Affiliations: [a] National Key Laboratory of Transient Physics, Nanjing University of Science & Technology, Nanjing, Jiangsu, China | [b] School of Mechanical Engineering, Nanjing University of Science & Technology, Nanjing, Jiangsu, China
Correspondence:
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Corresponding author: Na Shen, National Key Laboratory of Transient Physics, Nanjing University of Science & Technology, Nanjing 210094, Jiangsu, China. Tel./Fax: +86 025 84315646; E-mail:snbox@njust.edu.cn
Abstract: During a launch with an electromagnetic railgun its
payload is subjected to both extreme mechanical stresses and strong
electromagnetic interference. Therefore, the design of electronic parts of
the payload, such as a fuse of an ammunition, poses technical challenges.
This paper focuses on the magnetic shielding technique of intelligent
ammunition fuses. After considering the magnetic field distribution
including the velocity skin effect, a surface model of a railgun was built.
Double exponential pulses similar to capacitor discharges were used as power
supply. Spatial distribution regularities and frequency spectrum
characteristics of pulsed strong magnetic field in the chamber of the rail
gun were analyzed. Based on these results a simulation and an experimental
analysis of the shielding effectiveness of a strong magnetic field
environment designed for a railgun payload was conducted. The shielding
effectiveness of different shield materials, located at different distances
in front of the armature and at different positions inside the shield. The
results indicated the feasibility of effectively shielding the strong
magnetic field in the chamber of a railgun during the launch. These findings
can serve as a reference for future railgun intelligent ammunition shielding
designs.
Keywords: The electronic-magnetic rail gun, ammunition fuse, magnetic shielding technique
