Internal Magnetic Field Measurement of Plasmas Using an Alpha Particle VxB Detector

75337-It is very important to measure the internal magnetic field distribution inside hot plasmas associated with magnetic fusion research; however, a material probe cannot survive the plasma without disturbing the process. This project will develop a magnetic field detector, useful for current and future magnetic fusion research, by employing a radioactive source of MeV alpha particles just outside the plasma. The magnetic VxB deflection of these alpha particles by the magnetic fields inside the plasma will be detected and measured by a large-area alpha particle detector array that is located outside the plasma envelope, but positioned in the path of the deflected alpha particles. In Phase I the Alpha VxB or ¿AVB¿ detector concept will be refined, and the alpha detector array technology that best meets the magnetic field measurement requirements will be identified. In Phase II, the resulting conceptual design from Phase I will be completed, built, evaluated, and delivered for use as a magnetic field diagnostic in the National Spherical Torus Experiment (NSTX). Commercial Applications and Other Benefits as described by the awardee: The primary application for the proposed state-of-the-art improvement in plasma magnetic field diagnosis and related large area charge particle detection arrays is in nuclear fusion research.