共查询到20条相似文献,搜索用时 671 毫秒
1.
The Kapchinsky-Vladimirsky beam through an alternating-gradient quadrupole magnetic field is studied using the particle-core model. The beam halo-chaos is found, and the soliton controller is proposed based on the mechanism of halo formation and strategy of controlling halo-chaos. We perform a multiparticle simulation to control the halo by soliton controller, and find that the halo-chaos and its regeneration can be eliminated. It is shown that our control method is effective. 相似文献
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In this paper, the parametric adaptive method for controlling the beam halo-chaos in the periodic focusing channels of high-current proton linacs is presented. The study of proton beam halo-chaos based on controlled beam envelope equation and the results of particles-in-cell simulations for macro-particle beam show that the proton beam chaotic envelope as well as the beam rsm radius can be controlled to the beam matched radius using this method.For the Kapchinskij-Vladimirskij (K- V) distribution of initial proton beam, all statistical physical, quantities of the beam halo-chaos are largely reduced. This control method has an advantage of the control halo-chaos since the exterior magnetic field as controlled parameter can be rather easily adjusted in the periodical magnetic focusing channels for the experiment. 相似文献
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GAOYuan LUOXiao-Shu FANGJin-Qing WENGJia-Qiang 《理论物理通讯》2004,42(1):64-68
In this paper, the parametric adaptive method for controlling the beam halo-chaos in the periodic focusing channels of high-current proton linacs is presented. The study of proton beam halo-chaos based on controlled beam envelope equation and the results of particles-in-ceU simulations for macro-particle beam show that the proton beam chaotic envelope as well as the beam rsm radius can be controlled to the beam matched radius using this method. For the Kapchinskij-Vladimirskij (K-V) distribution of initial proton beam, all statistical physical, quantities of the beam halo-chaos are largely reduced. This control method has an advantage of the control halo-chaos since the exterior magnetic field as controlled parameter can be rather easily adjusted in the periodical magnetic focusing channels for the experiment. 相似文献
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This paper studies the Kapchinsky-Vladimirsky (K-V) beam through a triangle periodic-focusing magnetic field by using the particle-core model. The beam halo-chaos is found, and an idea of Gauss function controller is proposed based on the strategy of controlling the halo-chaos. It performs multiparticle simulation to control the halo by using the Gauss function control method. The numerical results show that the halo-chaos and its regeneration can be eliminated effectively, and that the radial particle density is uniform at the centre of the beam as long as the control method and appropriate parameter are chosen. 相似文献
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Control of beam halo-chaos has been a very challenging subject for research in recent years, in which some nonlinear feedback methods have been developed for suppression of beam halo-chaos in high-current proton linear accelerators. However, stability analysis of such successful nonlinear feedback control methods has not yet been rigorously carried out, which remains an important open topic in the field. In this letter, we present a rigorous mathematical analysis of several nonlinear feedback control methods that are applied to control beam halo-chaos with great success on simulations. 相似文献
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The K-V beam through an axisymmetric uniform-focusing channel is studied
using the particle--core model. The beam halo-chaos is found, and a sample
function controller is proposed based on mechanism of halo formation and
strategy of controlling halo-chaos. We perform multiparticle simulation to
control the halo by using the sample function controller. The numerical
results show that our control method is effective. We also find that the radial
ion density changes when the ion beam is in the channel: not only can the
halo-chaos and its regeneration be eliminated by using the sample
function control method, but also the density uniformity can be found at the
beam's centre as long as an appropriate control method is chosen. 相似文献
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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. 相似文献
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Controlling Beam Halo-Chaos via Time-Delayed Feedback 总被引:1,自引:0,他引:1
The study of controlling high-current proton beam halo-chaos
has become a key concerned issue for many important applications.
In this paper, time-delayed feedback control method is proposed
for beam halo-chaos. Particle in cell simulation results show that
the method is very effective and has some advantages for high-current
beam experiments and engineering. 相似文献
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研究了周期性聚焦磁场通道中,束晕-混沌的外部磁场滑模变结构控制方法。通过选择适当的滑模函数,根据李雅普洛夫稳定性条件,推导出外部磁场的滑模变结构控制器。模拟结果表明,在控制条件下,混沌变化的束包络半径能被控制到匹配半径。将该方法应用在多粒子模型中,实施每隔一个磁场周期就调节一次磁场幅度的控制策略,可实现对初始分布为K-V分布离子束的束晕-混沌的有效控制,束平均发射度降低了80%左右,束晕强度因子变为0,束流质量得到了很好的改善,消除了束晕及其再生现象。由于外部磁场是可测和可调的物理量,控制器简单且利于实现,研究结果可为强流离子加速器中周期性聚焦磁场的设计与试验提供参考。 相似文献
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Control of Halo-Chaos in Beam Transport Network via Neural Network Adaptation with Time-Delayed Feedback 总被引:1,自引:0,他引:1
Subject of the halo-chaos control in beam transport networks (channels) has
become a key concerned issue for many important applications of high-current
proton beam since 1990'. In this paper, the magnetic field adaptive control
based on the neural network with time-delayed feedback is proposed for
suppressing beam halo-chaos in the beam transport network with periodic
focusing channels. The envelope radius of high-current proton beam is
controlled to reach the matched beam radius by suitably selecting the
control structure and parameter of the neural network, adjusting the
delayed-time and control coefficient of the neural network. 相似文献
14.
LIU Qiang FANG Jin-Qing LI Yong 《理论物理通讯》2007,47(4):752-758
The synchronous conditions of two kinds of the small-world (SW) network are studied. The small world topology can affect on dynamical behaviors of the beam transport network (BTN) largely, if the BTN is constructed with the SW topology, the global linear coupling and special linear feedback can realize the synchronization control of beam halo-chaos as well as periodic state in the BTN with the SW topology, respectively. This important result can provide an effective way for the experimental study and the engineering design of the BTN in the high-current accelerator driven radioactive clean nuclear power systems, and may have potential use in prospective applications for halo-chaos secure communication. 相似文献
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在束晕-混沌的小波函数控制已实现的基础上,给出了一种形式更为简单的小波函数控制器,并研究了束晕混沌的多周期间隔反馈控制方法.以控制初始条件遵从Kapchinshij-Vladimirskij分布的离子束为例进行模拟,结果表明,通过适当选择间隔的周期数和小波控制器的控制参数,仍能很有效地对束晕混沌进行控制,并能达到消除束晕及其再生现象的理想结果.研究结果可望为实用强流加速器的研制提供有价值的参考
关键词:
小波函数控制器
多周期间隔
束晕-混沌
强流离子束 相似文献
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周期聚焦磁场中束晕-混沌的简单函数控制 总被引:1,自引:0,他引:1
本文采用粒子-束核模型,基于束晕-混沌的非线性控制策略,对周期性聚焦磁场中满足K—V分布的离子束进行模拟研究,提出了控制其束晕-混沌的简单函数控制器,并给出具体的实施方案.数值模拟研究表明,运用这种方法可以消除束晕及其再生现象,达到对束晕-混沌的有效控制. 相似文献
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A backstepping control method is proposed for controlling beam halo-chaos in the periodic focusing channels (PFCs) of high-current ion accelerator. The analysis and numerical results show that the method, via adjusting an exterior magnetic field, is effective to control beam halo chaos with five types of initial distribution ion beams, all statistical quantities of the beam halo-chaos are largely reduced, and the uniformity of ion beam is improved. This control method has an important value of application, for the exterior magnetic field can be easily adjusted in the periodical magnetic focusing channels in experiment. 相似文献
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In our consideration, a comparison between four different types of controllers for suppression the vibrations of the cantilever beam excited by an external force is carried out. Those four types are the linear velocity feedback control, the cubic velocity feedback control, the non-linear saturation controller (NSC) and the positive position feedback (PPF) controller. The suitable type is the PPF controller for suppression the vibrations of the cantilever beam. The approximate solution obtained up to the first approximation by using the multiple scale method. The PPF controller effectiveness is studied on the system. We used frequency-response equations to investigate the stability of a cantilever beam. We notified that, there is a good agreement between the analytical solution and the numerical solution. 相似文献