Beam halo-chaos in high-current accelerators has become a key concerned issue because it can cause excessive radioactivity from the accelerators therefore signi cantly limits their applications in industry, medicine, and national defense. Some general engineering methods for chaos control have been developed in recent years, but they generally are unsuccessful for be a mhalo-chaos suppression due to many technical constraints. Beam halo-chaos is essentially a spatiotemporal chaotic motion within a high po wer proton accelerator. In this paper, some e cient nonlinear control methods, including wavelet function feedback control as a special nonlinear control method, are proposed for controlling be a mhalo-chaos under ve kinds of the initial proton beam distributions (i.e., Kapchinsky{Vladimirsky, full Gauss, 3-sigma Gauss, water-bag, and parabola distributions) respectively. Particles-in-cell simulations show that after control of be a mhalo-chaos, the beam halo strength factor is reduced to zero, and other statistical physical quantities of beam halo-chaos are doubly reduced. The methods we developed is very e ective for suppression of proton be a mhalo-chaos in a pe r i od i cfocusing channel of accelerator. Some potential application of the be a mhalo-chaos control in experiments is nally po i n ted out.

Accelerator driven clean nuclear power system (ADS) as an innovative technique in the 21st century is among the most challenge of high-tech fields since it makes nuclear power system safer, cleaner, cheaper, and more reliable. ADS is very necessary option for sustainable development of nuclear energy in the 21st century. However, beam halo-chaos occurred in high-current accelerators of ADS has become a key concerned issue for many important applications of intensity ion beam.To understand the complex of beam halo-chaos, this paper analyzes one of the main physical mechanism for halo-chaos formation, i.e. nonlinear resonance overlapping routes to halo-chaos. Then some efficient nonlinear control methods of beam halo-chaos are presented. The simulation results demonstrate that the control methods we proposed are very effective for beam halo-chaos suppression.