X-ray emission for Ar¹¹⁺ ions impacting on various targets in the collisions near the Bohr velocity*

Abstract

X-ray emission from the collisions of 3 MeV Ar11 + ions with V, Fe, Co, Ni, Cu, and Zn is investigated. Both the x-rays of the target atom and projectile are observed simultaneously. The x-ray yield is extracted from the original count. The inner-shell ionization cross section is estimated by the binary encounter approximation model and compared with the experimental result. The remarkable result is that the Ar K-shell x-ray yield is diminished with the target atomic number increasing, which is completely opposite to the theoretical calculation. That is interpreted by the competitive consumption of the energy loss for the ionization of inner-shell electrons between the projectile and target atom.

Electron emission induced by keV protons from tungsten surface at different temperatures

“…It can be calculated based on the x-ray counts obtained from the experiment. [4] The x-ray yield Y is expressed as…”

“…The underlying physical processes are very important for not only basic physics, but also technical applications, such as material surface modification, x-ray source equipment, radiation physics, plasma-wall interactions, and material surface analysis as well. [1][2][3][4][5][6][7][8] When a charged ion impacts solid target, it will deposit most of its potential energy into several atomic layers through the process of neutralization and de-excitation within femtoseconds. [3] At the same time, through inelastic collisions, the kinetic energy of the ion can be transferred into valence electrons or inner-shell electrons, resulting in the shell ionization.…”

“…As is well known, the electron emission yield is related to the charge state, velocity, incident energy, atomic number and incident angle of incident ions, and so on. [4][5][6][7][8] We have also studied the influence of state of charge of incident ion, recoil atoms, and target temperature on the electron emission yield γ. [11][12][13] Electron emission caused by highly charged ions (HCIs) is usually divided into two different mechanisms, one is the potential emission (PE) process and the other is the kinetic emission (KE) process.…”

“…[16][17][18] A lot of researches have been done to study electron emission [1][2][3][11][12][13] and x-rays. [4,19] However, there are few studies on these two phenomena at the same time. [20] We have not found the researches about the electron emission from tungsten surface at different temperatures.…”

Nd L-shell x-ray emission induced by light ions

“…The ion-atom collisions have been extensively investigated experimentally and theoretically in the past few decades to meet the requirement of fundamental research and practical applications. [1][2][3][4][5][6][7][8] During such collisions, the inner-shell electrons of projectile and target atom can be excited by the direct Coulomb ionization or charge transfer. The corresponding vacancy decays radiatively by x-ray emission or nonradiatively by Auger or Coster-Kronig (CK) transition processes.…”