We present a model that elucidates the physics underlying the generation of an electromagnetic pulse from a femtosecond laser induced plasma channel. The radiation pressure force from the laser pulse spatially separates the ionized electrons from the heavier ions and the induced dipole moment subsequently oscillates at the plasma frequency and radiates an electromagnetic pulse.

We study relativistically expanding electromagnetic fields of cylindrical geometry. The fields emerge from the side surface of a cylinder and are invariant under translations parallel to the axis of the cylinder. The expansion velocity is in the radial direction and is parametrized by v = R/(ct). We consider force-free magnetic fields by setting the total force the electromagnetic field exerts ...

Can the wavelength of a classical electromagnetic field be arbitrarily small, or its electric field strength be arbitrarily large? If we require that the radiationreaction force on a charged particle in response to an applied field be smaller than the Lorentz force we find limits on the classical electromagnetic field that herald the need for a better theory, i.e., one in better accord with exp...

Abstract—This paper presents new semi-analytical expressions to calculate the self-inductance and the electromagnetic force for a ferromagnetic cylinder of finite length placed inside a circular coil of rectangular cross section. The proposed analytical model is based on boundary value problems with Fourier analysis. Laplace’s and Poisson’s equations are solved in each region by using the separ...

This paper proposes a design methodology for linear actuators, considering thermal and electromagnetic coupling with geometrical and temperature constraints, that maximizes force density and minimizes force ripple. The method allows defining an actuator for given specifications in a step-by-step way so that requirements are met and the temperature within the device is maintained under or equal ...

Can the wavelength of a classical electromagnetic field be arbitrarily small, or its electric field strength be arbitrarily large? If we require that the radiationreaction force field be smaller than the Lorentz force we find limits on the classical electromagnetic field that herald the need for a better theory, i.e., one in better accord with experiment. The classical limitations find ready in...

A novel method of combined argon gas stirring and bottom-rotating electromagnetic stirring in a ladle refining process is presented in this report. A three-dimensional numerical model was adopted to investigate its effect on improving flow field, eliminating temperature stratification, and homogenizing concentration distribution. The results show that the electromagnetic force has a tendency to...

Investigations for the melt growth gallium-antimonide (GaSb) semiconductor crystals are underway at the US Air Force Research Laboratory at Hanscom Air Force Base by the vertical gradient freeze (VGF) method utilizing a submerged heater. Electromagnetic stirring can be induced in the gallium-antimonide melt just above the crystal growth interface by applying a weak radial electric current in th...

Electromagnetic forces on three-phase five-wire (3P5W) busbar system is investigated under three-phase shortcircuits current. The conductor busbar placed in compact galvanized steel enclosure is in the rectangular shape. Transient analysis from Opera-2D is carried out to develop the model of three-phase shortcircuits current in the system. The result of the simulation is compared with the calcu...