Development of the spin‐polarized atom‐surface scattering method for characterizing surface magnetism: detection efficiency of the microchannel plate

Abstract

The energy, charge and angle dependence of the detection efficiency of the microchannel plate (MCP) for caesium (Cs) atoms and ions was studied for measuring the spin asymmetry of the ionization probability in the atom-surface scattering process. Based on the model of a spin-dependent scattering of a spin-polarized and energy-tunable Cs atomic beam at a magnetic surface, we have developed a new experimental method for characterizing surface magnetism.

Quantifying electron transfer during hyperthermal scattering of C60+ from Au(111) and n-alkylthiol self-assembled monolayers

“…In contrast, scattering of C 60 2+ from a C 16 SAM at E coll = 300 eV and in = 75°leads to much more effective electron transfer. In fact, the resulting charge distribution was indistinguishable from that observed when scattering C 60 + from a C 16 SAM using the same collision energy and angle ͑see Fig.…”

“…This assumption is further supported by a recent study showing that Cs and Cs + impacting onto a MCP detector at similar kinetic energies to those used in this work are detected with equal efficiencies. 16 Incident cations were generated by 100-300 eV electron impact ionization of C 60 ͑gold grade, Hoechst͒ emanating from an effusive beam oven. Resulting positively charged ions were then pulse extracted into TOF1.…”

Nanosecond control and high-density production of spin-polarized hydrogen atoms

“…1 Examples include studies of the spinstructure of the proton, 2 proposals for the production of spin-polarized anti-protons, 3 uses in nuclear fusion, 4 and the characterization of surface magnetism from surface scattering and chemisorption. 5,6,7 However, despite the fact that hydrogen is the simplest atom and is a natural choice for fundamental studies of spin-dependent collision processes, many such experiments are particularly challenging because of difficulties in both the production and the detection of SPH, especially optically, 8 due to the sub-Doppler spin-orbit splitting of the 2p state at room temperature, and the difficulty in producing intense continuous wave 121.6 nm light for optical pumping of the 2p1s transition. 9 For collision experiments, conventional methods for SPH production use large and involved experimental setups, such as Stern-Gerlach separation, 10,11 or spin-exchange optical pumping, 1 that achieve densities of only up to about 10 12 cm -3 .…”

Dynamics of spin exchange in alkali atom‐surface scattering

“…In order to study the spin correlation of the topmost layer of surfaces, we have been developing a new experimental method by means of scattering of spinpolarized alkali atoms at the magnetic surfaces. [1,2] The concept of this method is based on the spin selectivity in the electron exchange during the scattering process such as the resonant electron transfer, the spin exchange with surface electrons, the Auger electron emission, and the direct spin exchange between nucleus and electrons. In this paper, we focus on the resonant charge transfer process.…”