We discuss theoretically the properties of an electromechanical oscillator whose operation is based upon the cyclic, quasi-conservative conversion between gravitational potential, kinetic, and magnetic energies. The system consists of a strong-pinnin
g type-II superconductor square loop subjected to a constant external force and to magnetic fields. The loop oscillates in the upright position at a frequency that can be tuned in the range 10-1000 Hz, and has induced in it a rectified electrical current. The emphasis of this paper is on the evaluation of the major remaining source of losses in the oscillations. We argue that such losses should be associated with the viscous vibration of pinned flux lines in the superconductor Nb-Ti wire, provided the oscillator is kept close to zero Kelvin, under high-vacuum, and the magnetic field is sufficiently uniform. We discuss how other different sources of loss would become negligible for such operational conditions, so that a very high quality factor Q exceeding 10^(10) might in principle be reached by the oscillator. The prospective utilization of such oscillator as a low-frequency high-Q clock is analyzed.Since publication the ideas in this paper have been explored both by the author and elsewhere, in applications covering Metrology, quantum systems, and gravimetry.
The present paper is based upon the fact that if an object is part of a highly stable oscillating system, it is possible to obtain an extremely precise measure for its mass in terms of the energy trapped in this resonance. The subject is timely since
there is great interest in Metrology on the establishment of a new electronic standard for the kilogram. Our contribution to such effort includes both the proposal of an alternative definition for mass in terms of energy, as well as the description of a realistic experimental system in which this definition might actually be applied. The setup consists of an oscillating type-II superconducting loop (the SEO system) subjected to the gravity and magnetic fields. The system is shown to be able to reach a dynamic equilibrium by trapping energy up to the point it levitates against the surrounding magnetic and gravitational fields, behaving as an extremely high-Q spring-load system. The proposed energy-mass equation applied to the electromechanical oscillating system eventually produces a new experimental relation between mass and standardized constants.
The purpose of this note is to make a brief analysis of the physical principles upon which two methods for relating the mass of an object to fundamental physical constants are based. The two methods are, namely, the watt balance method, and a still u
ntested experimental technique based upon a superconductor electromechanical oscillator. We show that both these methods are governed by similar equations.
There has been an increasing technological interest on magnetic thin films containing antidot arrays of hexagonal or square symmetry. Part of this interest is related to the possibility of domain formation and pinning at the antidots boundaries. In t
his paper, we develop a method for the calculation of the magnetic moment distribution for such arrays which concentrates on the immediate vicinity of each antidot. For each antidot distribution (square or hexagonal) a suitable system of coordinates is defined to exploit the shape of the unit-cells of the overall nanostructure. The Landau-Lifshitz-Gilbert-Brown equations that govern the distribution of moments are rewritten in terms of these coordinates. The equilibrium moments orientation is calculated for each position in a Cartesian grid defined for these new coordinate systems, and then a conformal transformation is applied to insert the moment vectors into the actual unit-cell. The resulting vector maps display quite clearly regions of different moment orientation around the antidots, which can be associated with nanoscale domains. These results are similar to the ones obtained by other authors[1-4] using the NIST oommf method.
