Ring Around the Magnet
Janis Niedra of the Thermal Energy Conversion Branch at NASA Glenn is using a Helmholtz coil to measure the approximate remanence of a magnet segment. Remanence is the magnetic flux that remains in a magnet after an external magnetic field has been removed.
The magnet segment being measured is similar to those used in the linear alternator of the Advanced Stirling Convertor (ASC), designed and built by Sunpower, Inc.
The magnet, not shown, is positioned in the slot cut along the top of the aluminum block at the center of the coil in the region of uniform sensitivity. The ASC is the type of free-piston Stirling convertor used in the Advanced Stirling Radioisotope Generator (ASRG) currently being developed by Lockheed-Martin for the Department of Energy and NASA.
Image Credit: NASA
Marvin G. Smith (Wyle Information Systems, LLC)