Search results for "Halbach array"
showing 3 items of 3 documents
High homogeneity permanent magnet for diamond magnetometry
2020
Abstract Halbach magnets are a source of homogeneous magnetic field in an enclosed volume while keeping stray fields at a minimum. Here, we present the design, construction, and characterization for a stack of two Halbach rings with 10 cm inner diameter providing a homogeneous ( 100 ppm over 1.0 × 1.0 × 0.5 cm 3 ) magnetic field of around 105 mT, which will be used for a diamond based microwave-free widefield imaging setup. The final characterization is performed with a novel fiberized diamond-based sensor on a 3D translation stage documenting the high homogeneity of the constructed Halbach array and its suitability for the proposed use.
Arrays of Rotating Permanent Magnet Dipoles for Stirring and Pumping of Liquid Metals
2015
AbstractMultiple configurations of synchronously rotating permanent magnet cylinders magnetized across the axes are proposed for liquid metal stirring for homogenization as well as for pumping. Universal analytical model is used for an initial parameter analysis. Then experimental setups were built to perform physical modelling of the industrial applications, e.g. large-scale metallurgical furnaces. Velocity distribution in the liquid metal was measured using different methods: the Ultrasound Doppler anemometry and the potential difference probes. The study shows that the cylindrical permanent magnet setups can achieve up to 10 times higher energy efficiency compared to AC inductors and hav…
A concept for a magnetic particle imaging scanner with Halbach arrays
2020
Magnetic particle imaging (MPI) is a new medical imaging technique visualizing the concentration distribution of superparamagnetic nanoparticles used as tracer material. MPI is not yet in clinical routine, since one of the challenges is the upscaling of scanners. Typically, the magnetic fields of MPI scanners are generated electromagnetically, resulting in an immense power consumption but providing high flexibility in terms of adjusting the field strengths and very fast image acquisition rates. Permanent magnets provide high flux densities and do not need any power supply. However, the flux density is not adjustable, and a mechanical movement is slow compared to electromagnetically varying …