles, negative and positive ions are reviewed. We report a new atomic physics station in ECR and our work plan. 相似文献
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在重离子加速器国家实验室ECR离子源上,成功组建了用于高电荷态离子与表面相互作用研究的原子物理实验平台;利用该实验平台,研究了用不同电荷态和不同速度的高电荷态离子与不同表面相互作用的可见光和X射线发射的情况,同时还研究了高电荷态Xe离子轰击晶体材料所引起的材料性质和表面结构变化的情况. 相似文献
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利用“二态矢量模型”详细研究了高电荷态O7+,N6+离子入射Al表面时中间里德伯态的形成过程,给出了电子被俘获至不同量子数(n A=2-7)的几率,以及电子俘获至里德伯态最可能的离子-表面距离.计算结果表明,较大的主量子数nA对应较小的里德伯态几率,因此O7+,N6+离子入射Al表面时辐射的X射线主要来源于较小的n A至基态的退激.为了验证计算结果,测量了O7+,N6+离子入射Al表面的X射线发射谱,并运用FAC程序计算了不同高里德伯态退激到基态的跃迁能(np–1s).实验测量到O,N的K-X射线峰,其特征峰的中心值接近主量子数n=2至n=1的跃迁能,说明发射的X射线主要来源于2p–1s的跃迁,与“二态矢量模型”理论计算的几率一致. 相似文献
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高电荷态离子与原子碰撞激发原子碰撞物理实验是在研究微观粒子的结构、能级、碰撞过程、能量输运过程的基础上发展起来的.通过粒子与原子的碰撞,使我们对原子的内部结构有更进一步的了解.例如:卢瑟福由α粒子的碰撞实验发现原子中心有一个核,从而他提出了核式原子模... 相似文献
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本文报道了He2 ,O2 和Ne2 与W靶表面相互作用中的动能电子产额随离子入射速度变化的实验测量结果.结果表明:在本实验的入射速度范围内,对同一入射离子,动能电子产额随入射离子的速度增大而线性增加.基于动能电子发射的机理,我们分析了影响动能电子产额的因素,理论上得出动能电子产额与入射速度增长呈线性增加的关系,取得了实验上和理论上一致的结果. 相似文献
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简要描述了慢速(v<vBohr)高电荷态离子与表面相互作用过程中的电子、光子发射过程.介绍了用于高电荷态离子与表面作用实验研究的目前兰州近物所的实验装置和取得的一些初步实验结果. 相似文献
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Theoretical calculations employing the modified over-barrier model to investigate single and double ionization cross sections of helium in collisions with highly charged ions are presented in the strong perturbation region. It shows the velocity and charge state dependences of cross sections, which coincides with the available experimental data. In order to determine the reliability of this model for partially stripped projectiles, the cross-section ratios have been measured for CZp+, OZp+-He (Zp=1-4) by the coincidence technique in the velocity range of 1-4.5 a.u. The calculated results are approximately in agreement with the experimental data. 相似文献
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Commercial PTFE and soda lime glass were irradiated by keV O3+ and F4+. After irradiation, in contrast to the decrease of contact angle on PTFE, contact angle on glass increased apparently. SEM observation revealed that irradiation did not cause noticeable change in surface topological structure. XPS was used to investigate chemical structure changes on the surface. Defluorination effect and formation of oxygen containing group caused by irradiation were considered to the reason of more hydrophilic PTFE surface. On the surface of irradiated glass, more carbon contaminations were observed. The differences of underlying physical and chemical processes between the two kinds of samples are discussed. 相似文献
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The guiding of 60 keV O6+ions along capillaries in an Al2O3 membrane is studied.The charge state distribution and the angular distribution of the ions transmitted through the capillaries are measured.The ion guiding ability of the concerned capillaries for the used projectile ions is analyzed,and is compared with other results using PC and alumina capillaries.Qualitative agreement is found.Further studies on material influence on the ion guiding power of the capillaries are needed. 相似文献
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Flux of X-ray radiation emitted from the Ta plasma, produced by the fundamental (1ω) and the third harmonic (3ω) frequencies of the high-power iodine laser PALS, was studied in dependence on the laser focus position. One or two (three) maxima, corresponding to the hard or soft component of the emitted spectrum, can appear, according to the experimental conditions. These dependencies are compared with those published by other authors, and also with our results concerning the highly charged ion generation. At laser intensities above I L~ 1014 W/cm2, the participation of non-linear processes in the pre-formed plasma was confirmed. 相似文献
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Rajesh Kumar S. Asad Ali A. H. Naqvi H. S. Virk Udayan De D. K. Avasthi Rajendra Prasad 《Indian Journal of Physics》2009,83(7):969-976
A wide variety of material modifications in polymers have been studied by using ion irradiation techniques. Extensive research
has focused on to Swift Heavy Ions (MeV’s energy), probably because of good controllability and the large penetration length
in polymers. High energy ion irradiation tends to damage polymers significantly by electronic excitation and ionization. It
may result into the creation of latent tracks and can also cause formation of radicals such as ablation, sputtering, chain
scission and intermolecular cross-linking, creation of triple bonds and unsaturated bonds and loss volatile fragments. Polypropylene
polymer films of thickness 50 μm were irradiated to the fluences of 1 × 1010, 3 × 1010, 1 × 1011, 3 × 1011, 6 × 1011 and 1 × 1012 ions/cm2 with Si8+ ions of 100 MeV energy from Pelletron accelerator at Inter University Accelerator Centre (IUAC), New Delhi and Ne6+ ions of 145 MeV to the fluences of 108, 1010, 1011, 1012 and 1013 ions/cm3 from Variable Energy Cyclotron Centre, Kolkata. Optical modifications were characterized by UV towards the red end of the
spectrum with the increase of the fluence. Value of optical band gap E
g
shows a decreasing trend with ion fluence irradiated with both kinds of ions. Cluster size N, the number of carbon atoms per conjugation length increases with increasing ion dose. Cluster size also increases with the
increase of electronic stopping power.
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利用经典导心轨道程序ORBIT,结合平衡程序EFIT和输运程序TRANSP,计算了EAST中性束注入后快离子的损失情况.结果表明,4MW(80keV)氘离子的损失份额为29%,2MW(50keV)氘离子的损失份额为31%,损失的快离子有很强的局域性. 相似文献