Magnetic Traveling Wave Research Articles

Magnetic Field Analysis in Shell-Like Spherical Induction Machines with Zenithal Traveling Waves

In this paper, a magnetic field analysis is done for spherical shell-like induction machines with a zenithal progressive magnetic traveling wave, using an analytical model in spherical coordinates. These analytical models have major importance in the simulation, project, and preliminary optimization of devices due to its analytical solutions and physical insight. The magnetic field analysis is made for a shell-like induction machine for the study of its electromagnetic and mechanical quantities, as the magnetic field, induced currents, and electromagnetic torque. The developed model is validated, first with a set of generic windings distributions using the results of a commercial finite element analysis (FEA) tool and, second, validated by comparing with the results from the shell-like induction machine prototype. The results obtained from the analytical model are very close to the ones obtained by the FEA tool and from the prototype tests.

Magnetic Separation and Transfer of Wastewater Contaminants Using Magnetic Traveling Wave and Micro Magnetic Bead

This paper proposes a new physical method to treat wastewater using magnetic traveling wave and micro magnetic beads. The contaminants in wastewater adhere to the micro beads with the aid of a reagent to form magnetic flocs. An experimental jar test shows adhesion between contaminants and micro beads. The magnetic flocs are separated from the wastewater and then transferred by traveling magnetic wave. A simple experiment demonstrates how this process works. A magnetic separation system for the traveling magnetic wave is designed and its performance is numerically analyzed using the electromagnetic finite-element method, which is coupled with the fluid equation and the dynamic equation of micro beads.

ANALYSIS OF FLUCTUATION FUNCTION IN TIME-GRATING AND NEW METHOD PRODUCING TRAVELLING WAVE

The principle to produce the motional coordinate in time-grating displacement sensor is analyzed.In order to sim- plify the structure of the time-grating sensor and make its manufacture easily,its fluctuation function is analyzed and the relation and distinction between electric travelling wave and magnetic travelling wave are discussed.Then a new method to produce traveling wave is proposed based on these discussions. The method is employed with its corresponding mechanical structure to form a new type time-grating sensor.Experimental results show that the sensor can generate correct signal and the method is feasible.Thus the traditional electrical machinery method can be replaced by a new method to produce the mo- tional magnetic field.This new method can simplify the manu- facture process greatly.

Circular magnetic macroparticle accelerator for impact fusion

The author proposes the use of a circular accelerator for gram-size superconducting macroparticles, with the acceleration to the velocities needed for impact fusion performed by a magnetic travelling wave. It is suggested to use the recently discovered high-Tc superconductors both for the macroparticle and for the establishment of the waveguide field. To give the macroparticle a large magnetic moment, it is proposed that it be composed of a densely packed lattice of superconducting grains embedded in a suitable insulator. Since the macroparticle can be kept in a stable orbit by a Braunbeck levitation configuration, the guide field can be static. The macroparticle can then be slowly accelerated along its circular track by a travelling magnetic wave, the field strength of which can be much weaker than the strength of the guide field so that the travelling wave can be generated by ordinary magnetic field coils. In a typical example, the accelerator would have a circumference of about 10 km and, to reach a velocity of about 200 km·s−1 as needed for impact fusion, the projectile would have to make about ten runs with an acceleration length of ∼ 100 km. For a gram-size projectile the kinetic energy would be large enough to ignite a thermonuclear microexplosion.

Travelling waves in a dielectric slab with an abrupt change in thickness

If a slab (or tube) of dielectric material of uniform thickness is surrounded by a medium of lower dielectric constant it can support travelling waves that propagate without attenuation. If there is an abrupt change in the slab thickness, reflexion and radiation will occur. This paper deals with the simplest prototype case, in which a transverse magnetic travelling wave, whose length is large compared with slab thickness, encounters such a change in geometry. At points very close to the junction the field is modelled by a quasistatic solution. An outer approximation is calculated, based on the idea of replacing the actual slab by a hypothetical surface of infinitesimal thickness, with appropriate discontinuity conditions. A solution is determined in the form of an inverse Fourier integral, and explicit results are given for the reflexion and transmission coefficients.

Black body radiation imploded inside a small cavity as an inertial confinement fusion driver

It is proposed to use black body radiation generated and imploded within a small cavity as a driver for inertial confinement fusion, with the thermonuclear target centered inside the cavity. By imploding the cavity the black body radiation confined in it is greatly amplified. The thermonuclear target placed inside the cavity in absorbing the energy from the incoming black body radiation is then ablatively imploded by this radiation. Since this radiation can have a rather short wave length, high density compression of the target seems to be attainable with relative ease. If the temperatureT in the cavity rises the energy absorbed by the target rises asT7.5 and most of the black body radiation is therefore absorbed by the target towards the end of the implosion process greatly increasing the power. To implode and thereby amplify the black body radiation inside the cavity requires a velocity not larger than ∼50 km/s. This comparatively low velocity permits to implode the cavity by laser- or charged-particle beams of modest power. The required rather low cavity implosion velocity should be also attainable using magnetic travelling wave projectile accelerators not longer than a few 100 meters, making the concept also attractive for impact fusion.

On the Acceleration of a Superconducting Macroparticle in a Magnetic Travelling Wave Accelerator

Abstract Two models for describing the operation of a magnetic travelling wave accelerator, the transmission line model and the lumped parameter model, are analyzed. For both cases the current distribution and the magnetic field are calculated. It is shown that the transmission line model can be obtained as the limiting case of the lumped parameter model. It is then assumed that a superconducting solenoid with large persistent currents is used as a projectile with a constant magnetic dipole moment. The motion of this projectile is studied in the case of ignorable flux interaction. The conditions for phase and rotational stability are obtained. It is shown that the projectile has a transverse translational instability. A derivation of the flux interaction current wave is included in the Appendix.

Magnetic acceleration of a superconducting solenoid to hypervelocities

A new method is described which promises to accelerate large macroscopic particles up to meteoric velocities and beyond. In this method a superconducting solenoid is trapped and accelerated in front of a magnetic travelling wave. The magnetic travelling wave is generated by a lumped parameter transmission line. It is demonstrated that with relatively modest accelerator dimensions velocities in the meteoric range of 106 cm/sec up to 107 cm/sec may be attainable. To reach a velocity of 108 cm/sec the length of the accelerator will be at least of the order of a few kilometres. At velocities of 108 cm/sec the controlled release of thermonuclear power should become feasible. The high pressure generated at impact should make it possible to study matter under conditions similar to those that exist in the interior of planets and stars. For velocities of 108 cm/sec and beyond it should be possible to observe the Lorentz contraction.