HIRFL-CSR Tune值测量系统

兰州重离子加速器冷却储存环(HIRFL-CSR)工作点(Tune)测量系统已投入调束运行.采用FFT测量法,用白噪声信号做激励源,经功率放大并通过同轴开关切换将激励信号加载到垂直或水平的对称极板上,通过位置检测器(BPM)采集束流信号.将BPM两极板感应到的束流信号分别经前置放大器放大,再通过相位相差180°的合路器将差信号送入实时频谱仪进行傅里叶分析,从而计算出Tune值.本文主要介绍HIRFL-CSR工作点测量原理、系统构成以及测量结果.     

串列加速器超导增能器能量测量系统设计

设计了一套用于测量超导增能器束流能量的系统,并专门加工了测量装置,束流经准直后轰击金靶,通过测量散射粒子确定束流能量.探测器采用金硅面垒型半导体探测器,其信号经放大处理后进入多道分析器测量散射粒子能谱.另外基于Lab VIEW开发平台,编写了测控软件,完成了束流能量刻度、能量测量和工作相位设置,并采用CA Lab方式与...     

储存环束流丢失信号检测电路设计

丢束信号是上海光源束流测量系统需要提供的定时信号,用于触发数字BPM处理器libera记录丢束前束流数据来分析丢束原因,对提高加速器运行稳定性至关重要.本文详细介绍了丢束检测模块的原理,工艺设计及工艺测试情况,给出用RF信号源仿真束流信号的实验室离线测试结果.带束实验结果表明,本模块功能达到设计要求,可用于丢束数据的锁存.     

ADS注入器Ⅰ束流相位及能量测量系统设计

针对加速器驱动次临界系统(Accelerator Driven Sub-critical System,ADS)注入器Ⅰ束流调试要求,需要精确测量束流的相位和能量。本文研究束流的相位和能量高精度测量方法,设计了基于快速电流变压器(Fast Current Transformer,FCT)信号的相位及能量测量系统。该系统包括FCT探头、前端电子学、数据采集和处理三个部分,通过正交采样的方式实现束流的相位测量,然后利用飞行时间法实现束流能量的测量。测试结果表明,该系统在实验室测试相位分辨率为±0.8°,在线测试相位分辨率为±2°,满足直线加速器的设计要求。     

示波器嵌入式IOC研制及应用

宽带束流信号的量化和处理是加速器柬流诊断中的常见问题,上海光源束测组针对此应用开发出了示波器嵌入式IOC作为专用的束流信号处理器.该解决方案在EPICS构架的控制系统中具有即插即用的特点,目前已在上海光源注入器束团流强测量系统以及储存环填充模式测量系统中投入实用.本文介绍了部分宽带束流的测试结果.     

上海软X射线自由电子激光腔式束流位置测量系统

上海软X射线自由电子激光装置（Shanghai Soft X-ray Free Electron Laser, SXFEL）需1个分辨率达到亚μm量级的束流位置测量系统,并采用基于束流准直的方法实现波荡器段电子束与光子束的紧密重合。为此设计研制了1个由C波段腔式探头、单路混频至低中频的射频前端以及自主研发的专用数字信号束流位置处理器（digital beam position monitor processor, DBPM）构成的腔式束流位置测量（cavity beam position monitor, CBPM）系统。本文对系统的设计、软硬件结构、系统搭建进行了介绍,并基于漂移段搭建的3个紧邻的CBPM阵列完成了在线系统性能评估。束流实验结果表明,在束团电荷量为500 pC、系统动态范围在±800 μm的条件下,位置分辨率可达880 nm,这也是国内首次研制成功可在线运行的具有亚μm位置分辨率的CBPM系统。此外,采用CBPM的相位腔进行相对束团电荷量、束团到达时间的测量,其性能评估结果也均优于SXFEL设计要求。     

基于NiosⅡ嵌入式数据读出系统在CSNS DTL束流相位和能量测量中的应用

介绍了中国散裂中子源(CSNS,China Spallation Neutron Source)质子加速器DTL(Drift Tube Linac)束流相位和能量测量系统的数据获取系统的设计。在该系统中,基于Nios Ⅱ嵌入式系统及100 M以太网口来实现命令和数据的传输,使得该系统成为一个独立的束流相位测量及数据传输仪器系统,极大地简化了系统的结构。     

一种束流强度监测电路设计

介绍了一种新型的电流频率(I-F)转换电路,该电路用于测量平行板气体电离室的电流信号,配合实现了中国科学院近代物理研究所重离子治癌中束流强度的监测.治癌终端的临床试验表明该束流强度监测电路具有较高的灵敏度,能很好地应用在束流强度监测系统中.该电路也可以用于条形电离室信号的读出.     

合肥光源谐波法束团长度测量系统研制

同步辐射光与束流信号具有相同的时间结构,测量同步辐射光并基于频域的信号处理方法可得到束团的长度。基于该原理,研制了采用谐波法测量束团长度的系统。该系统用高速光电接收器将同步光转换为电信号,然后采集该信号的四路频率分量,计算得到束团长度。阐述了该系统的软硬件设计,并应用该系统测量了束团长度随流强的变化规律,与条纹相机的测量结果相吻合。     

上海光源储存环束流轨道联锁系统升级

针对上海光源机器故障分析的需求,对原有储存环束流轨道联锁系统进行升级,实现对储存环束流位置测量系统中140台束流位置监测器(Beam Position Monitor,BPM)电子学输出的联锁信号进行标记,同时锁存丟束过程中所有BPM电子学中的逐圈轨道数据。联锁信号的处理与锁存触发信号的输出在FPGA(Field Programmable Gate Array)内完成。该系统集成至储存环的物理实验与工业控制系统(Experimental Physics and Industrial Control System,EPICS)控制系统之中。束流检测实验表明,该系统能够准确区分不同BPM电子学输出的联锁信号,同时锁存丟束时逐圈轨道数据,并通过该系统观测到了储存环束流丢失过程中的逐圈轨道变化。     

100MeV强流回旋加速器径向靶的研制

在100MeV强流回旋加速器调试过程中,需对束流在加速器内的轴向和径向参数进行测量。径向靶系统是束流诊断系统中用于获取上述参数的主要部件,本文研制了3套阻挡式径向靶系统,并安装到加速器主体,获得了束流在连续加速过程中的轴向和径向分布,为加速器运行提供了相应束流参数,并为后续加速器升级工作提供了必要的条件。     

Improvement of ultrasonic testing by phased arrays

Methods for defect reconstruction and classification using the flexible and fast electronic beam forming with phased arrays have been described. Using the electronic sector scan, a reflecting point is represented as a short circular curve, the length of which is dependent upon beam width and system sensitivity. By superimposing all sector displays on a storage tube, a defect is reconstructed by the inner envelope of the circular curves. If, instead of the circular curves, only their centers (intensity maxima) are recorded, a defect is reconstructed by individual image points. This representation has the important advantage that is to a large extent independent of beam width and system sensitivity. The reconstruction by compound scanning which includes, as a special case, the conventional focused probe technique with B-scan presentation, has a high redundancy; and in the case of testing coarse grained materials, the coherent noise is essentially reduced (intensity averaging). By recording the maximum echo height during sector scanning with open beam, a compound scan amplitude-locus curve (VAOK) is generated which represents the directivity of the defect.     

Measurement of beam power and profile for DNB on HT-7 tokamak

In normal experimental operation, a diagnostic neutral beam (DNB) can produce 6 A of extracted beam current in hydrogen at an energy of 49 keV with a pulse length of 100 ms. Hydrogen and deuterium beams can be produced as well. The diagnostic neutral beam has been added to the diagnostic set so that charge-exchange recombination spectroscopy (CXRS) can be used to acquire ion temperature and rotation. The beam power and beam profile distribution of the DNB injection can be obtained with a thermocouple probe measurement system on the HT-7 superconducting tokamak. The thermocouple probe measurement system with 13 thermocouples crossly distributed on the probe plate was used to measure the temperature rise of each coppery target, so the profile distribution of the ion/neutral beam was obtained by calculation. In this paper, the structure of the probe plate on the DNB for HT-7 tokamak and some measurement results are presented.     

环形单针双束流截面测量技术

利用一个三维环形探针对离子束进行旋转扫描，可以同时测量到两个束流截面的大小和位置，估算出二截面附近的聚焦梯度以及束腰的移动。     

Recent status of the Kiev nuclear probe

The modified Van de Graaff accelerator with proton beam energy W ? 3 MeV has been installed and put into operation at the TMM laboratory in Kiev. The laboratory incorporates the nuclear probe (NP) beam line, coupled to this accelerator. A short version of an optimized probe-forming system (PFS) has been developed for the Kiev NP. The system is based on divided triplet of the magnetic quadrupole lenses (MQLs). This PFS has two working regimes for the probe operations. The results of numerical calculations of the geometrical and ion-optical parameters of the PFS are presented. It is shown that this versatile PFS is a promising design for a modern nuclear nano-probe. A new precision adjustable MQL has been designed. Three lenses, the slit systems and target chamber are manufactured and installed at the Kiev probe beam line. Also a new data acquisition system for the Kiev NP is being developed.     

Laboratory and In-Beam Tests of a Novel Real-Time Beam Monitor for Hadrontherapy

Real time monitoring of hadrontherapy beam intensity and profile is a critical issue for the optimization of dose delivery to carcinogenic tissue, patient safety and operation of the accelerator complex. For this purpose an innovative beam monitor, secondary electron emission for low interception monitoring (SLIM) is being developed in the framework of the EC-funded silicon ultra-fast cameras for electrons and gamma sources in medical application (SUCIMA) project. The detector system is based on the secondary emission of electrons by a nonperturbative, sub-micron thick Al foil placed directly in the extracted beam path. The secondary electrons, accelerated by an electrostatic focusing system, are detected by a monolithic silicon position-sensitive sensor, which provides the beam intensity and its position with a precision of 1 mm at a 10 kHz frame rate. The results of the laboratory tests of the first system prototype with thermoionic electrons emitted from a hot Tungsten wire are presented together with the measurements performed on a low intensity hadron beam at the Cyclotron of the Joint Research Centre in Ispra.     

基于BEPC Ⅱ的数字束流位置探测器信号处理算法的FPGA实现

数字束流位置探测器(BPM)算法是数字BPM系统最核心的部分,其对束流位置测量的精度起决定作用。本文在完成数字BPM算法MATLAB模拟工作的基础上,将模拟优选出的数字BPM算法在自制的电子学硬件上进行FPGA实现。首先介绍了数字BPM算法的总体设计和实现方案;其次介绍了数字BPM算法各功能模块的设计原理及其在FPGA中的具体实现方法;最后在输入信号频率499.8 MHz、强度-10 dBm、BPM探头灵敏度系数23的条件下进行了实验室测试。实验结果显示：逐圈位置分辨达2.96 μm,快响应位置分辨达0.65 μm,闭轨位置分辨达0.33 μm,验证了本算法在束流位置测量中具有良好性能。     

以离子数比为变量的束晕-混沌模拟控制

文章改变以往习惯于以离子束均方根半径等为控制变量的束晕-混沌模拟控制方法，取匹配半径外离子数与总离子数之比为控制变量，并构造一对数函数控制器，以进行束晕-混沌控制的模拟研究。结果显示，新的控制方法对强流加速器中5种初始分布的离子束均有较好的控制效果。由于此方法只需探测跨越匹配半径的离子数，在实验上有实施的可能。      

北京ISOL项目进展

北京ISOL（北京在线分离丰中子束流装置,亦简称BISOL）是由中国原子能科学研究院和北京大学联合提出的一台大科学装置。项目建设包括反应堆与加速器驱动放射性核束离子源、强流氘离子加速器、高功率靶站与核能材料辐照装置、放射性核束后加速器、放射性核束实验站等。装置建设方案已初步确定,装置建成后可产生较国内外现有装置强度高1~2个量级的极端丰中子束流,可开展学科基础前沿放射性核束物理的创新研究,同时兼顾先进核能系统开发和多种核技术应用的需求。