Magnetic Circuit Design

[Hopkins]

I am a Mechanical Engineer trying to learn some basics of magnetic circuit design for a project at work. Specifically, I need to design and optimize an electromagnetic coil for a magnetorheological (MR) fluid damper. Do you know of any good practical design books or tools for this task?

We are also considering the use of two coaxial coils: one with many turns for low-bandwidth magnetic field bias and the other with fewer turns for high bandwidth control about the bias. Is this a good idea, or will the transformer effects make it impossible to control?

Thanks in advance,
Brian Hopkins