EXCITATION AND STUDY OF SUBCRITICAL WAVES ON A MAGNETIC FLUID SURFACE

We find that subcritical standing waves are excited when a time-period ic field is superposed collinearly on a steady field with normal orien tation to a pool of magnetic fluid. The wavelengths of the disturbance undergo repeated, stepwise reductions as the steady field intensity i s increased. A theory of the onset is derived and comparison is made w ith the data.