SFC引出静电偏转板运动控制系统设计实现

SFC（扇聚焦回旋加速器）是兰州重离子加速器HIRFL重要组成部分,其束流引出效率直接关系到整个加速器的运行效率。原SFC引出静电偏转板运动控制系统由于其设备陈旧,控制方式及控制精度都已不能满足调束的需求,加之位置检测功能的缺失,给调束带来极大不方便。基于此状态,本项目在有限的检修时间内,分两期实现了偏转板的位置检测和运动控制功能。在设计过程中,使用实际位置拟合测量数据的方法,提高了位置检测的精度,特别是用了特定的软件补偿算法消除机械传动回程差,大大提高了电机控制精度,目前整体控制精度在0.2mm左右。用户界面能够显示每个电机的相对位置、模拟动画、限位开关状态指示等信息。界面简洁直观,操作方便。系统自2014年夏季运行以来,稳定可靠,提高了供束效率,减少了故障时间,得到调束人员一致好评。SFC (Sector Focusing Cyclotron) is an important part of the Heavy Ion Research Facility in Lanzhou.The beam extraction efficiency of SFC is directly related to the efficiency of the whole accelerator. Because of the old equipment and control mode, as well as the low control accuracy of the SFC electrostatic deflection plate motor control, the motion control system was not able to meet the demand of beam tuning staff. In addition, there were no position detection function for this deflection plate; the beam tuning staff cannot get the current position of the deflection plate when they move these motors. Based on this situation, we designed and realized SFC motor control and position detection system in the summer maintain period in 2014 and 2015. In the design, we used the actual position to fit the measured voltage signal to improve the accuracy of position detection. Meanwhile, a specific compensation algorithm was designed to eliminate the mechanical transmission return difference, which greatly improved the motor control accuracy. At present, the overall control accuracy is about 0.2 mm. The user interface has numbers to shows the relative position of each motor and related animation, indicator led to show the status of each limit switches, easy operate buttons to control the motor moving. The system has been running stably and reliably since 2014. It has improved the efficiency of the beam tuning and reduced the fault time, so it is well praised by the beam tuning staff.     

CiADS超导直线加速器超导腔失效的分段补偿与冗余设计

加速器驱动次临界装置（ADS）对加速器运行稳定性和失束指标提出了前所未有的要求。对于超导直线加速器的研究发现,超导腔失效是失束的一个较大的来源,故针对超导腔的失效情况,本文提出分段补偿新方法,以提高高功率超导直线加速器的运行稳定性。提出的分段补偿方法与已有的全局补偿和局部补偿的方法相比,在保证加速器出口束流品质与无束损束流传输的同时,分段补偿束流能量,优化了参与能量补偿的超导腔数量,降低超导腔的备份功率源需求。论文最后针对CiADS的超导直线加速器的物理设计,做了分段补偿的多粒子模拟。结果表明,采用了分段补偿方法实现超导腔失效补偿的前提下,参与补偿过程中改变腔压的超导腔数量比例为48%,对功率源总的功率备份冗余需求小于20%。The accelerator driven subcritical system (ADS) has put forward unprecedented demands on the stability and beam trip of the accelerator operation. Depending on analysis, failure of the superconducting cavities is a major cause for beam trip of the superconducting cavity. Therefore, a new method of piecewise compensation is proposed to improve the stability of high power superconductivity linac. The piecewise compensation scheme proposed in this paper is compared with the existing global compensation and local compensation technology. While guaranteeing the beam quality of the accelerator and without beam loss transmission, the piecewise compensation method can optimize the number of superconducting cavities involved in energy compensation and reduce the demand for the backup redundancy of power sources of the superconducting cavities. At the end of the paper, the multi-particle simulation of piecewise compensation aims at the physical design of CiADS superconducting linac. The result shows that 48% of superconducting cavities modify the cavity's Epeak during the compensation process and the demanded redundancy of total power sources is less than 20% under the premise of successful compensation for the failure of superconducting cavities through the piecewise compensation method.     

整体分离环RFQ加速器的研究

阐述了北京大学整体分离环高频四极场（ＩＳＲＲＦＱ）加速器研究所取得的研究成果．分别论述了２６ＭＨｚ３００ｋｅＶＩＳＲＲＦＱ加速器结构、束流动力学设计、高频控制系统、束流试验装置及束流试验；分析了其对Ｎ＋、Ｏ＋、Ｏ－束流试验的研究结果；简述了２６ＭＨｚ１ＭｅＶＲＦＱ加速器束流动力学、加速腔设计及目前的进展 The status of the ISR RFQ accelerators in Peking University is described. The structure of ISR RFQ accelerator, beam dynamics calculation results by PARMTEQ, RF systems, beam transport lines and the beam test evolutions of a 26 MHz 300 keV ISR RFQ accelerator are also presented, respectively. The beam test results for N +, O +, O - particles are analyzed in detail. At last, the development of 1 MeV 26 MHz ISR RFQ accelerator is introduced briefly.     

SSC-LINAC重离子RFQ动力学模拟与研究

采用多粒子跟踪程序BEAMPATH 对SSC-LINAC 重离子RFQ 直线加速器进行动力学模拟,分别对RFQ 的接受度、高频特性、束流稳定性、空间电荷效应等进行了分析。该RFQ具有很大的纵向接受度,有利于束流在RFQ中的传输;高频特性研究表明,翼间电压设定在理论值以上时,该RFQ都能保持较好的束流特性;束流稳定性分析结果表明,该RFQ具有很大的束流失配容忍度;空间电荷效应研究表明,当束流强度低于0.5 mA时,束流传输不受影响。综合研究结果表明,53.667 MHz重离子RFQ具有较好的动力学特性,满足SSC-LINAC直线加速器的设计要求。The RFQ beam dynamics of a heavy ion linac was investigated in this paper and the BEAMPATH code was employed in this study. The main research was focused on the beam performances depending on longitudinal acceptance, RF properties, beam instability and space charge effect. The RFQ has large longitudinal acceptance in design, which brings the beam performances well. In the RF parameter study, the beam can keep good transmission in the acceleration even the vane voltage is larger than the theoretical value. It is also shown that the RFQ has a large robustness for the mismatch of the input beam by the analysis of the beam instability.Furthermore, the beam evolution is independent on the space charge effect when the beam current is less than 0.5 emA. The preliminary analysis of the beam dynamics shows that the 53.667 MHz heavy ion RFQ has a promising performance, which meets the requirements of SSC-LINAC.     

Tuning Characteristics of Frequency Difference for Zeeman—Birefringence He—Ne Dual Frequency Laser

Characteristics of frequency difference tuning of Zeeman-birefringence He-Ne dual frequency lasers (ZBDFLs) are explored.We design an automatic system of tuning cavity and power detection,which can tune the laser cavity and record the tuning curves of light power and frequency difference simultaneously.A synthetic phenomenon by Zeenman effect,mode pulling effect and birefringence effect is verified to exist in ZBDFLs.By analysing the tuning behaviour,this synthetic phenomenon is discovered and qualitatively explained for the first time.     

RIBLL次级束流强度的提高

为了提高兰州重离子加速器放射性次级束流线的束流强度,在现有的输运线基础上 ,设计了一个由一组超导螺线管和一个产生靶组成的次级束流增强系统.简要介绍了这个系统的束流光学设计原理和系统的初步设计.In order to meet the meeds of nuclear physic research, the beam intensity of RIBLL (Radioactivy Ion Beam Line in Lanzhou) should be improued. This can be carried out by two ways: increasing the primary beam intensity or improuing the transmission of the beam line. A system consisting of three superconducting solenoids and a new target frame is designed.     

MSC1210电源控制器的程序优化

为了解决兰州重离子研究装置( HIRFL ) 电源控制系统中的MSC1210 控制模块在调束过程中出现的各种故障,对其主芯片程序进行了优化设计。首先介绍了控制器的各种故障现象,分析了形成原因,然后制定了详细的设计方案,最后采用了以状态机为基础的指令接收过程、带校验机制的通信方式及远程指令复位等方法进行程序优化。实验室测试和现场使用结果表明,优化后的控制器运行稳定可靠,满足加速器的需求。The MSC1210 control module is one of the most important power supply controllers of Heavy Ion Research Facility in Lanzhou ( HIRFL ), but there are several problems during beam tuning. In order to deal with the problems,the main chip’s program was redesigned. In this paper we introduced the controller’s fault phenomena, and analyzed the reasons; then scheduled the optimized program in detail. Several methods were employed to improve the system performance, including instruction receiving process which is based on state machine, the communication mode with parity mechanism, and the remote instruction reset method. Both laboratory and commissioning tests indicate that the optimized controller is stable and reliable, and meet the operation requirement of HIRFL.     

CSR-LINAC IH-RFQ的高频电磁设计

中国科学院近代物理研究所在CSR-LINAC项目中设计了一台108.48 MHz的IH型RFQ直线加速器。该RFQ可以将质荷比为3~7的离子从4 keV/u加速到300 keV/u。在完成束流动力学设计的基础上,主要针对RFQ腔体的高频电磁设计展开了研究,同时利用了电磁场仿真和束流动力学模拟来研究腔体的四极场不平整度和二极场及其动力学影响。未经调谐的情况下,腔体的谐振频率为108.15 MHz,腔体空载品质因子Q₀为5 910,腔体功耗为123 kW。通过在支撑板两端增加底切的设计,将腔体的四极场不平整度由-21%~ 12%优化至±2.5%,满足了束流动力学要求。腔体的二极场为-3%~ -2.2%,使得束流在垂直方向小幅振荡,RFQ的垂直方向接受度减小5%。为了保证功率馈入时反射较小,将耦合器设置在临界耦合状态,耦合面积为940 mm2。为了补偿腔体的频率偏差和漂移,设计了调谐量分别为707和132 kHz的固定调谐器和可动调谐器。The 108.48 MHz IH type RFQ for CSR-LINAC project is under design at Institute of Modern Physics, Chinese Academy of Sciences. This RFQ can accelerate heavy ions with mass to charge ratio of 3~7 from 4 keV/u to 300 keV/u. According to the beam dynamics requirement, the RF structure design has been finished. The quadrupole field unflatness and dipole field of the cavity were studied by electromagnetic simulation and beam dynamics simulation. The frequency of the cavity without tuning is 108.15 MHz, the Q₀ of the cavity is 5910, and the RF power loss is 123 kW. The quadrupole field unflatness of ±2.5%,which was -21%~12% before optimizing, is achieved to meet dynamics requirement through the undercuts in cavity supporters. The dipole field of -3%~ -2.2% causes the oscillation of the beam center and acceptance reduction of 5%. The power coupler must be in critical coupling state with the coupling area of 940 mm2 for minimum reflection coefficient. The tuners, consist of coarse and fine tuners with frequency shift of 707 and 132 kHz respectively, is used for tuning of frequency deviation of the cavity.     

用于洁净核能源的ADS-EA方案

加速器驱动系统 (ADS)是一种新型的洁净能源装置 ,它采用加速器提供的强流高能量质子束驱动次临界的核反应堆 ,既有安全可靠和产生核废料少的优点 ,还可以处理传统反应堆留下的核废料 .能量放大器是一个基于回旋加速器组合的 ADS方案 ,由三级回旋加速器组成的加速器系统可以产生流强为12 m A和能量为1 .2 Ge V的质子束 (束流功率1 4.4MW) ,用以驱动1500 MW的核反应堆. Accelerator Driving System (ADS) is a new device for cleaning energy. A high intensity, high power proton beam provided by accelerators is used to drive a sub critical nuclear reactor. It is safe, reliable and can produce less nuclear waste, and also can be used to treat the nuclear waste from the classical reactor. An Energy Amplifier (EA), which is composed of three cyclotrons, is one type of ADS. It will be used to produce 14.4 MW proton beam (12 mA, 1.2 GeV) and to operate a 1 500 MW nuclear reactor.     

300MeV质子同步加速器概念设计优化（英文）

目前处于设计阶段的哈尔滨工业大学空间辐照效应装置,其核心部件是由1台10 MeV的注入器、1台300MeV的同步加速器以及输运线构成的加速器装置。同步加速器中引出的质子束流被用于辐照研究。基于装置的概念设计,优化了其同步加速器部分的设计。设计了新的磁聚焦结构,优化了基于新的磁聚焦结构的多圈注入系统的凸轨变化模式,提高了注入效率。为了更好地优化引出束流的时间结构,慢引出系统采用了RF knock-out的方法。为了满足精准辐照的要求,研究了RF Kicker的频率调制,发现RF Kicker的双频调制能使得引出束流更均匀。A research complex for aerospace radiation effects research is in the designing stage in Harbin Institute of Technology. Its core part is a proton accelerator complex, which consists of a 10 MeV injector, a 300 MeV synchrotron and beam transport lines. The proton beam extracted from the synchrotron is utilized for the radiation effects research. Based on the conceptual design, the design study for optimizing the synchrotron has been done. A new lattice design was worked out, and the decreasing pattern of the bump of the multi-turn injection system was optimized to increase the injection efficiency. In order to improve the time structure of the extracted beam, a RF knock-out method is employed in the slow extraction system. To meet the requirement of accurate control of dose, the frequency modulation of the RF kicker is well investigated, and the dual frequency modulation has been found to have a better performance for a uniform spill.     

基于遗传算法进行加速器自动调束

 介绍了遗传算法的基本理论，及其应用于加速器调束过程中的设计要点，给出基于遗传算法进行加速器自动调束的设计方法，并编写遗传算法程序针对HIRFL中的一段束流输运线进行了计算机仿真实验，证明了基于遗传算法进行自动调束的可行性，指出了自动调束技术的未来研究方向。     

An optical comb filter for the stochastic cooling system at the Nuclotron accelerator (Joint Institute for Nuclear Research,Russia)

To carry out longitudinal stochastic cooling of charge particle beams at the Nuclotron of the Joint Institute for Nuclear Research (Dubna), a unique optical comb filter was designed and developed. The designed filter has space-saving size, low insertion losses, and small dispersion. The comb filter tuning was automated using a specially designed software, which made it possible to reduce the tuning time and increase tuning accuracy up to several hertz. The designed filter with automatic tuning was successfully tested in an experiment on deuteron beam cooling. In this work, characteristics of the designed filter are presented and an algorithm of its automatic tuning is considered.     

基于变截面梁的光纤光栅线性无啁啾调谐

从理论上分析了利用变截面（等强度）弹性梁实现光纤光栅波长线性、无啁啾调谐的基本原理,给出了实现无啁啾波长调谐的弹性梁截面满足条件及其设计方案,并讨论了矩形等截面和变截面悬臂梁调谐方案的特点.理论分析与实验结果均表明,通过对变截面梁侧向施加载荷,可以实现光纤光栅中心波长的线性无啁啾调谐,且系统结构简单、易于设计.     

强流直线感应加速器束流智能调谐系统设计

 介绍了正在研究设计的调谐强流电子束束心轨迹的计算机智能系统。根据目前正在设计建造的 “神龙一号”加速器束流输运环境，为抑制束心螺旋运动，适应束输运磁场元件无散热装置，调谐过程中应尽量减少实验次数，智能调谐方法主要采用数值模拟和计算机克隆调谐和人工调谐相结合。以束心轨迹的数值模拟为基础，对束心位置调谐过程中的核心部分二极场调谐磁元件的调谐特性曲线进行了数值模拟，并与实验获得的调谐特性曲线进行了比较。获得了数值模拟和实验的初步结果。     

Development of a resonator with automatic tuning and coupling capability to minimize sample motion noise for in vivo EPR spectroscopy

EPR spectroscopy has been applied to measure free radicals in vivo; however, respiratory, cardiac, and other movements of living animals are a major source of noise and spectral distortion. Sample motions result in changes in resonator frequency, Q, and coupling. These instabilities limit the applications that can be performed and the quality of data that can be obtained. Therefore, it is of great importance to develop resonators with automatic tuning and automatic coupling capability. We report the development of automatic tuning and automatic coupling provisions for a 750-MHz transversely oriented electric field reentrant resonator using two electronically tunable high Q hyperabrupt varactor diodes and feedback loops. In both moving phantoms and living mice, these automatic coupling control and automatic tuning control provisions resulted in an 8- to 10-fold increase in signal-to-noise ratio.     

Mode-hop-free electro-optically tuned diode laser

A tunable external-cavity Littrow diode laser, with an intracavity electro-optical crystal, which combines a large mode-hop-free tuning range with high tuning speeds and high tuning accuracy, has been designed. A mode-hop-free single-mode tuning range of 50 GHz at 793 nm with an output power of 60 mW and tuning speeds of 1.5 GHz/micros is demonstrated. The instantaneous linewidth is smaller than 300 kHz. Generally mode-hop-free tuning is obtained when the elongation of the cavity is proportional to the cavity length measured anywhere across the beam. This elongation is achieved with an intracavity crystal in which the thickness, and thus the electric field inside it, varies across the beam.     

3.5 MeV无箔注入器束流调试

 3.5 MeV 注入器是“神龙一号”直线感应加速器的束源,在注入器束流调试中,首先通过数值模拟方法,初步确定束流过聚焦和聚焦不足两种极端情况下引出线圈输运磁场峰值的变化范围;然后以注入器出口束流波形为参考,通过实验调试找到了这两种情况下引出线圈输运磁场峰值的实际配置;再通过测量束流的剖面或发射度,在这两种配置中选定一个折中的引出线圈磁场配置,并最终确定了注入器输运磁场的总体配置。经过调试完成后的注入器束流为3.6 MeV,流强为2.8 kA,归一化边发射度为1 040 mm·mrad,达到了预期的指标。     

Development of a Resonator with Automatic Tuning and Coupling Capability to Minimize Sample Motion Noise for in Vivo EPR Spectroscopy

EPR spectroscopy has been applied to measure free radicals in vivo; however, respiratory, cardiac, and other movements of living animals are a major source of noise and spectral distortion. Sample motions result in changes in resonator frequency, Q, and coupling. These instabilities limit the applications that can be performed and the quality of data that can be obtained. Therefore, it is of great importance to develop resonators with automatic tuning and automatic coupling capability. We report the development of automatic tuning and automatic coupling provisions for a 750-MHz transversely oriented electric field reentrant resonator using two electronically tunable high Q hyperabrupt varactor diodes and feedback loops. In both moving phantoms and living mice, these automatic coupling control and automatic tuning control provisions resulted in an 8- to 10-fold increase in signal-to-noise ratio.     

光纤光栅温度调谐技术的发展与展望

介绍了光纤光栅调谐技术的基本原理。分别对基于半导体制冷器、电阻丝、双肩梁结构、镀膜光纤光栅的温度调谐方法进行了分析和综述。展望了光纤光栅温度调谐技术未来的发展。     

Manipulation of the overall polarization orientation in the focal volume of high numerical objectives

We propose an approach for tuning the three-dimensional polarization of a focusing subwavelength spot by a high numerical aperture objective. The incident beams are composed of a radially polarized beam, an azimuthally polarized beam, and a linearly polarized beam with three different weighting factors, respectively. A specially designed adjustable amplitude angular selector is also inserted at the back aperture of the objective for tuning the polarization azimuthally. It is shown that any desired overall polarization orientation can be obtained. We calculated the overall polarization orientation in the focal volume. It is found that the polar angle of the overall polarization orientation can be arbitrarily tuned by the combination of a radially polarized beam and a linearly polarized beam with different weighting factors, and the azimuthal angle can be tuned by rotating the orientation of the linearly polarized beam azimuthally.