In-Bore Magnetic Field Management
Final rept. Oct 97-Sep 98
ARMY RESEARCH LAB ABERDEEN PROVING GROUND MD
Pagination or Media Count:
The turbinealternator TA in the M734A1 Multi-Option Fuze for Mortar MOFM was identified as a component whose performance was altered by exposure to the in-bore magnetic induction produced by the armature in an electromagnetic railgun. Passive shielding techniques were developed to attenuate the exposure field. A model, based on the experimental results, was used to predict shielding effectiveness. Results were verified by subjecting TAs to the exposure field. No statistically significant changes in TA output were observed for magnetic induction less than 0.06 T. Significant degradation in performance was observed for magnetic induction greater than 0.1 T. Active shielding was also demonstrated. This technique was implemented with coil windings mounted in the bore insulators and powered by an external power supply. The in-bore magnetic induction produced by the armature was canceled down-bore of the armature. The technique provides for mitigation of large magnitude exposure fields where otherwise passive shielding may become unwieldy.
- Electromagnetic Shielding