Wong Study of Collapse processes in strong electromagnetic (EM) wave interactions with magnetized and unmagnetized plasmas. The program consists of: the search for caviton collapse generated by EM waves at the resonant layer as predicted by recent theoretical treatments; the optical imaging of Langmuir cavitons; the nonlinear generation of radiation bursts by collapsing cavitons; the observation of collapse in high beta plasmas in a unique quasi-steady-state magnetic plasmas. Other areas related to high power EM waves which are proposed for study are: the decay of a strong EM wave into the "2wp instabilities", the nonlinear heating and cooling rates of electrons by EM waves and the production and confinement of very high density plasmas by solely EM fields in the absence of a static magnetic field.