Polarization Potential in Low-Energy Electron-H2Scattering

1968 ◽  
Vol 173 (1) ◽  
pp. 183-190 ◽  
Author(s):  
Neal F. Lane ◽  
Ronald J. W. Henry
Keyword(s):  
Polarization Potential ◽  
Low Energy ◽  
Energy Electron ◽  
Low Energy Electron

Performance Evaluation of a Novel Type of Low-Energy Electron Microscope

1990 ◽  
Vol 48 (1) ◽  
pp. 354-355
Author(s):  
Bertholdand Senftinger ◽  
Helmut Liebl
Keyword(s):  
Electron Microscope ◽  
High Resolution ◽  
Field Strength ◽  
Numerical Aperture ◽  
Low Energy ◽  
Energy Electron ◽  
High Resolution Imaging ◽  
Lens System ◽  
Resolution Imaging ◽  
Low Energy Electron

During the last few years the investigation of clean and adsorbate-covered solid surfaces as well as thin-film growth and molecular dynamics have given rise to a constant demand for high-resolution imaging microscopy with reflected and diffracted low energy electrons as well as photo-electrons. A recent successful implementation of a UHV low-energy electron microscope by Bauer and Telieps encouraged us to construct such a low energy electron microscope (LEEM) for high-resolution imaging incorporating several novel design features, which is described more detailed elsewhere.The constraint of high field strength at the surface required to keep the aberrations caused by the accelerating field small and high UV photon intensity to get an improved signal-to-noise ratio for photoemission led to the design of a tetrode emission lens system capable of also focusing the UV light at the surface through an integrated Schwarzschild-type objective. Fig. 1 shows an axial section of the emission lens in the LEEM with sample (28) and part of the sample holder (29). The integrated mirror objective (50a, 50b) is used for visual in situ microscopic observation of the sample as well as for UV illumination. The electron optical components and the sample with accelerating field followed by an einzel lens form a tetrode system. In order to keep the field strength high, the sample is separated from the first element of the einzel lens by only 1.6 mm. With a numerical aperture of 0.5 for the Schwarzschild objective the orifice in the first element of the einzel lens has to be about 3.0 mm in diameter. Considering the much smaller distance to the sample one can expect intense distortions of the accelerating field in front of the sample. Because the achievable lateral resolution depends mainly on the quality of the first imaging step, careful investigation of the aberrations caused by the emission lens system had to be done in order to avoid sacrificing high lateral resolution for larger numerical aperture.

Low-Energy-Electron-Diffraction Structural Studies of (100) Cleavage Surfaces of In4Se3 Layered Crystals

2014 ◽  
Vol 59 (6) ◽  
pp. 612-621 ◽  
Author(s):  
P.V. Galiy ◽  
◽  
Ya.B. Losovyj ◽  
T.M. Nenchuk ◽  
I.R. Yarovets’ ◽  
...  
Keyword(s):  
Electron Diffraction ◽  
Low Energy ◽  
Energy Electron ◽  
Structural Studies ◽  
Low Energy Electron Diffraction ◽  
Layered Crystals ◽  
Low Energy Electron
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