Bubble forces in cylindrical magnetic domain systems

The force exerted on a bubble by a current and by other bubbles is calculated. We examine the force on a bubble from straight current-carrying conductors of finite width and length and from conductors that are bent. We find that if the conductor's width is less than or equal to a bubble radius, the force on a bubble from a conductor pattern may be approximated by zero-width connected current-carrying segments. The mutal repulsive force between two bubbles is also determined. An important feature of this calculation is that the mutual decrease in bubble radii that occurs as two bubbles approach one another is taken into account. Bubble-bubble force curves as a function of material thickness are given for bubble spacings corresponding to typical current and field access circuits.