首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到10条相似文献,搜索用时 140 毫秒
1.
The crossed molecular beam technique is used for producing C60- species through potassium-buckyball collision processes, and studying the collision dynamics in an energy ranging from 10 eV up to 500 eV. At low collision energies only the negative parent ion is formed. As long as the collision energy is increased the fragmentation pattern of the fullerene negative ion could be identified and relative total cross-sections could be measured. Surprisingly, some satellite contributions have been observed in the band structure of C60- parent ion time-of-flight spectrum, which points to the existence of distinct conformational C60- isomers, which are likely to be formed during the collision, favoured by the strong polarization of the C60- in the presence of the K+ projectile ion. Such presumed detection of different spheroidal metastable C60- conformers was made possible due to an electric effect operating at the nanoscale.  相似文献   

2.
In an experimental study, the multi-ionisation of metallic clusters (Nan) has been analysed in collisions with light ions in low charge states (H+, He+, He2+, O3+) at collision velocities below 1 a.u. Cluster ions are produced in charge states up to 5+. The average charge of the nano-particles is found to increase linearly with the variation of projectile velocity and the square of the effective projectile charge, well in agreement with the electronic stopping power of the bulk material. A fraction of 50% to 30% of the total projectile energy loss (decreasing with velocity) is transferred into vibrational modes in good agreement with recent theoretical predictions. Received 8 November 2000 and Received in final form 26 January 2001  相似文献   

3.
李大万  潘广炎  杨锋 《物理学报》1996,45(9):1444-1449
用发射光谱法研究了同种元素氮的分子离子N+2和原子离子N+与Ne原子碰撞产生的激发态,获得了靶激发、入射分子离子的分解激发、入射原子离子的激发以及两种离子与靶之间的电荷转移激发等信息.计算了各发射谱线的发射截面.对两种离子引起的谱线发射截面的差异进行了分析,得出一些初步结论,并对此作了些定性解释  相似文献   

4.
The intensity and the energy distribution of Si+n cluster ions emitted from clean silicon have been measured for different target orientations as a function of the primary ion energy (3–30 keV) and the projectile mass (noble gas ion bombardment). The results favour the idea that clusters are emitted as such rather than being produced by vacuum recombination of individually emitted atoms and ions.  相似文献   

5.
The energy spectra of ions transmitted through ultrathin diamond-like foils irradiated by H+, H+2, and H+3 ions with energies from 2 to 12 keV/nucleon are studied. For molecular ions incident on the target with identical velocities, a considerable broadening of the energy spectrum is observed with an increase in the ion mass. The spectrum halfwidth reduced to the identical particle velocity remains constant for each type of incident ion, irrespective of the foil thickness.  相似文献   

6.
本文通过光学方法,在q×(20—140)keV能量范围内,研究了He+和He2+离子与碱金属原子Na碰撞中的靶激发过程。通过光学多道分析系统(OMA),对He+与Na碰撞过程,观察到NaI589.0+589.6nm(3p→3s),NaI818.3nm(3d→3p)和NaI568.8nm(4d→3p)等谱线。对He2+与Na碰撞过程,只观察到NaI589.0+589.6nm谱线。计算了所有观察到的谱线的发射截面和Na(3 关键词:  相似文献   

7.
Theoretical calculations using the coupled angular modes (CAM) method have been used to interpret experimental findings related to the scattered oxygen negative ion fraction (O) in collisions of low energy O+ with an Al(1 1 0) surface. The increasing O ion fraction observed experimentally at low O+ velocities can be explained in terms of the distance of closest approach Zc to the Al surface and the specific charge state of the projectile at this distance. Both Zc and the charge state influence the charge transfer process between the projectile and the surface at low collision energies.  相似文献   

8.
The intensities of hydrogen Hβ and deuterium Dβ spectral lines of the Balmer series were measured as a function of collision energy when H+, H2 +, H3 +, D+, D2 +, and D3 + ions impinged on Al, Ti, Cu, Mo, W, and Pb targets. The collision energies were kept in the 100–1000 eV range. The target surface was contaminated with hydrocarbons from the vacuum pumping system and possibly also by oxygen molecules due to limited vacuum conditions. At projectile velocities above 200 km/s the luminescence of backscattered deuterium atoms is about 30–50% weaker than that of hydrogen atoms.  相似文献   

9.
10.
A new analytical potential energy function for diatomic molecular ion XY+ is proposed based on the energy consistent method (ECM). The Coulomb potential included in the new ionic potential contains multipole corrections, converges quickly and is variationally, changeable. The new potential and the ECM are applied to variationally studying the potential energies of eight electronic states of several diatomic molecular ions: the A2π state of CO+, the X2g+ state of Li2+, the X2g+ state of He2+, the 12u state of Na2+, the A2u state of N2+, the X1+ state of KrH+, the X2+ state of SiO+ and the A2π state of SO+ ion. The present results agree excellently with the experiment-based Rydberg-Klein-Rees (RKR) potentials, and are superior to the commonly used Huxley-Murrell-Sorbie (HMS) analytical potentials, and are better in some cases than some quantum mechanicalab initio potentials in the ionic asymptotic and dissociation regions.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号