scholarly journals Optimization design of electric field potential for high-speed EMU high voltage box

2021 ◽  
Vol 1865 (2) ◽  
pp. 022065
Author(s):  
Ming Zhao
1996 ◽  
Vol 14 (12) ◽  
pp. 1356-1361 ◽  
Author(s):  
M. A. Volkov ◽  
A. A. Namgaladze

Abstract. We have used the global numerical model of the coupled ionosphere-thermosphere-protonosphere system to simulate the electric-field, ion- and electron-temperature and -concentration variations observed by EISCAT during the substorm event of 25 March 1987. In our previous studies we adopted the model input data for field-aligned currents and precipitating electron fluxes to obtain an agreement between observed and modelled ionospheric variations. Now, we have calculated the field-aligned currents needful to simulate the substrom variations of the electric field and other parameters observed by EISCAT. The calculations of the field-aligned currents have been performed by means of numerical integration of the time-dependent continuity equation for the cold magnetospheric electrons. This equation was added to the system of the modelling equations including the equation for the electric-field potential to be solved jointly. In this case the inputs of the model are the spatial and time variations of the electric-field potential at the polar-cap boundaries and those of the cold magnetospheric electron concentration which have been adopted to obtain the agreement between the observed and modelled ionospheric variations for the substorm event of 25 March 1987. By this means it has been found that during the active phase of the substorm the current wedge is formed. It is connected with the region of the decreased cold magnetospheric electron content travelling westwards with a velocity of about 1 km s–1 at ionospheric levels.


2015 ◽  
Vol 28 (2) ◽  
pp. 261-283 ◽  
Author(s):  
YOUCEF AMIRAT ◽  
VLADIMIR V. SHELUKHIN

We study the two-scale homogenization of the diffraction interfacial condition for the diffusion equation relevant to a composite medium which has a periodic structure. The results are applied to the electric field potential within a dielectric composite body when there is a difference in dielectric permittivity between the composite components in the presence of interfacial static charges. The principal result is that the interfacial charge distribution is equivalent to an apparent bulk charge which can be calculated starting from the composite geometry. We perform the corrector analysis and establish that the corrector terms strongly depend on the interfacial charge.


2016 ◽  
Vol 94 (6) ◽  
pp. 548-557 ◽  
Author(s):  
Dehua Wang ◽  
Shaohao Cheng ◽  
Qiang Chen ◽  
Zhaohang Chen

The DC field microscopy of Rydberg Li atoms has been studied on the basis of the semiclassical theory for the first time. In particular, we discuss the atomic core scattering effect in the ionization dynamics of the Rydberg Li atom. Unlike the case of the photoionization of a Rydberg H atom in an electric field, where the photoionization microscopy interference patterns are mainly caused by the Coulomb scattering and the electric field potential, for the photoionization of a Rydberg Li atom in an electric field, the influence of the atomic core scattering effect on the photoionization microscopy interference patterns plays an important role. In addition, the structure of the interference pattern, which contains the spatial component of the electronic wave function, evolves smoothly with the electron energy above the saddle point energy. The observed oscillatory patterns in the electron probability density distributions on the detector plane are interpreted within the framework of the semiclassical approximation, which can be considered as a manifestation of interference between various electron trajectories arriving at a given point from the atom to the detector plane. This study provides some reference values for future experimental research on photoionization microscopy of the non-hydrogen Rydberg atoms in the presence of external fields.


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