MIDOT: A novel probe for monitoring high-current flat transmission lines

A novel inductive probe, termed MIDOT, was developed for monitoring high-current flat transmission lines. While being inexpensive the probe does not require calibration, is resistant to both shock waves and temperature variations, and it is easy to manufacture and mount. It generates strong output signals that are relatively easy to interpret and has a detection region limited to a pre-defined part of the transmission line. The theoretical background related to the MIDOT probes, together with their practical implementation in both preliminary experimentation and high-current tests, is also presented in the paper. The novel probe can be used to benchmark existing 2D numerical codes used in calculating the current distribution inside the conductors of a transmission line but can easily detect an early movement of a transmission line component. The probe can also find other applications, such as locating the position of a pulsed current flowing through a thin wire

MIDOT: A novel probe for monitoring high-current flat transmission lines

This paper was published in the journal Review of Scientific Instruments and the definitive published version is available at http://dx.doi.org/10.1063/1.4971246A novel inductive probe, termed MIDOT, was developed for monitoring high-current flat transmission lines. While being inexpensive the probe does not require calibration, is resistant to both shock waves and temperature variations, and it is easy to manufacture and mount. It generates strong output signals that are relatively easy to interpret and has a detection region limited to a pre-defined part of the transmission line. The theoretical background related to the MIDOT probes, together with their practical implementation in both preliminary experimentation and high-current tests, is also presented in the paper. The novel probe can be used to benchmark existing 2D numerical codes used in calculating the current distribution inside the conductors of a transmission line but can easily detect an early movement of a transmission line component. The probe can also find other applications, such as locating the position of a pulsed current flowing through a thin wire

Development of a Pulsed High Current Facility for Accelerating Metal Foils for Hydrodynamic Materials Testing

A new pulsed power machine to be called AMPERE is currently under development at AWE. Its initial use will be as a metallic foil accelerator for the specific purpose of applying large impulses (>300 Pa s) and pressures (>450 G Pa) to a target for material property testing. The critical circuit features are described and a computer model has been written to predict the expected machine performance. Future uses of this facility for driving further hydrodynamic experimentation are also discussed

An experimental confirmation of longitudinal electrodynamic forces

According to the conventional views of electromagnetic theory, as these are expressed in the Lorentz force law, all the forces which act on a current carrying metallic conductor are perpendicular to the current streamlines. However, over the years, from Ampère through Maxwell until the present day, there have been persistent claims that when current flows in a metallic conductor, there are mechanical forces acting along current streamlines which subject the conductor to tensile stress, and which are therefore capable of performing work in the direction of current flow. The problem of substantiating these claims has always lain in the difficulty of designing an experiment in which the effects are unambiguously demonstrated. The present paper describes an experiment which to a large extent removes these ambiguities, and which provides a compelling novel demonstration of forces acting along current streamlines. A force calculation based on Ampère's original electrodynamic force law is found to be consistent with the observed behaviour

A novel current density distribution sensor for use in parallel plate transmission lines

As part of an on-going electromagnetic flyer plate research programme, it has been established that a method to determine the current distribution (or at least confirm its uniformity) is now required to establish predictable acceleration of the flyer plate. To achieve this diagnostic capability, a bespoke sensor array has been developed, termed the MIDOT (a relative Mutual Inductance sensor array). It has been specifically developed as a method of determining the current density distribution across a thin, close coupled, parallel plate transmission line. This novel sensor has been developed to a point where the proof of principle has been successfully demonstrated on a low voltage test bed, with some preliminary high voltage shots being carried out on a bespoke experimental arrangement prior to it being fielded on the flyer plate accelerator facilities at both Loughborough University and AWE