Pulsed magnetic field measurement for railgun investigation
When a short and high current pulse is supplied to an electric conductor, due to magnetic diffusion the current distributes inhomogeneous over cross section of the conductor. In rails of the Railgun, the skin and proximity effect leads to current concentration at the inner surface of the rail. Consequently, the current conducted by the rails does not use total available cross-section which results in higher rail resistance, increased current density, increased ohmic heating and reduced efficiency. It also has considerable influence on the inductance gradient of the Railgun.
Pulsed magnetic field measurements with CMR B-scalar sensors connected in BeScal magnetic sensor system have been performed in static and dynamic Railgun tests.The results have reveled more information than was possible to obtain from theoretical simulations.
The experiments have also shown, that CMR technology can be applied in harsh experimental environment and open possibilities to measure Velocity Skin Effect.
Measurement of magnetic field distribution inside and outside induction coil
Although it may seem that magnetic field inside and outside induction coil can be quite precisely calculated, it is not always the case, especially when magnetic field pulses reach 5, 10 and more Tesla. Due to coil material, coil heating, foreign objects inside or outside the coil, magnetic field values differ from calculated, magnetic field changes direction.
In such cases CMR B-scalar sensors are superior to traditional magnetic field measurement tools like search coil or Hall sensor.
B-scalar sensors are placed in several locations and, when connected to BeScal magnetic sensor system, measure magnetic pulses simultaneously. Use of special non-magnetic sensor holder helps to scan volume inside and outside coil to make pulsed magnetic field mapping in space an time.
This section lists several examples of how BeScal magnetic field measurement sensor system and CMR B-scalar magnetic field sensors can be used for Pulsed high magnetic field measurement, recording and what information can be obtained from these measurements.