Parametric resonances and stochastic layer induced by a phase modulation

The Hamiltonian system with phase modulation in a higher harmonic RF cavity is experimentally studied on the IUCF cooler ring. The Poincare maps in the resonant rotating frame are obtained from experimental data and compared with numerical tracking. The formation of the stochastic layer due to the overlap of parametric resonances is discussed. The dependence of the stochastic layer on the voltage of the higher harmonic RF cavity, amplitude and frequency of the phase modulation is studied.