Active magnetic regenerative cooling with smaller magnets

Smaller magnets for smarter minds?

Human brain stimulation for therapeutic purposes has many short- and long-term limitations. The possibility of implanting magnetic, rather than electrical, stimulation devices would present a possible solution to some of the problems. The development of a new microscopic magnetic stimulation device provides a glimpse of the realisation.

Designing magnets with prescribed magnetic fields

We present a novel design method capable of finding the magnetization densities that generate prescribed magnetic fields. The method is based on the solution to a simple variational inequality and the resulting designs have simple piecewiseconstant magnetization densities. By this method we obtain new designs of magnets that generate commonly used magnetic fields: uniform magnetic fields, self-...

Nuclear Magnetic Resonance With No Magnets

Spectroscopy with conventional nuclear magnetic resonance (NMR) requires large, expensive, superconducting magnets cooled by liquid helium, like the one in the background. The Pines and Budker groups have demonstrated NMR spectroscopy with a device only a few centimeters high, using no magnets at all (foreground). A chemical sample in the test tube (green) is polarized by introducing hydrogen g...

MAGNETIC VISCOSITY IN NdFeB MAGNETS

The relaxation of the magnetization is calculated for isotropic and anisotropic magnets. For NdFeB magnets, the dependence of Sv on texture, above room temperature, is roughly consistent with the model, while the NdDyFeB magnets show no dependence upon texture.

Magnetic Ordering in Layered Magnets