This award supports Dr. Raul A. Stern of the University of Colorado and Dr. Nathan Rynn of the University of California at Irvine to collaborate with Dr. M.Q. Tran and others of the Center for Research in Plasma Physics of the Ecole Polytechnique Federale, Lausanne, Switzerland in a study of the transition to stochasticity in non-equilibrium plasmas. The program brings together researchers who are carrying out active projects in this area individually, and have already collaborated successfully on this topic. Use will be made of unique, newly-developed experimental facilities, including a 9-meter long plasma column, fully magnetized and super-uniform, which can operate both as a gas-discharge (high Te/Ti) and a quiescent (BaII) plasma, together with the newest laser-induced fluorescence diagnostic technologies. Research will consist of plasma wave excitation on the ionic branches, together with measurements of ion velocity distributions and ion transport, to map out the phase-space history of ions during wave-particle interactions. Results will be coordinated with numerical studies. This collaborative project combines complementary skills and resources and exploits a unique, world class research facility in Lausanne that was specially designed for experimental studies in this field. The topic of intrinsic stochasticity in wave-particle interactions is a rapidly developing subject; it is central to fundamental plasma physics and it has direct applications to studies of plasmas in astronomy and fusion research.