High-resolution photoemission study of the low-energy excitations in 4f-electron systems

1990 ◽  
Vol 42 (14) ◽  
pp. 8864-8881 ◽  
Author(s):  
F. Patthey ◽  
J.-M. Imer ◽  
W.-D. Schneider ◽  
H. Beck ◽  
Y. Baer ◽  
...  
Keyword(s):  
High Resolution ◽  
Low Energy ◽  
Electron Systems ◽  
Photoemission Study

High-Resolution Photoemission Study of the Low-Energy Excitations Reflecting the Superconducting State of Bi-Sr-Ca-Cu-O Single Crystals

1989 ◽  
Vol 62 (3) ◽  
pp. 336-339 ◽  
Author(s):  
J. -M. Imer ◽  
F. Patthey ◽  
B. Dardel ◽  
W. -D. Schneider ◽  
Y. Baer ◽  
...  
Keyword(s):  
High Resolution ◽  
Single Crystals ◽  
Superconducting State ◽  
Low Energy ◽  
Photoemission Study

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.

scholarly journals The usefulness of SwiftScan technology for bone scintigraphy using a novel anthropomorphic phantom

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Takayuki Shibutani ◽  
Masahisa Onoguchi ◽  
Yuka Naoi ◽  
Hiroto Yoneyama ◽  
Takahiro Konishi ◽  
...  
Keyword(s):  
High Resolution ◽  
Bone Scintigraphy ◽  
Low Energy ◽  
Acquisition Time ◽  
Emission Computed Tomography ◽  
Blend Ratio ◽  
Planar Image ◽  
Spect Image ◽  
Step And Shoot ◽  
Spect Images

AbstractThe aim of this study was to demonstrate the usefulness of SwiftScan with a low-energy high-resolution and sensitivity (LEHRS) collimator for bone scintigraphy using a novel bone phantom simulating the human body. SwiftScan planar image of lateral view was acquired in clinical condition; thereafter, each planar image of different blend ratio (0–80%) of Crality 2D processing were created. SwiftScan planar images with reduced acquisition time by 25–75% were created by Poisson’s resampling processing. SwiftScan single photon emission computed tomography (SPECT) was acquired with step-and-shoot and continuous mode, and SPECT images were reconstructed using a three-dimensional ordered subset expectation maximization incorporating attenuation, scatter and spatial resolution corrections. SwiftScan planar image showed a high contrast to noise ratio (CNR) and low percent of the coefficient of variance (%CV) compared with conventional planar image. The CNR of the tumor parts in SwiftScan SPECT was higher than that of the conventional SPECT image of step and shoot acquisition, while the %CV showed the lowest value in all systems. In conclusion, SwiftScan planar and SPECT images were able to reduce the image noise compared with planar and SPECT image with a low-energy high-resolution collimator, so that SwiftScan planar and SPECT images could be obtained a high CNR. Furthermore, the SwiftScan planar image was able to reduce the acquisition time by 25% when the blend ratio of Clarity 2D processing set to more than 40%.

High resolution neutron scattering study of low-energy magnetic excitations in Nd2-xCexCuO4

2010 ◽  
Vol 508 (2) ◽  
pp. 197-202
Author(s):  
M. Loewenhaupt ◽  
A. Metz ◽  
N. M. Pyka ◽  
D. McK. Paul ◽  
J. Martin ◽  
...  
Keyword(s):  
High Resolution ◽  
Neutron Scattering ◽  
Low Energy ◽  
Magnetic Excitations ◽  
Scattering Study ◽  
Neutron Scattering Study

Interaction Between Basal Stacking Faults and Prismatic Inversion Domain Boundaries in GaN

2000 ◽  
Vol 639 ◽  
Author(s):  
Philomela Komninou ◽  
Joseph Kioseoglou ◽  
Eirini Sarigiannidou ◽  
George P. Dimitrakopulos ◽  
Thomas Kehagias ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Stacking Faults ◽  
High Resolution Electron Microscopy ◽  
High Energy ◽  
Low Energy ◽  
Inversion Domain ◽  
Resolution Electron ◽  
Domain Boundaries ◽  
Inversion Domain Boundaries

ABSTRACTThe interaction of growth intrinsic stacking faults with inversion domain boundaries in GaN epitaxial layers is studied by high resolution electron microscopy. It is observed that stacking faults may mediate a structural transformation of inversion domain boundaries, from the low energy types, known as IDB boundaries, to the high energy ones, known as Holt-type boundaries. Such interactions may be attributed to the different growth rates of adjacent domains of inverse polarity.

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