Beam Stop for Electron Accelerator Beam Characterisation

2009 ◽  
Vol 56 (4) ◽  
pp. 2330-2335
Author(s):  
Greg Roach ◽  
Vic Sharp ◽  
James Tickner ◽  
Josef Uher
Keyword(s):  
Electron Accelerator ◽  
Beam Stop

Single Atom Image Contrast in Fixed Beam Dark Field Electron Microscopy

1974 ◽  
Vol 32 ◽  
pp. 366-367
Author(s):  
Wah Chi
Keyword(s):  
Scattering Amplitude ◽  
Present Report ◽  
Dark Field ◽  
Image Contrast ◽  
Single Atom ◽  
Optical Theorem ◽  
Hartree Fock ◽  
Heavy Atoms ◽  
Beam Stop ◽  
Fixed Beam

Resolution and contrast are the important factors to determine the feasibility of imaging single heavy atoms on a thin substrate in an electron microscope. The present report compares the atom image characteristics in different modes of fixed beam dark field microscopy including the ideal beam stop (IBS), a wire beam stop (WBS), tilted illumination (Tl) and a displaced aperture (DA). Image contrast between one Hg and a column of linearly aligned carbon atoms (representing the substrate), are also discussed. The assumptions in the present calculations are perfectly coherent illumination, atom object is represented by spherically symmetric potential derived from Relativistic Hartree Fock Slater wave functions, phase grating approximation is used to evaluate the complex scattering amplitude, inelastic scattering is ignored, phase distortion is solely due to defocus and spherical abberation, and total elastic scattering cross section is evaluated by the Optical Theorem. The atom image intensities are presented in a Z-modulation display, and the details of calculation are described elsewhere.

Optical Properties of HVEM Accelerators

1975 ◽  
Vol 33 ◽  
pp. 180-181
Author(s):  
A. Strojnik ◽  
J.W. Scholl ◽  
V. Bevc
Keyword(s):  
Optical Properties ◽  
Electron Accelerator ◽  
Systematic Investigation ◽  
Electron Source ◽  
High Brightness ◽  
The Past ◽  
Wide Range ◽  
Optical Behavior

The electron accelerator, as inserted between the electron source (injector) and the imaging column of the HVEM, is usually a strong lens and should be optimized in order to ensure high brightness over a wide range of accelerating voltages and illuminating conditions. This is especially true in the case of the STEM where the brightness directly determines the highest resolution attainable. In the past, the optical behavior of accelerators was usually determined for a particular configuration. During the development of the accelerator for the Arizona 1 MEV STEM, systematic investigation was made of the major optical properties for a variety of electrode configurations, number of stages N, accelerating voltages, 1 and 10 MEV, and a range of injection voltages ϕ0 = 1, 3, 10, 30, 100, 300 kV).

CONSTRUCTION AND TEST OF A CHANNELING-RADIATION SOURCE AT THE NEW DARMSTADT SUPERCONDUCTING ELECTRON ACCELERATOR

1987 ◽  
Vol 48 (C9) ◽  
pp. C9-95-C9-98
Author(s):  
W. LOTZ ◽  
H. GENZ ◽  
A. RICHTER ◽  
W. KNÜPFER ◽  
J. P.F. SELLSCHOP
Keyword(s):  
Radiation Source ◽  
Electron Accelerator ◽  
Channeling Radiation

Powerful electron accelerator for the production of neutrons and radioisotopes

2019 ◽  
Vol 2019 (4) ◽  
pp. 142-152
Author(s):  
Elena Aleksandrovna Onischuk ◽  
Yurij Aleksandrovich Kurachenko ◽  
Evgenij Sergeevich Matusevich
Keyword(s):  
Electron Accelerator ◽  
Powerful Electron

scholarly journals Beam-based sub-THz source at the CERN linac electron accelerator for research facility

2019 ◽  
Vol 22 (2) ◽  
Author(s):  
A. Curcio ◽  
M. Bergamaschi ◽  
R. Corsini ◽  
D. Gamba ◽  
W. Farabolini ◽  
...  
Keyword(s):  
Electron Accelerator ◽  
Research Facility
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