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 mec...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.展开更多
The Neutralized Drift Compression Experiment-II(NDCX-II)is an induction linac that generates intense pulses of 1.2 MeV helium ions for heating matter to extreme conditions.Here,we present recent results on optimizing ...The Neutralized Drift Compression Experiment-II(NDCX-II)is an induction linac that generates intense pulses of 1.2 MeV helium ions for heating matter to extreme conditions.Here,we present recent results on optimizing beam transport.The NDCX-II beamline includes a 1-m-long drift section downstream of the last transport solenoid,which is filled with charge-neutralizing plasma that enables rapid longitudinal compression of an intense ion beam against space-charge forces.The transport section on NDCX-II consists of 28 solenoids.Finding optimal field settings for a group of solenoids requires knowledge of the envelope parameters of the beam.Imaging the beam on the scintillator gives the radius of the beam,but the envelope angle is not measured directly.We demonstrate how the parameters of the beam envelope(radius,envelop angle,and emittance)can be reconstructed from a series of images taken by varying the B-field strengths of a solenoid upstream of the scintillator.We use this technique to evaluate emittance at several points in the NDCX-II beamline and for optimizing the trajectory of the beam at the entry of the plasma-filled drift section.展开更多
An elliptical Gaussian wave formalism model of a charged-particle beam is proposed by analogy with an elliptical Gaussian light beam. In the paraxial approximation, the charged-particle beam can be described as a whol...An elliptical Gaussian wave formalism model of a charged-particle beam is proposed by analogy with an elliptical Gaussian light beam. In the paraxial approximation, the charged-particle beam can be described as a whole by a complex radius of curvature in the real space domains. Therefore, the propagation and transform of charged-particle beam passing through a first-order optical system is represented by the ABCD-like law. As an example of the application of this model, the relation between the beam waist and the minimum beam spot at a fixed target is discussed. The result, well matches that from conventional phase space model, and proves that the Gaussian wave formalism model is highly effective and reasonable.展开更多
本文概述了基于粒子加速器的核物理研究主要的前沿方向和重要科学问题,分析了用于核物理研究的粒子加速器大科学装置发展现状和未来发展态势.国家"十二五"重大科技基础设施"强流重离子加速器装置"(High Intensity h...本文概述了基于粒子加速器的核物理研究主要的前沿方向和重要科学问题,分析了用于核物理研究的粒子加速器大科学装置发展现状和未来发展态势.国家"十二五"重大科技基础设施"强流重离子加速器装置"(High Intensity heavy-ion Accelerator Facility,HIAF)和"加速器驱动的嬗变研究装置"(China Initiative Accelerator Driven System,CiADS)正在广东惠州建设.以HIAF和CiADS为基础,本文提出建设用于核物理及其交叉前沿研究的大型带电粒子加速器集群装置——高亮度电子-离子研究装置(Bright Electron and Ion Research Facility,BEIF).依托BEIF装置拟开展的核物理前沿研究方向包括原子核结构、核天体物理、核子结构、夸克物质相结构,以及基础物理若干重要前沿与核物理的交叉,如高离化态原子物理、重离子驱动的高能量密度物理等.BEIF是由多台超导直线加速器、同步加速器、储存环、反应堆和各类大型实验探测器及实验终端等组成的大科学装置集群.BEIF计划分三期进行建设,建成后的装置将极大地推动我国的核物理和核科学技术研究能力的提升.展开更多
基金Supported by the National Natural Science Foundation of China under Grant Nos 10247005 and 70071047.
文摘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.
基金This work is supported by the Office of Science of the US DOE under contracts DE-AC0205CH11231,DE-AC52-07NA27344,and DE-AC02-09CH11466.
文摘The Neutralized Drift Compression Experiment-II(NDCX-II)is an induction linac that generates intense pulses of 1.2 MeV helium ions for heating matter to extreme conditions.Here,we present recent results on optimizing beam transport.The NDCX-II beamline includes a 1-m-long drift section downstream of the last transport solenoid,which is filled with charge-neutralizing plasma that enables rapid longitudinal compression of an intense ion beam against space-charge forces.The transport section on NDCX-II consists of 28 solenoids.Finding optimal field settings for a group of solenoids requires knowledge of the envelope parameters of the beam.Imaging the beam on the scintillator gives the radius of the beam,but the envelope angle is not measured directly.We demonstrate how the parameters of the beam envelope(radius,envelop angle,and emittance)can be reconstructed from a series of images taken by varying the B-field strengths of a solenoid upstream of the scintillator.We use this technique to evaluate emittance at several points in the NDCX-II beamline and for optimizing the trajectory of the beam at the entry of the plasma-filled drift section.
文摘An elliptical Gaussian wave formalism model of a charged-particle beam is proposed by analogy with an elliptical Gaussian light beam. In the paraxial approximation, the charged-particle beam can be described as a whole by a complex radius of curvature in the real space domains. Therefore, the propagation and transform of charged-particle beam passing through a first-order optical system is represented by the ABCD-like law. As an example of the application of this model, the relation between the beam waist and the minimum beam spot at a fixed target is discussed. The result, well matches that from conventional phase space model, and proves that the Gaussian wave formalism model is highly effective and reasonable.
文摘本文概述了基于粒子加速器的核物理研究主要的前沿方向和重要科学问题,分析了用于核物理研究的粒子加速器大科学装置发展现状和未来发展态势.国家"十二五"重大科技基础设施"强流重离子加速器装置"(High Intensity heavy-ion Accelerator Facility,HIAF)和"加速器驱动的嬗变研究装置"(China Initiative Accelerator Driven System,CiADS)正在广东惠州建设.以HIAF和CiADS为基础,本文提出建设用于核物理及其交叉前沿研究的大型带电粒子加速器集群装置——高亮度电子-离子研究装置(Bright Electron and Ion Research Facility,BEIF).依托BEIF装置拟开展的核物理前沿研究方向包括原子核结构、核天体物理、核子结构、夸克物质相结构,以及基础物理若干重要前沿与核物理的交叉,如高离化态原子物理、重离子驱动的高能量密度物理等.BEIF是由多台超导直线加速器、同步加速器、储存环、反应堆和各类大型实验探测器及实验终端等组成的大科学装置集群.BEIF计划分三期进行建设,建成后的装置将极大地推动我国的核物理和核科学技术研究能力的提升.
