Zhang Xiao-An

Surface Plasmon-Assisted Excitation of Atomic Visible Light Spectral Lines in the Impact of Highly Charged Ions 126Xeq + on Solid Surfaces

We measured the visible light spectral lines of sputtering atoms from solid surfaces of Al, Ti, Ni, Ta and Au which are impacted by 150 keV 126Xeq + (6≤q≤30). It is found that intensities of the light spectral lines are greatly and suddenly enhanced when the charge state of the ion is raised up to a critical value. If assuming that potential energy released from the incident ion due to capturing one electron is enough to excite a surface plasmon, we can estimate the critical charge states and obtain the results very well consistent with the measurements for the above-mentioned target materials. This means that a surface plasmon induced by one electron capture can enhance the excitation of atomic visible light spectral lines in the impact of a highly charged ion on a solid surface.

Oscillator Strength for n = 2 Transitions in Highly Ionized Sulfur

Oscillator strength f-values for L-shell transitions in highly ionized sulfur are studied by the beam-foil technique at the HI-13 tandem accelerator in China Institute of Atomic Energy. The lifetimes of the upper levels 2s2p P-1(1)o, 2p(2) S-1(0), 2p(2) P-3(1), 2p(2) P-3(2), 2p(2) P-3(0) of Be-like sulfur are measured to be 129 +/- 4, 81 +/- 5, 165 +/- 7, 159 +/- 8, 176 +/- 11 ps. By using the measured lifetimes, the f-values are calculated to be 0.074, 0.082, 0.060, 0.066, 0.229, 0.056, 0.083, 0.089, 0.028 for the transitions 2s(2)2p(2) P-3(1)-2s2p(3) P-3(1)o, 2s(22)p P-2(3/2)o-2s2p(2) P-2(1/2), 2s2p(2) P-4(3/2)-2p(3) S-4(3/2)o, 2s(2)2p P-2(1/2)o-2s2p(2) D-2(3/2), 2s(2) S-1(0)-2s2p P-1(1)o, 2s2p(1) P-1(o)-2p(2) S-1(0), 2s2p(3) P-0(o)-2p(2) P-3(1), 2s2p P-3(2)o-2p(2) P-3(2) and 2s2p P-3(1)o-2p(2) P-3(0). Most of the experimental results are in agreement with theoretical studies, but differ slightly from the previous experimental data.

Kr L X-ray and Au M X-ray emission for 1.5 MeV—3.9 MeV Kr13+ ions impacting on an Au target

Kr L X-ray and Au M X-ray emission for Kr13+ ions with energies of 1.5 MeV and 3.9 MeV impacting on an Au target are investigated at heavy ion research facility in Lanzhou (HIRFL). The L-shell X-ray yield per ion of Kr is measured as a function of incident energy. In addition, Kr L X-ray production cross section is extracted from the yield and compared with the result obtained from the classical binary-encounter approximation (BEA) model. Furthermore, the intensity ratio of the Au Mβ3 to Mα1 X-ray is investigated as a function of incident energy.

X ray spectra induced by 129 Xe 30+ impacting the Au surface

X ray emission from Xe 30+ ions (kinetic energy 350-600 keV) impacting on an Au target surface was investigated. The 1.65 keV M-X ray and the Au atomic Mα characteristic X rays were measured. The results show that because the 3d electron of the Xe ion is excited to occur a vacancy, the 1.65 keV M-X ray are emit from the electron transition between 4f to 3d energy level. The 3s electron of the Au target atom is ionized to form a hole in the M-shell, the Mα characteristic X rays are radiated by 4f electron filling in the hole. It was also found that the yield of such characteristic X rays is decreasing with increasing the projectile kinetic energy. The yield of the characteristic Au X rays increases with increasing the projectile kinetic energy. These phenomena are analyzed with the classical coulomb over the barrier mode.当不同动能(350-600 keV)高电荷态离子 129 Xe 30+ 入射Au 表面过程中, 发出了1.65 keV 的X 射线和靶原子的Mα特征X 射线. 分析表明: 高电荷态离子与Au 表面相互作用过程中, Xe 离子3d 壳层的电子被激发, 形成空穴, 4f 电子偶极跃迁辐射1.65 keV M-X 射线. 同时, 靶原子Au 的3s 电子被激发, 退激辐射Mα X 射线. 利用经典过垒模型解释了Xe 的M-X 射的产额随入射离子的动能增加而减小, 靶原子的特征X 射线产额随入射离子的动能增加而增加的原因.

K shell hyper-satellite lines of Cu induced by 300MeV/u C ions

X-ray emission induced by 300 MeV/u C ions impacting on copper was investigated at the Heavy Ion Research Facility in Lanzhou (HIRFL). The results showed a very high yield of K hyper-satellite emission comparing to the satellite emission.

Topological structure of the solitons solution in SU(3) Dunne-Jackiw-Pi-Trugenberger model

By using -mapping topological current theory and gauge potential decomposition, we discuss the self-dual equation and its solution in the SU(N) Dunne-Jackiw-Pi-Trugenberger model and obtain a new concrete self-dual equation with a δ function. For the SU(3) case, we obtain a new self-duality solution and find the relationship between the soliton solution and topological number which is determined by the Hopf index and Brouwer degree of -mapping. In our solution, the flux of this soliton is naturally quantized.