Magnetostatic Surface Field Measurement Facility

This note presents the analysis, design, and performance characteristics of an rf Helmholtz coil facility. The facility was developed to measure the magnetic response of models up to two feet in size. Test measurements were made on metallic spheres and cylinders, and on a model F-106 aircraft over a 1-25 MHz frequency range corresponding to 20-520 kHz full scale. A large portion of the note is devoted to the relevant theoretical studies that include studies of the magnetostatic response of . canonical shapes, both perfectly and imperfectly conducting. — ..,,.,, . . RWslm?%! ~wPREFACE The authors wish to thank the many people who contributed to this program. Messrs. Joe Ferris and Jim Morgan constructed the Aluminum Facility. The students who participated were Peter Bower, who constructed the Plywood Facility, and Bruce Dykaar, who analyzed and tested the coil and driver circuits. Jonathan Go (with other help) performed the field measurements and processed the data for facility evaluations and Tim Peters made the measurements on the F-106 model aircraft. Special appreciation goes to Dr. Carl Baum of AFWL, who provided many of the ideas that went into the design of the facility. Thanks also go to Wanita Rasey, Dorothea Merrill, and Jan Fisk for typing the report. .