Intense beam production of highly charged heavy ions by the superconducting electron cyclotron resonance ion source SECRAL (invited)

There has been increasing demand to provide higher beam intensity and high enough beam energy for heavy ion accelerator and some other applications, which has driven electron cyclotron resonance (ECR) ion source to produce higher charge state ions with higher beam intensity. One of development trends for highly charged ECR ion source is to build new generation ECR sources by utilization of superconducting magnet technology. SECRAL (superconducting ECR ion source with advanced design in Lanzhou) was successfully built to produce intense beams of highly charged ion for Heavy Ion Research Facility in Lanzhou (HIRFL). The ion source has been optimized to be operated at 28 GHz for its maximum performance. The superconducting magnet confinement configuration of the ion source consists of three axial solenoid coils and six sextupole coils with a cold iron structure as field booster and clamping. An innovative design of SECRAL is that the three axial solenoid coils are located inside of the sextupole bore in order to reduce the interaction forces between the sextupole coils and the solenoid coils. For 28 GHz operation, the magnet assembly can produce peak mirror fields on axis of 3.6 T at injection, 2.2 T at extraction, and a radial sextupole field of 2.0 T at plasma chamber wall. During the commissioning phase at 18 GHz with a stainless steel chamber, tests with various gases and some metals have been conducted with microwave power less than 3.5 kW by two 18 GHz rf generators. It demonstrates the performance is very promising. Some record ion beam intensities have been produced, for instance, 810 e mu A of O7+, 505 e mu A of Xe20+ 306 e mu A of Xe27+, and so on. The effect of the magnetic field configuration on the ion source performance has been studied experimentally. SECRAL has been put into operation to provide highly charged ion beams for HIRFL facility since May 2007.

Production of highly charged ion beams with SECRAL

Superconducting electron cyclotron resonance ion source with advanced design in Lanzhou (SECRAL) is an all-superconducting-magnet electron cyclotron resonance ion source (ECRIS) for the production of intense highly charged ion beams to meet the requirements of the Heavy Ion Research Facility in Lanzhou (HIRFL). To further enhance the performance of SECRAL, an aluminum chamber has been installed inside a 1.5 mm thick Ta liner used for the reduction of x-ray irradiation at the high voltage insulator. With double-frequency (18+14.5 GHz) heating and at maximum total microwave power of 2.0 kW, SECRAL has successfully produced quite a few very highly charged Xe ion beams, such as 10 e mu A of Xe37+, 1 e mu A of Xe43+, and 0.16 e mu A of Ne-like Xe44+. To further explore the capability of the SECRAL in the production of highly charged heavy metal ion beams, a first test run on bismuth has been carried out recently. The main goal is to produce an intense Bi31+ beam for HIRFL accelerator and to have a feel how well the SECRAL can do in the production of very highly charged Bi beams. During the test, though at microwave power less than 3 kW, more than 150 e mu A of Bi31+, 22 e mu A of Bi41+, and 1.5 e mu A of Bi50+ have been produced. All of these results have again demonstrated the great capability of the SECRAL source. This article will present the detailed results and brief discussions to the production of highly charged ion beams with SECRAL.

New development of advanced superconducting electron cyclotron resonance ion source SECRAL (invited)

Superconducting electron cyclotron resonance ion source with advance design in Lanzhou (SECRAL) is an 18-28 GHz fully superconducting electron cyclotron resonance (ECR) ion source dedicated for highly charged heavy ion beam production. SECRAL, with an innovative superconducting magnet structure of solenoid-inside-sextupole and at lower frequency and lower rf power operation, may open a new way for developing compact and reliable high performance superconducting ECR ion source. One of the recent highlights achieved at SECRAL is that some new record beam currents for very high charge states were produced by 18 GHz or 18+14.5 GHz double frequency heating, such as 1 e mu A of Xe-129(43+), 22 e mu A of Bi-209(41+), and 1.5 e mu A of Bi-209(50+). To further enhance the performance of SECRAL, a 24 GHz/7 kW gyrotron microwave generator was installed and SECRAL was tested at 24 GHz. Some promising and exciting results at 24 GHz with new record highly charged ion beam intensities were produced, such as 455 e mu A of Xe-129(27+) and 152 e mu A of Xe-129(30+), although the commissioning time was limited within 3-4 weeks and rf power only 3-4 kW. Bremsstrahlung measurements at 24 GHz show that x-ray is much stronger with higher rf frequency, higher rf power. and higher minimum mirror magnetic field (minimum B). Preliminary emittance measurements indicate that SECRAL emittance at 24 GHz is slightly higher that at 18 GHz. SECRAL has been put into routine operation at 18 GHz for heavy ion research facility in Lanzhou (HIRFL) accelerator complex since May 2007. The total operation beam time from SECRAL for HIRFL accelerator has been more than 2000 h, and Xe-129(27+), Kr-78(19+), Bi-209(31+), and Ni-58(19+) beams were delivered. All of these new developments, the latest results, and long-term operation for the accelerator have again demonstrated that SECRAL is one of the best in the performance of ECR ion source for highly charged heavy ion beam production. Finally the future development of SECRAL will be presented.

Some Superconducting Magnets at IMP

Some superconducting magnets research at IMP (Institute of Modern Physics, CAS, Lanzhou) will be described in this paper. Firstly, a superconducting electron cyclotron resonance ion source (SECRAL) was successfully built to produce intense beams of highly charged heavy ions for Heavy Ion Research Facility in Lanzhou (HIRFL). An innovation design of SECRAL is that the three axial solenoid coils are located inside of a sextupole bore in order to reduce the interaction forces between the sextupole coils and the solenoid coils. For 28 GHz operation, the magnet assembly can produce peak mirror fields on axis of 3.6 T at injection, 2.2 T at extraction, and a radial sextupole field of 2.0 T at plasma chamber wall. Some excellent results of ion beam intensity have been produced and SECRAL has been put into operation to provide highly charged ion beams for HIRFL since May 2007. Secondly, a super-ferric dipole prototype of FAIR Super-FRS is being built by FCG (FAIR China Group) in cooperation with GSI. Its superconducting coils and cryostat is made and tested in the Institute of Plasma Physics (IPP, Hefei), and it more 50 tons laminated yoke was made in IMP. This super-ferric dipole static magnetic field was measured in IMP, it reach to the design requirement, ramping field and other tests will be done in the future. Thirdly, a 3 T superconducting homogenous magnetic field solenoid with a 70 mm warm bore has been developed to calibrate Hall sensor, some testing results is reported. And a penning trap system called LPT (Lanzhou Penning Trap) is now being developed for precise mass measurements.

The Application of Toolkit of Optimization in Designs of Accelerator Magnets

The traditional design of accelerator magnet usually involves many time consuming iterations of the manual analysis process. A software platform to do these iterations automatically is proposed in this paper. In this platform, we use DAKOTA (a open source software developed by Sandia National Laboratories) as the optimizing routine, which provides a variety of optimization methods and algorithms, and OPERA (software from Vector Fields) is selected as the electromagnetic simulating routine. In this paper, two examples of designs of accelerator magnets are used to illustrate how an optimization algorithm is chosen and the platform works.

Magnetic Field Design of the Dipole for Super-FRS at FAIR

The Super-FRS (Super FRagment Separator) is a part of FAIR (Facility for Antiproton and Ion Research), which will be constructed at GSI, Germany by 17 countries. The Super-FRS comprises 24 superferric dipole magnets. The 2D and 3D magnetic field simulations of the prototype magnet are described in this paper. A passive trim slot and four chamfered removable poles are used to satisfy the required field homogeneity which is better than +/-3 x 10(-4) at 1.6 T, 0.8 T and 0.16 T in a wide elliptical useable aperture of 380 mm x 140 mm. Measurement results at various field levels are shown in this paper as well. It can be seen from the comparison of calculation and measurement results that the magnetic designs of the magnet fulfils the requirements.

CSR主环磁场电源控制系统研究

CSR控制系统是一个很庞大的系统，对它的控制是由许多分控制系统组成： 真空系统、电子冷却系统、束流诊断系统，CSR高频系统，数据获取系统等。磁 场电源控制系统是CSR控制系统中很重要的一部分，它是一个任意波形发生系统。 在CSR的分控制系统中，所有依赖波形控制的系统都可以由它来控制。波形的形 状由物理人员根据加速器物理要求计算得出。因为加速器运行的所有过程都为电 源所控制，所以我们的控制系统的直接控制对象就是磁场电源。在整个控制系统 中最重要的就是在控制过程中，控制过程波形的同步和控制过程波形的精度，这 是同步加速器控制系统的关键所在。过程波形的同步由同步时序系统控制，这是 CSR主环成功运行的决定条件。 本文对磁场电源控制系统和时序系统分别进行了论述。对磁场电源控制系统， 主要从系统的结构，I/O部件的硬件设计，I/O部件的软件设计这几个方面进行 论述,其中，I/O部件由I/O控制器和DSP处理器组成；对时序系统，论述了设计 原理和具体实现；最后给出了实验平台测试和现场测试的结果。 本文的创新点主要有，在加速器控制领域：（1）采用ARM+DSP的控制方式； （2）同步时序系统的末端定时原理； 从测试结果来看，我们的控制系统不管从结构设计，还是从软硬件设计上都 达到了设计的要求

Bump磁铁电源控制器的设计

HIRFL—CSR（兰州重离子冷却储存环）是国家 “九五”重大科学工程之一。在磁铁电源的控制系统中需要电源控制器及时准确的提供基准的电压波形，并对输出的波形进行回读监测，以保证加速器正常工作。 论文介绍了电源系统的要求和特点，并根据设计要求给出了设计思想和系统框图，本控制系统主芯片采用TI公司的TMS320C6713芯片，并给出了DSP系统设计的一般流程。文中详细介绍了TMS320C6713芯片的结构和性能指标，以及其外围电路和存储器的扩展情况，指出了在高速电路板设计时应注意的问题。 设计中使用可编程逻辑器件，使设计可灵活配置，电路板设计在有BGA封装器件情况下实现四层板手工布线。 论文完成的Bump磁铁电源控制器的硬件电路设计，为以后的软件编写和测试搭建了坚实的平台

CSR中磁铁线圈温度测量系统的研制

本论文主要讲述了一种服务于CSR磁铁保护的多路（64路）磁铁线圈温度测量系统。根据CSR工程的要求，该温度测量系统能对磁铁线圈中的数百个点进行测温，并达到±1℃的测温精度。文中详细阐述了该系统软硬件的研究、设计和实现。该测量系统中，主控芯片采用了美国德州仪器公司的16位低功耗单片机MSP430F149，论文中详细介绍了该单片机的结构特性、功能和基于该单片机的硬件组成和软件设计。硬件主要包括前端信号处理电路、A/D转换电路、VCO电路、液晶显示电路、数字键盘电路、以及为实现远程实时监测而采用的RS-485串行通信电路。在软件设计方面，利用IAR公司的C430 为开发工具 ，采取模块化设计方法，用C语言编制了温度测量系统的主控程序以及液晶驱动、键盘驱动、串行通信等程序模块，并配合硬件系统进行了多次调试（论文软件设计中给出了部分源程序清单）。论文最后讨论了适用于CSR现场工作环境的软硬件抗干扰措施及其实现。通过试验，该温度测量系统表现良好，满足设计要求。其特点是低成本、低功耗、可靠性高、并可根据不同需要应用于多种工程检测系统中

同步加速器磁场电源控制系统的优化研究

CSR控制系统是一个基于网络的分布式控制系统，它是由许多分控制系统组成。磁场电源控制系统是CSR控制系统中很重要的一部分，它是一个波形发生、数据采集系统。所有依赖波形控制的系统都可以由它来控制。波形的参数由物理学家根据实验需要计算得出。因为加速器所有的运行状态都被电源所控制，所以控制系统的直接控制对象就是磁场电源。在整个控制系统中最重要的就是控制波形的同步和波形的精度，这是同步加速器控制系统的关键所在。波形的同步由同步时序系统控制，这是CSR成功运行的决定条件。数据的采集、电源状态的监测由数据采集模块CPLD负责完成，与前端ARM控制器结合，形成数据的上行通道。采集到的数据均存放在中央控制室的数据库中，以供参考、后期分析及应用。论文论述了对CSR磁场电源控制系统、时序系统和软件系统的设计实现及优化改进

基于新技术的超导电源及失超保护装置研究与设计

超导磁铁以其能实现极高的磁场强度和较低的能量损耗的优势，正在迅速成为现代加速器系统中普遍采用的一项技术。为超导磁体提供励磁的超导电源也就成为了必需研究的课题。此外，与之相似的低压大电流电源也大量的应用于加速器系统中，服务于核物理研究工作。针对这类电源在加速器中的应用，本课题的主要挑战在于如何实现一种高效率和低纹波输出特性的电源。为此，本论文的作者采用了一种完全不同的拓扑结构“多路多相同步整流BUCK变换器”，来达到高效率和低纹波的目标。并尝试使用数字技术来实现控制单元。本论文首先详细介绍了“多路多相同步整流BUCK变换器”的拓扑，通过计算和推导介绍了这种拓扑是如何提高效率和减少纹波电流输出的。然后介绍了这种拓扑结构所必需解决的均流问题、其产生原因和解决办法：一种几乎无损的单路电流的测量方法，以及这种测量方法的原理和实现方法。之后介绍了整个电源的参数计算和PCB板设计的一些细节。最后详细介绍了用MCU实现的控制器的设计细节。作为超导电源必配的失超保护装置，它担负着在失超故障状态，将超导磁体内存储的能量在尽量短的时间内消耗在外部负载上，以用于实现保护超导磁体的功能。因此超导磁铁失超保护装置 的设计原则是：可靠性和经济性。本论文最后一部分详细介绍了按照这个目标设计的超导磁铁失超保护装置及其设计细节

SUPER-FRS/CR超导磁体力学性能分析

中国签订了为德国FAIR国际大科学工程加工SUPER-FRS/CR超导二极磁铁样机的合作备忘录。该超导二极磁铁属于常温铁芯、低温线圈的超导磁铁，该磁铁的磁场强度0.15～1.6T，偏转角度15°，偏转半径8125mm，磁场精度要求±1×10-4，磁铁总重量约50吨。磁铁铁芯采用0.5mm的硅钢片叠压成型，由中科院近代物理研究（IMP）所计算、设计制造，线圈采用4.2K液氦浸泡式超导线圈，由合肥等离子体所设计制造（IPP）。 超导磁体的力学性能分析一直是超导磁体的基础问题。本文利用有限元分析方法，借助有限分析工具ANSYS、ADINA、OPERA等，分析了超导磁体的电磁场，着重模拟计算了SUPER-FRS/CR超导二极磁铁的电磁力作用；模拟了降温过程，计算了杜瓦、线圈热应力的作用；并对SUPER-FRS/CR超导线圈进行地震载荷作用的模拟。对以上不同的受力作用所遵循的不同的机械设计准则，进行不同的分析，最后计算结果证明设计的结构是安全、可靠的。由于超导线圈的结构复杂，导致在线圈拐角的地方应力有些集中，但是并不影响结构的可靠性。 本文还介绍了超导实验线圈的一些工艺设计，例如超导线圈的绕制，低温材料的选择，电流引线的设计工艺，以及VPI工艺。并对实验磁体进行了一系列的低温性能测试，例如短样测试、降温实验等，获得了一些重要的低温实验参数。这些参数将为以后超导磁体的研制提供宝贵的依据

永磁伺服电动机的矢量调速控制系统研究

永磁同步伺服电动机（PMSM）以其优越的性能广泛应用于各个机械传动领域。对PMSM的研究具有非常大的实际意义和价值，尤其对于我们单位目前在建大科学工程CSR。本文采用美国TI公司专用于电动机控制的数字信号处理器（DSP）芯片TMs320LF2406A作为核心，设计和开发全数字化的PMSM矢量调速控制系统。深入研究永磁同步电动机的矢量控制理论，建立起相应数学模型，然后提出矢量控制调速方案，并通过Mat lab仿真论证其可行性。介绍了硬件，软件结构及其实现。硬件方面主要介绍了控制电路各部分的设计和调试。在硬件基础上，用T工公司DSP汇编语言编程，实现电流环和速度环的双环控制，给出了系统程序和PWM信号产生的思路，并给出了主要模块的源程序。为了提高程序的运行效率，节省存储空间和提高系统的可靠性，程序中尽可能多的采用了数据表结构。

Immobilization of dipyridyl complex to magnetic nanoparticle via click chemistry as a recyclable catalyst for Suzuki cross-coupling reactions

A magnetic nanoparticle (MNP)-supported di(2-pyridyl)methanol palladium dichloride complex was prepared via click chemistry. The MNP-supported catalyst was evaluated in Suzuki coupling reaction in term of activity and recyclability in DMF. It was found to be highly efficient for Suzuki coupling reaction using aryl bromides as substrates and could be easily separated by an external magnet and reused in five consecutive runs without obvious loss of activity.

Thiacalix[4]arene-Supported Planar Ln(4) (Ln = Tb-III, Dy-III) Clusters: Toward Luminescent and Magnetic Bifunctional Materials

This paper reports the syntheses, crystal structures, and luminescent and magnetic properties of four tetranuclear Tb-III (1 and 3) and Dy-III (2 and 4) complexes supported by p-phenylthiacalix[4]arene (H(4)PTC4A) and p-tert-butylthiacalix-[4]arene (H(4)TC4A). All four frameworks can be formulated as [Ln(4)(III)(PTC4A/TC4A)(2)(mu(4)-OH)Cl-3(CH3OH)(2)(H2O)(3)], and some methanol and water solvent molecules are occupied in the interstices. The compounds are featured with a sandwichlike unit constructed by two tail-to-tail calixarene molecules and a planar tetragonal (mu(4)-OH)Ln(4) cluster. The photoluminescent analyses suggest that there is an efficient ligand-to-Ln(III) energy transfer for compounds 1-3 and H(4)PTC4A is a more efficient "antenna" than H(4)TC4A.