高电压锯齿波聚束器的设计研制

近些年来,使用锯齿波直接形成的方法建造非谐振型聚束器在国内及国际均得到了广泛的应用。由于电子技术及机械加工工艺的飞速发展和更高功率电子管的出现,可以设计出更高指标的聚束器,进而可以有效提高束线的匹配效率及运行稳定度。对兰州重离子加速器源束线新的高电压锯齿波聚束器的研制进行了详细阐述,由于该聚束器具有目前国际同类型设备中最高的电压、频率以及相对苛刻的现场条件限制,故还对设计中所涉及的工程实施方案进行了有效补充和完善。     

Preliminary study of a niobium quarter-wave prototype cavity for a heavy-ion superconducting linac

Superconducting quarter-wave resonators,due to their compactness and their convenient shape for tuning and coupling,are very attractive for low-β beam acceleration.In this paper,two types of cavities with different geometry have been numerically simulated the first type with larger capacitive load in the beam line and the second type of lollipop-shape for 100 MHz,β=0.06 beams then the relative electromagnetic parameters and geometric sizes have been compared.It is found that the second type,whose structural design is optimized with the conical stem and shaping drift-tube,can support the better accelerating performance.At the end of the paper,some structural deformation effects on frequency shifts and appropriate solutions have been discussed.     

2.45 GHz ECR离子源的微波阻抗匹配

ECR离子源的等离子体阻抗对其微波传输与阻抗匹配设计至关重要。在中国科学院近代物理研究所现有的2.45 GHz ECR 质子源上,对等离子体阻抗进行了测量。首先用水吸收负载代替等离子体负载测量得到了所用微波窗阻抗,然后根据质子源测量数据,推算得到了等离子体阻抗。实验结果表明,脊波导输出端阻抗与后续负载不完全匹配,等离子体阻抗随微波功率变化呈非线性。这些结果为ECR离子源过渡匹配和微波窗的设计提供了参考依据。Plasma impedance of an ECR ion source is important for microwave transmission and impedance matching design. Plasma impedance was measured indirectly with the 2.45 GHz ECR proton source at the Institute of Modern Physics, Chinese Academy of Sciences. In the test, we got microwave window mpedance by using water absorption load instead of plasma load, and the source plasma impedance was derived from the test data with the 2.45 GHz ECR proton source and microwave window impedance. The experimental results show that ridge waveguide output impedance and the subsequent load does not exactly match, plasma impedance variation is nonlinear with microwave power. The achievedresult is useful in the design of ridged waveguide and microwave window.     

强流ECR离子源引出系统研究

为了提高强流ECR 离子源的引出束流品质,分别设计了1# 和2# 引出系统,利用束流引出模拟软件PBGUNS 对1# 和2# 引出系统进行了质子束流引出与传输的模拟计算,结合实际测得的发射度数据分析引出系统,发现2# 引出系统比1# 引出系统引出束流品质高。对ECR 离子源引出系统的电势等位线分布等参数引起的球差进行了简单数学推导及MATLAB 绘图,并结合1# 和2# 引出系统束流相图模拟结果证明了球差会使引出束流品质有效发射度增长,通过适当加大电极孔径可改善束流聚焦情况,得到了束流光学聚焦较好的束流引出系统设计。To improve the quality of extracted ion beam from a high current ECR ion source, 1# and 2# extraction systems were designed and tested. The PBGUNS code was used to simulate the 1# and 2# extraction systems of proton ion beam. The emittance measurement results with the two different extraction systems were compared and analyzed with the simulation, the conclusion that more high quality beam extracted from 2# system than 1# system was got. The formula derivation of ECR ion source extraction system spherical aberration and MATLAB drawing was done by the analyzing on the distribution of extraction field equipotentials, effective emittance increasing caused by spherical berration was proved by 1# and 2# extraction systems beam phase space simulation result, beam focusing would be improved if electrode hole size increasing appropriately and a general concept on good optics focusing of ion beam extraction system was proposed finally.     

医用重离子回旋加速器引出系统设计

紧凑型回旋加速器作为重离子医学专用装置同步加速器的注入器,其引出系统设计所用的磁场为TOSCA模型计算磁场。通过单粒子轨道计算确定引出系统的元件类型及基本参数;通过多粒子跟踪确定最终的元件参数和束流参数。为了提高引出效率,改善引出束流品质,在引出位置磁场梯度较大的位置,安放了一块C型磁铁,以改善此处的磁场梯度。同时,为了消除此C型磁铁对主磁场的影响,在此区域安放了一对线圈。计算结果表明引出系统的设计能够保证引出束流的强度和品质符合同步加速器的要求。     

基于太赫兹技术的药物检测

鉴于太赫兹辐射特有的光谱分辨性、功能性成像特点以及良好的穿透性和安全性等,太赫兹波谱技术迅速成为物质分析与检测等的重要工具。文章基于太赫兹时域光谱技术的实验数据,结合泛函密度理论(DFT)和HIPHOP模型,对一系列降糖类药物进行分子解析和功能基团识别;结合支持向量机理论(SVM),对4种郁金类中草药进行分析识别;并结合差式扫描量热法对葡萄糖-水合物的结晶水状态进行测定;最后对太赫兹时域技术在药物检测方面的优势和不足做了进一步的分析与展望。     

Charge state distribution analysis of Al and Pb ions from thelaser ion source at IMP

A prototype laser ion source that could demonstrate the possibility of producing intense pulsed high charge state ion beams has been established with a commercial Nd:YAG laser (E_max=3 J,1064 nm,8-10 ns) to produce laser plasma for the research of Laser Ion Source (LIS). At the laser ion source test bench,high purity (99.998%) aluminum and lead targets have been tested for laser plasma experiment. An Electrostatic Ion Analyzer (EIA) and Electron Multiply Tube (EMT) detector were used to analyze the charge state and energy distribution of the ions produced by the laser ion source. The maximum charge states of Al¹²⁺ and Pb⁷⁺ were achieved. The results will be presented and discussed in this paper.     

HIRFL-CSR实验环高频同轴谐振腔设计原理

介绍了同步加速器高频铁氧体加载腔体的设计原理和设计计算过程。 详细说明了腔体加载铁氧体材料的作用和意义, 并对传统的传输线理论计算结果、 CST(Computer Simulation Technology)软件模拟计算结果和实际腔体测量结果进行了比较。 In this paper, the principle and the process of design and calculation based on RF ferrite loaded coaxial cavity in synchrotron are presented. The function and significance of cavity loaded by ferrite are elaborated in detail. Then the calculated results by traditional transmission line theory, software simulated results by Computer Simulation Technology(CST ) and the actual cavity measured results are compared.     

RF system design and measurement of HIRF-CSRe

An RF system for the CSRe （cooling storage experimental ring） is designed and manufactured domestically. The present paper mainly describes the RF system design in five main sections： ferrite ring, RF cavity, RF generator, low level system and cavity cooling. The cavity is based on a type of coaxial resonator which is shorted at the end with one gap and loaded with domestic ferrite rings. The RF generator is designed in the push-pull mode and the low level control system is based on a DSP＋FGPA＋DDS＋USB interface and has three feedback loops. Finally we give the results of the measurement on our system.     

耦合带状线定向耦合器大功率合成器的设计

介绍了直线加速器高频全固态功率源中大功率合成器件-3 dB定向耦合器的理论计算和工程设计过程, 该合成器工作频率80.5 MHz, 输出连续波功率大于20 kW。 分析了合成器的功率容量, 并对相应的理论计算结果、 CST (Computer Simulation Technology)软件模拟计算结果和实际功率合成器件测量结果进行了比较。 通过比较得出, CST仿真结果与测试结果基本一致, 隔离度和电压驻波比等实测指标优于设计指标, 只有耦合度与设计指标有些偏差, 总体上达到了预期的设计要求。 在输出功率20 kW时, 取样波形无失真, 合成器无明显温升, 满足固态功率源大功率稳定运行的要求。 The principle of design and calculation of the power synthesis in the solid state amplifier are described in this paper. The working frequency of the synthesizer is 80.5 MHz. The output continuous wave power is more than 20 kW; The synthesizer power capacity is analyzed. The theoretical calculation results, Computer Simulation Technology (CST) simulated results are compared with the measured results of the actual 3 dB couplers. The analysis of the measured results and CST calculated results shows that the simulation is in agreement with the measurement results which meet the design requirements of the solid state amplifier. Except the coupling coefficient, the isolation, the VSWR and other parameters are better than the design target. When the output power is 20 kW, the sampling waveform has no deform and the temperature of the synthesizer is stable.