scholarly journals Propagation of a Gaussian-top-hat function: Self-focusing properties

2022 ◽  
pp. 105118
Author(s):  
Jorge A. Anaya-Contreras ◽  
Arturo Zúñiga-Segundo ◽  
David Sánchez-de-la-Llave ◽  
Héctor M. Moya-Cessa
2021 ◽  
Author(s):  
Suo Qiangbo ◽  
Yiping Han ◽  
Zhiwei Cui

Abstract The self-focusing properties of the Laguerre-Gaussian (LG) beam in nonlinear plasma, characterized by significant collisional or ponderomotive nonlinearity have been explored. The second-order differential equation of the beam width is established from Maxwell’s equations with Wentzel–Kramers–Brillouin (WKB) and paraxial like approximation. The effect of the vortex charge number, intensity parameter and plasma temperature on the self-focusing properties of the Laguerre-Gaussian beam has been investigated.


Author(s):  
John W. Andrew ◽  
F.P. Ottensmeyer ◽  
E. Martell

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.


1970 ◽  
Vol 100 (3) ◽  
pp. 519-520 ◽  
Author(s):  
G.A. Askar'yan ◽  
V.B. Studenov ◽  
I.L. Chistyi
Keyword(s):  

Author(s):  
L. Shah ◽  
J. Tawney ◽  
A. Zoubir ◽  
M. Richardson ◽  
K. Richardson

2017 ◽  
Vol 58 (1) ◽  
pp. 46-59 ◽  
Author(s):  
Karen Pennesi

Newcomers to Canada whose names index identities other than “white” and “English” face pressure to alter their names to facilitate integration. Some immigrants oppose the forces of conformity and refuse to assimilate their names. In interviews, they explain this stance using discourses of agency centring on a belief in true names, a moral obligation to get names right, and a need for a strong self. Focusing on ideologies of identity and language in their meta-agentive discourses, I argue that the act of immigrants keeping their ethnic names is a political move to redistribute responsibility for the integration of newcomers into the host society.


2003 ◽  
Vol 296 (1) ◽  
pp. 9-18
Author(s):  
C. Hesse ◽  
D. Wolfersberger ◽  
N. Fressengeas ◽  
G. Kugel

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