Plasma fusion research experiments require magnetic field measurements over a wide range of bandwidth and sensitivity. However, existing pickup coil sensors are limited in bandwidth, require time integration, and perturb the experiment when used as inserted diagnostics. Novel sensors that can be used for edge or insertion measurements of magnetic fields ranging from 0.01 to 100 Gauss over a bandwidth from DC to 100 MHz are needed. This project will develop a non-perturbing, high bandwidth, high sensitivity optical sensor as a next generation magnetic field diagnostic for plasma fusion experiments. The sensors galvanically isolated output signal will not require time integration. The sensor package will be engineered to handle high bake-out and operating temperatures in excess of 250°C. Phase I optimized the design of a novel optical magnetic field sensor for plasma fusion applications. A complete system design was developed including the light source, receiver, optical sensor, and packaging. In Phase II, several sensor designs will be assembled and tested on the Spheromak at Lawrence Livermore National Laboratory. High frequency performance will be determined for other commercial applications.
Commercial Applications and Other Benefits as described by the awardee: The proposed optical sensor design should allow various sensitivity and bandwidth configurations to support magnetic field measurements in plasma research, ranging from low temperature university experiments to larger scale spheromak and tokamak machines. The sensor also should find use in pulsed power and accelerator research; high power antenna mapping; radiographic machines; and non-invasive, non-loading, high-speed current probes for electronic test equipment
