The Department of Energy sponsors a laboratory that is currently working on magnetic fusion devices based on what principle?
National Spherical Torus Experiment The National Spherical Torus Experiment (NSTX) is an innovative magnetic fusion device based on the "spherical tokamak" concept. It was constructed by the Princeton Plasma Physics Laboratory (PPPL) in collaboration with the Oak Ridge National Laboratory, Columbia University, and the University of Washington at Seattle.
Evans balance An Evans balance, also known as a Johnson-Matthey balance(after the most prolific producer of the Evans balance) is a device for measuring magnetic susceptibility. Magnetic susceptibility is related to the force experienced by a substance in a magnetic field. Various practical devices are available for the measurement of susceptibility, which differ in the shape of the magnetic field and the way the force is measured.