EFFECT OF AN ENSEMBLE OF EXPLOSIONS ON THE GALACTIC DYNAMO .1. GENERAL FORMULATION

In this paper, we derive a general analytical expression for the electromotive force produced by a field of explosions in the Galactic disk. We consider spherically symmetric and axisymmetric explosions successively. We first calculate the velocity and magnetic fields associated with one explosion and average their cross-product over a spatial distribution of explosions. We then provide simple expressions for the magnetic flux escape velocity and for the so-called alpha-parameter.