共查询到14条相似文献,搜索用时 187 毫秒
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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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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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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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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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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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The KV beam through an axisymmetric periodic-focusing magnetic field is studied using the particle-core model. A new variable of the self-field-intensity of particle beam is selected, and an idea of self-field feedback controller is proposed based on the variable for controlling the halo-chaos. We perform multiparticle simulation to control the halo by using the self-field feedback controller. The numerical results show that the halo-chaos and its regeneration can be eliminated effectively, and that the density uniformity can be found at the centre of beam as long as an appropriate control method is chosen. The control method may be operated in the experiment, because field intensity measurement is easy. 相似文献