Due to the lack of mature design program for the tubular permanent magnet linear wave generator (TPMLWG) and poor sinusoidal characteristics of the air gap flux density for the traditional surface-mounted TPMLWG, a design method and a new secondary structure of TPMLWG are proposed. An equivalent mathematical model of TPMLWG is established to adopt the transformation relationship between the lin...

This paper deals with the use of a magnetic levitation system as a part of a multi-stage seismic attenuator for gravitational wave interferometric antennas. The proposed configuration uses permanent magnets in attraction to balance the suspended weight, plus a closed loop position control to obtain a stable levitation. The system is analyzed using a MATLAB simulation code to compute the forces ...

Standard Magnetic Resonance magnets produce a single homogeneous field volume, where the analysis is performed. Nonetheless, several modern applications could benefit from the generation of multiple homogeneous field volumes along the axis and inside the bore of the magnet. In this communication, we propose a straightforward method using a combination of ring structures of permanent magnets in ...

We study different configurations of permanent magnets and ferromagnetic circuit, in order to optimize the magnetic field for the so-called “magnetic tweezers” technique, for studing mechanical properties of DNA molecules. The magnetic field is used to pull and twist a micron-sized superparamagnetic bead, tethered to a microscope slide surface by a DNA molecule. The force applied to the bead mu...

The Theme: Due to environmental and energy concerns, electric vehicles (EVs) and hybrid electric vehicles (HEVs) are gaining increased attention. At the heart of the drive system of these vehicles is the electric machine and drive. For these applications, high power density, high torque density, wide speed range, and efficiency are of primary importance. To meet these demands, interior permanen...

observed by Meiklejohn and Bean1 (cobalt particles in shells of antiferromagnetic cobalt oxide); both are inhomogeneous and the coexistence of a ferromagnetic and an antiferromagnetic phase gives rise to large exchange bias. This demonstration of tuning the composition of certain Heusler alloys to attain exceptionally high exchange bias fields indicates a route for designing rare-earth-free har...

Title of Document: DEV DEVELOPMENT AND TEST OF A PERMANENT MAGNET HELICON THRUSTER Michael Frank DeMaio, Jr. M.S. 2010 Directed By: Assistant Professor Raymond Sedwick, Department of Aerospace Engineering This thesis describes the development of a test facility equipped with Langmuir probe and Retarding Potential Analyzer diagnostics for helicon thruster research. A helicon thruster using perma...

Superconductors with persistent zero-resistance currents serve as permanent magnets for high-field applications requiring a strong and stable magnetic field, such as magnetic resonance imaging (MRI). The recent global helium shortage has quickened research into high-temperature superconductors (HTSs)—materials that can be used without conventional liquid-helium cooling to 4.2 K. Herein, we demo...

In a surface-mounted sintered NdFeB permanent-magnet generator, the magnets are usually thin (typically 4 mm), and hence the armature reaction, due to the time harmonics in the stator currents, is high. NdFeB magnets are conducting (resistivity typically 1.6 μΩm) and experience eddy-current losses. Therefore, the combined eddy-current losses in the NdFeB magnets and a solid iron rotor may becom...