ΔBmechanism for fringe-field organic magnetoresistance

2015 ◽  
Vol 91 (16) ◽  
Author(s):  
M. Cox ◽  
S. P. Kersten ◽  
J. M. Veerhoek ◽  
P. Bobbert ◽  
B. Koopmans
Keyword(s):  
Fringe Field ◽  
Organic Magnetoresistance

A Magnetic Spectrometer for a Scanning Transmission Electron Microscope

1974 ◽  
Vol 32 ◽  
pp. 436-437
Author(s):  
A. Kosiara ◽  
J. W. Wiggins ◽  
M. Beer
Keyword(s):  
Scanning Transmission Electron Microscope ◽  
Magnetic Spectrometer ◽  
Fringe Field ◽  
Curvature Radius ◽  
Magnetic Pole ◽  
Quadrupole Field ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Under Construction ◽  
Image Position

A magnetic spectrometer to be attached to the Johns Hopkins S. T. E. M. is under construction. Its main purpose will be to investigate electron interactions with biological molecules in the energy range of 40 KeV to 100 KeV. The spectrometer is of the type described by Kerwin and by Crewe Its magnetic pole boundary is given by the equationwhere R is the electron curvature radius. In our case, R = 15 cm. The electron beam will be deflected by an angle of 90°. The distance between the electron source and the pole boundary will be 30 cm. A linear fringe field will be generated by a quadrupole field arrangement. This is accomplished by a grounded mirror plate and a 45° taper of the magnetic pole.

An improved magnetic prism design for a transmission electron microscope energy filter

1978 ◽  
Vol 36 (1) ◽  
pp. 40-41 ◽  
Author(s):  
John W. Andrew ◽  
F.P. Ottensmeyer ◽  
E. Martell
Keyword(s):  
Energy Resolution ◽  
Symmetry Plane ◽  
Fringe Field ◽  
Focal Distance ◽  
Electron Trajectories ◽  
Focusing Effect ◽  
Transmission Electron ◽  
Path Lengths ◽  
Electron Microscopes ◽  
Focusing Properties

Energy selecting electron microscopes of the Castaing-Henry prism-mirror-prism design suffer from a loss of image and energy resolution with increasing field of view. These effects can be qualitatively understood by examining the focusing properties of the prism shown in Fig. 1. A cone of electrons emerges from the entrance lens crossover A and impinges on the planar face of the prism. The task of the prism is to focus these electrons to a point B at a focal distance f2 from the side of the prism. Electrons traveling in the plane of the diagram (i.e., the symmetry plane of the prism) are focused toward point B due to the different path lengths of different electron trajectories in the triangularly shaped magnetic field. This is referred to as horizontal focusing; the better this focusing effect the better the energy resolution of the spectrometer. Electrons in a plane perpendicular to the diagram and containing the central ray of the incident cone are focused toward B by the curved fringe field of the prism.

scholarly journals Photocontrollable Resistivity Change in Nanoparticle-Doped Liquid Crystal Alignment Layer: Voltage Holding and Discharging Properties of Fringe-Field Switching Liquid Crystal Modes

Crystals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 268
Author(s):  
Jeong-Hoon Ko ◽  
Jun-Chan Choi ◽  
Dong-Jin Lee ◽  
Jae-Won Lee ◽  
Hak-Rin Kim
Keyword(s):  
Liquid Crystal ◽  
Power Saving ◽  
Low Frequency ◽  
Fringe Field ◽  
Resistance Level ◽  
Alignment Layer ◽  
Experimental Scheme ◽  
Tunable Range ◽  
Crystal Alignment ◽  
Operation Frequency

In liquid crystal (LC) displays, deriving an optimum resistance level of an LC alignment polyimide (PI) layer is important because of the trade-off between the voltage holding and surface-discharging properties. In particular, to apply a power-saving low-frequency operation scheme to fringe-field switching (FFS) LC modes with negative dielectric LC (n-LC), delicate material engineering is required to avoid surface-charge-dependent image flickering and sticking problems, which severely degrade with lowering operation frequency. Therefore, this paper proposes a photocontrolled variable-resistivity PI layer in order to systematically investigate the voltage holding and discharging properties of the FFS n-LC modes, according to the PI resistivity (ρ) levels. By doping fullerene into the high-ρ PI as the photoexcited charge-generating nanoparticles, the ρ levels of the PI were continuously controllable with a wide tunable range (0.95 × 1015 Ω∙cm to 5.36 × 1013 Ω∙cm) through Ar laser irradiation under the same LC and LC alignment conditions. The frequency-dependent voltage holding and discharge behaviors were analyzed with photocontrolled ρ variation. Thus, the proposed experimental scheme is a feasible approach in PI engineering for a power-saving low-frequency FFS n-LC mode without the image flickering and image sticking issues.

23-1:Distinguished Student Paper: Flexoelectric Effect on Image Flickering of Fringe Field Switching LCDs

2016 ◽  
Vol 47 (1) ◽  
pp. 274-277 ◽  
Author(s):  
Haiwei Chen ◽  
Fenglin Peng ◽  
Minggang Hu ◽  
Shin-Tson Wu
Keyword(s):  
Fringe Field ◽  
Flexoelectric Effect ◽  
Student Paper

Guidage d'un faisceau de particules chargées à travers une chaîne de solénoïdes cylindriques et toroïdaux alternés

1985 ◽  
Vol 63 (8) ◽  
pp. 1098-1104
Author(s):  
Giulio Bosi ◽  
Alain Durand
Keyword(s):  
Distribution Function ◽  
Space Charge ◽  
Axial Symmetry ◽  
Fringe Field ◽  
Suitable Choice ◽  
Space Charge Effects ◽  
Electron Cooler ◽  
Charge Effects ◽  
Angular Extent ◽  
Transverse Temperature

The present paper is devoted to analyzing the magnetic fringe-field and space-charge effects on a beam of nonrelativistic electrons crossing a sequence of cylindrical and toroidal solenoids, as may be found in an electron cooler. The investigation is mainly aimed at searching for suitable conditions that ensure conservation of the axial symmetry of a given beam throughout the whole system. The need for a vertical steering field, in addition to the longitudinal one provided by each toroidal coil, is emphasized and its form determined. A suitable choice of the angular extent of a torus is shown to suppress axis vibrations at the entrance of the following sector. Finally, the transverse temperature of a cylindrical beam is calculated after specifying the appropriate distribution function.

INSTALLATION OF 1.5 T MRI ACCELERATOR NEXT TO CLINICAL ACCELERATORS: IMPACT OF FRINGE FIELD

2009 ◽  
Vol 92 ◽  
pp. S94-S95
Author(s):  
J. Kok ◽  
B. Raaymakers ◽  
H. Welleweerd ◽  
N. de Graaff ◽  
J. Overweg ◽  
...  
Keyword(s):  
Fringe Field
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