Nonlinear Control of Beam Halo-Chaos in Accelerator-Driven Clean Nuclear Power System

Beam halo-chaos in high-current accelerators has become a key concerned issue because it can cause excessive radioactivity from the accelerators therefore significantly 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 beam halo-chaos suppression due to many technical constraints.Beam halo-chaos is essentially a spatiotemporal chaotic motion within a high power proton accelerator.In this paper,some efficient nonlinear control methods,including wavelet function feedback control as a special nonlinear control method,are proposed for controlling beam halo-chaos under five 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 beam halo-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 effective for suppression of proton beam halo-chaos in a periodic focusing channel of accelerator.Some potential application of the beam halo-chaos control in experiments is finally pointed out.

束晕-混沌的复杂性理论与控制方法及其应用前景

本文系统论述涉及强流加速器等强流离子束装置中产生的束晕 混沌的复杂性理论与控制方法及其应用前景。强流离子束在核材料生产与增殖、洁净核能、放射性废物嬗变、放射性药物生产、重离子聚变、高能物理、核科学与工程、国防与民用工业和医疗等许多方面都有极其重要的应用潜力和诱人的发展前景。尤其是,近年来强流加速器驱动的放射性洁净核能系统是国内外关注的热门课题,因为它比常规核电更安全、更干净、更便宜。但是,强流离子束形成的束晕 混沌的复杂性现象已引起了国内外广泛关注,需要加以抑制、控制和消除这类现象,解决这一难题已经成为强流离子束应用中的关键问题之一。目前不仅必须深入研究这类束晕 混沌的复杂特性及其产生的物理机制,而且需要研究如何实现对束晕 混沌的有效控制,并寻求和发展其新理论、新方法和新技术。这就向强流离子束物理和非线性-复杂性科学及其技术提出了一系列极富挑战性的新课题。本文结合国内外的研究概况,根据我们多年来的研究成果,特别是我们首创性地提出了一些束晕 混沌的有效控制方法,它们包括:非线性反馈控制 法,小波反馈控制法,变结构控制法,延迟反馈控制法,参数自适应控制法等,进行重点的介绍。