Excitation of solid electrons and energy deposition induced by cluster ions

固体电子的激发和簇离子引起的能量沉积

• 批准号: 10650060
• 负责人: KANEKO Toshiaki
• 金额: $ 0.77万
• 依托单位: Okayama University of Science
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1998
• 资助国家: 日本
• 起止时间: 1998 至 1999
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-10650060/
• 关键词: cluster ions; energy-loss; cluster-number effect; wave-packet model; electronic stopping-power; dynamical dielectric function; carbon foil; average charge; 波東モデル; 誘電関数

This research is devoted to the theoretical study of interaction of cluster ions a and solids. First, we calculated the energy loss ratio R=ΔE(Bn)/(4ΔE(B)), for boron cluster ions Bn+ (n=2-4) with the kinetic energy 0.8 MeV/atom in carbon foil. The experimental data by Narumi et al. Showed the cluster effect, R>1, for any cluster size. The calculated results showed that only the perpendicular-orientation case (I. E., the atomic plane of a cluster is normal to the direction of motion) could nearly reproduce the data well, and that other cases (the randomly-oriented case and the parallel case) are far from the data. Moreover in the case of B2+, even the perpendicular case failed to get agreement with the data trend. This reason is partly due to the fact that the internuclear distance between two B ions is considerably larger (2.322Å=4.465aィイD20ィエD2) than other clusters (2.95aィイD20ィエD2). Newt, we investigated the influence of the cluster structure (a linear-chained and a rhombic C4+ ion) on the energy loss in carbon foil. At velocities greater than 2(a.u.), the energy-loss ratio, ΔE(C4)/(4ΔE(C)), for the rhombic is larger than for the linear and decreases more steeply with increasing the foil thickness. Regarding the diatomic molecular ions N2+, the energy loss in thin foils will reflect the pre-equilibrium charge state in the reduction of the energy-loss ratio. Finally we proposed the new model which could explain the reduction of the cluster average charge compared with the single-ion charge with the same velocity. Especially the cluster-size dependence and the foil-thickness dependence obtained by Brunelle et al. Could be reproduced well. The key idea is the binding effect of the surrounding ions in the cluster. It is found that the inclusion of the reduction of the average cluster charge still shows the cluster effect in the energy-loss.

本研究致力于团簇离子与固体相互作用的理论研究。首先计算了动能为0.8MeV/atom的硼团簇离子Bn+（n=2-4）在碳箔中的能量损失比R=ΔE（Bn）/（4ΔE（B））。Narumi等人的实验数据表明，对于任何簇大小，都存在簇效应，R>1。计算结果表明，只有平行取向的情况（I。E、团簇的原子平面垂直于运动方向）几乎可以很好地再现数据，而其他情况（随机取向的情况和平行的情况）则远离数据。此外，在B2+的情况下，即使是垂直的情况下，也未能得到与数据趋势一致。这部分是由于两个B离子之间的核间距（2.322 π = 4.465 α π D20 π D2）比其他团簇（2.95 α π D20 π D2）大得多。Newt的研究中，我们研究了团簇结构（线性链状和菱形C4+离子）对碳箔中能量损失的影响。在大于2（a.u.）的速度下，斜方波的能量损失比ΔE（C4）/（4ΔE（C））大于直线波，且随箔厚的增加而急剧减小。对于双原子分子离子N ~（2+），薄膜中的能量损失反映了能量损失比减小时的预平衡电荷状态。最后，我们提出了一个新的模型，它可以解释团簇平均电荷与相同速度的单离子电荷相比的减少。特别是Brunelle等人获得的簇大小依赖性和箔厚度依赖性可以很好地重现。其关键思想是簇中周围离子的结合效应。计算结果表明，在能量损失中，考虑团簇平均电荷的减少仍然表现出团簇效应。

项目成果

Toshiaki Kaneko: "Energy-loss of swift boron and carbon clusters in solids" Nuclear Instruments and Methods in Physics Research B. (1999)

Toshiaki Kaneko：“固体中快硼和碳簇的能量损失”核仪器和物理研究方法 B. (1999)

T.Takamoto, T.Kaneko: "Energy loss of molecular ions penetrating solids"Nuclear Instruments and Methods in Physics Research B. 153. 21-25 (1999)

T.Takamoto、T.Kaneko：“分子离子穿透固体的能量损失”物理研究中的核仪器和方法 B. 153. 21-25 (1999)

T.Kaneko: "Energy-loss of swift boron and carbon clusters in solids"Nuclear Instruments and Methods in Physics Research B. 153. 15-20 (1999)

T.Kaneko：“固体中快速硼和碳簇的能量损失”物理研究中的核仪器和方法 B. 153. 15-20 (1999)

T.Takamoto and T.Kaneko: "Energy loss of molecular ions penetrating solids"Nuclear Instruments and Methods in Physics Research B. 153. 21-25 (1999)

T.Takamoto 和 T.Kaneko：“分子离子穿透固体的能量损失”物理研究中的核仪器和方法 B. 153. 21-25 (1999)

T. Kaneko: "Energy-loss of swift boron and carbon clusters in solids"Nucl. Instr. Meth in Phys. Res. B. 153. 15-20 (1999)

T. Kaneko：“固体中快速硼和碳簇的能量损失”Nucl。