Abstract: A method of which the stored inductive energy is provided for fuze in the process of information setting before a projectile lauch was proposed in order to solve the problem of small room for designing a small-calibre electronic fuze. This method, which can save the space of extra fuze power, provides a new way to design fuze power. Therefore, a mathematical model of electromagnetic induction in the bore was set up. The characteristics of magnetic field penetrating through the metal gun barrel made of nonferromagnetic material were analyzed. The analyses results show that the magnetic field intensity can be 80% of the source after penetration only if the frequency of external electromagnetic excitation should be less than 5 kHz. With the increase in the frequency of source magnetic field, the magnetic field intensity is exponentially attenuated after penetrateion. The experimental results show that the inductive energy storage fuze prototype designed according to the above-mentioned theory meets the technical requirements of small calibre fuze. And the analyses conclusion of magnetic field penetration characteristics is helpful to design the inductive energy storage fuze in bore.

Key words: electromagnetics, fuze, inductive setting, induction energy storage, electromagnetic field