Abstract
An experiment currently being developed on the Alcator-C magnetic fusion device uses a set of poloidal B-field pick-up coils and unique analyzing circuits to continuously yield the amplitudes, frequencies, and rotational directions of the m = 1,2,3,4, and 5 resistive MHD tearing modes. The experiment is being used to study the growth and coupling of tearing modes of different helicities due to density, temperature, and current profiles.