Measurement of the Magnetic Field Distribution in Railguns Using CMR-B-Scalar Sensors

Abstract

Colossal magnetoresistance effect B-scalar magnetic field sensors with effective areas of 0.05 mm 2 were used very close to the rails for magnetic field measurements. These measurements were performed during static and dynamic railgun experiments. In static experiments three different rail materials were used and the results are compared to a finite element simulation.

Velocity-induced current profiles inside the rails of an electric launcher

“…4 & 5), as demonstrated by the previous results published in [16] and [17]. As in the earlier works, the influence of the VSE on the measured signals is visible.…”

“…This sensor type is very small and can be used to measure the absolute value of pulsed magnetic flux densities up to 40 T. An array of such sensors was successfully used to investigate the current distribution in the rails of a railgun by measuring the magnetic field distribution in the vicinity of the rail [15]- [17]. The measurement showed the presence of the VSE.…”

“…Therefore, the measurement system was considerably improved to gain a better signal quality [18]. This paper describes the continuation of the work presented in [16] and [17]. The measurement of magnetic diffusion was continued with the newly developed equipment and results were compared to the time-harmonic FEM simulations.…”

Microwave Radar for Non-Destructive Express Testing of Electrical Properties of Semiconductor Materials

“…Discharging the capacitor bank through the pulsed coil a sinusoid shape pulse of magnetic field up to 40 T and 1-10 ms duration can be generated [16]. An amplitude and shape of generated magnetic field pulse is controlled with magnetic field sensor (for simplicity not shown) [17]. For excitation of magnetoplasmic waves 3-30 GHz generators can be used.…”

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

“…More recently, a novel and remarkable microscopic size (active surface 400 × 50 µm) scalar magnetic probe has been developed, based on the Colossal Magneto-Resistance (CMR) effect. 7 An array of such probes was successfully used for studies of the current distribution inside the parallel transmission plates of a rail gun. 7,8 However, there are a number of drawbacks that make its utilisation sometimes difficult since the probes can only accurately measure magnetic flux densities above 1.5 T, are sensitive to strong mechanical shocks and temperature variation, and lastly, but not least importantly, they are expensive to replace in unavoidable destructive experiments such as those related to slapper accelerators.…”