Abstract

This paper examines the question of where in the railgun accelerator circuit is the seat of the recoil force. It is explained that conventional electromagnetic field theory and the older Ampere electrodynamics disagree on this point. The former places the recoil force in the remote gun breach while the latter claims it resides in the railheads close to the projectile. An experiment is described which tends to confirm the Ampere prediction. The second part of the paper deals with the force distribution along the projectile branch of the accelerator. Finite current‐element analysis has been employed to show that both theories give approximately the same acceleration force distribution and that the total acceleration force furnished by them agrees well with an experimental check. However, according to the Ampere law, the projectile branch of the circuit should also be subject to strut compression and not only to transverse acceleration. This aspect of the Ampere electrodynamics still awaits experimental confirmation.