A Penning Ion Source for Multiply Charged Ions

The ion source described in this contribution allows the production of considerable ion beam intensities of highly charged ions. The electron density is increased by an additional electron gun. The decrease-of the ratio of neighbouring charge states is similar to the decrease of the ratio of the ionization cross sections by electron impact from which one event ionization processes are assumed to be of major importance in the performance of this source.     

Power Supplies for Cold Cathode Penning Discharge Ion Sources

For the generation of heavy ions at high charge states, the cold-cathode Penning discharge ion source requires a power supply capable of both the high potential essential for striking an arc and the high current for sustaining it. A series-regulated power supply developed at Oak Ridge provides up to 6 kV of striking voltage and up to 12 amperes of arc current. The power supply operates in a constant current mode with the arc voltage dependent on the gas pressure in the ion source. With this source in ORIC, the typical operating conditions are 5 to 10 amperes arc current, 600 to 2000 volts arc potential, and 5 to 20 kW power dissipation in the arc. A larger power supply is planned for extending the arc current to about 25 amperes. Various arrangements, including pre-regulators and multiple power supplies, are under consideration to reduce power dissipation in the series regulator tubes.     

Electron Cyclotron Resonance in a Penning Ion Source

Electron cyclotron resonance was detected in a Penning source by measuring the electron temperature as obtained from the x-ray emission spectrum. The resonance is only present if flat cathodes are used.     

中子管内潘宁离子源的建模与控制

由于中子管内离子源电流滞后于储存器电流,导致离子源电流的调节速度和稳定性不够高,进而影响中子产额的稳定性。本文在分析大量实验数据的基础上,建立了中子管离子源的数学模型,设计出相应的PID控制算法。经测试表明：所构建的离子源模型与实际离子源工作情况符合较好,改进的控制算法能减少稳定离子源电流所需时间,提高中子产额的稳定性。     

Performance of a Penning Ion Source in the Oak Ridge Isochronous Cyclotron

One year of operation of a heavy-ion Penning source in the Oak Ridge Isochronous Cyclotron has resulted in the acceleration of a number of isotopes of 17 elements, ranging from boron to tantalum. The method of positive identification of these beams and the operational techniques used to develop certain beams are described. Comparison of the extracted particle current for a given charge state with the calculated ionization potential has resulted in a systematic understanding of particle currents to be expected for undeveloped beams. In particular, shell effects and total ionization potential must both be considered in predicting beam intensities. The particle currents of ArR8+ Ar9+ and Ar10+ provide a sensitive test for the comparison of multiple and single impact calculations. The data are in agreement with multiple impact calculations. Also, low energy x-rays emitted from the Penning source have been detected and the observed spectra characterize the two modes of source operation.     

紧凑型强流ECR源

建立了１台紧凑型强流ＥＣＲ源。共振磁场由１个小电磁线圈及软铁回路产生,磁场可调,能保证放电处于最佳条件。研究了气压,微波功率及共振场对放电的影响。在５５０Ｗ的放电功率下,从直径４ｍｍ引出孔引出了３５ｍＡ的Ｈ＾＋离子束,引出Ｈ＾＋离子的质子比超过９０％,从源中还引出了７ｍＡＯ＾＋、８ｍＡＮ＾＋、１２ｍＡ Ａｒ＾＋的束流。     

Discharge Characteristics of Large-Area High-Power RF Ion Source for Positive and Negative Neutral Beam Injectors

A large-area high-power radio-frequency(RF) driven ion source was developed for positive and negative neutral beam injectors at the Korea Atomic Energy Research Institute(KAERI). The RF ion source consists of a driver region, including a helical antenna and a discharge chamber, and an expansion region. RF power can be transferred at up to 10 kW with a fixed frequency of 2 MHz through an optimized RF matching system. An actively water-cooled Faraday shield is located inside the driver region of the ion source for the stable and steady-state operations of high-power RF discharge. Plasma ignition of the ion source is initiated by the injection of argongas without a starter-filament heating, and the argon-gas is then slowly exchanged by the injection of hydrogen-gas to produce pure hydrogen plasmas. The uniformities of the plasma parameter,such as a plasma density and an electron temperature, are measured at the lowest area of the driver region using two RF-compensated electrostatic probes along the direction of the shortand long-dimensions of the driver region. The plasma parameters will be compared with those obtained at the lowest area of the expansion bucket to analyze the plasma expansion properties from the driver region to the expansion region.     

The Development of a Megawatt-Level High Current Ion Source

Neutral beam injection is one of the main plasma heating methods in nuclear fusion devices. In order to support the scientific study of the Experimental Advanced Superconducting Tokamak (EAST), a megawatt-level high current ion source is designed and manufactured in the ASIPP, and the progress and preliminary test results will be presented in this paper.     

CIAE强流ECR离子源研制

本文介绍了研制的一台强流ECR微波离子源,其能从7 mm直径的圆孔引出大于150 mA的氢离子束(75 keV),质子比达90%。该离子源采用独特的结构提高了离子源寿命。离子源在75 keV、110 mA束流条件下连续工作超过220 h,束流中断2次,不间断工作时间超过150 h。     

强流负氢离子源发射度测量仪研制

在加速器技术研究中,束流发射度是反映束流品质的重要物理参数,也是加速器和束流传输线设计的重要依据。100 MeV回旋加速器采用18 mA强流负氢离子源来产生负氢束,为了准确测量离子源的发射度,研制了一台强流负氢离子源发射度测量仪,介绍了其基本原理、机械设计和实验结果,得到了离子源的发射度信息,为100 MeV回旋加速器的设计提供了发射度参数。     

Using Adaptive Discrete-Time Gas Supply Control for Long Pulse Arc Discharge of Ion Source on NBI

A control model of gas supply system is introduced for ion source and an adaptive discrete-time control algorithm to regulate the hydrogen injection. A real-time feedback control system （RFCS） is designed to control the gas supply for ion source based on the control model and the discrete-time control algorithm. The experimental results have proved that RFCS could regulate the gas supply smoothly, suppress the arc＇s abrupt over-current at the end of the ion source discharging, prolong the discharge pulse and stabilize the ion concentration. With RFCS, the ion source for neutral beam injection has reached its longest pulse with a length of 4.5 seconds in a stable status.     

Prototype Target Ion Source Experimental Apparatus for High Intensity RIB Generation in Reactor

<正>A prototype target ion source experimental apparatus for high intensity radioactive ion beam(RIB)generation in reactor was developed,and its schematic is showed in Fig.1.The experimental apparatus consists of ion source,heater,quadruples,steerer,beam diagnostics unit and vacuum system.The cathode of ion source is     

氧负离子潘宁源的实验研究

文章涉及用袖珍永磁潘宁源产生毫安级氧负离子束的实验研究。给出了磁场、不同阴极材料及源的离子发射孔对引出氧负离子束的影响。目前,该类型离子源已成功地用于正负氧离子同时加速的1MVISR RFQ加速器上。     

Factors Influencing the Electron Yield of Needle-Ring Pulsed Corona Discharge Electron Source for Negative Ion Mobility Spectrometer

A simple negative ion mobility spectrometer （IMS） is designed and used to investi- gate the factors that influence the number and efficiency of electrons generated by the needle-ring pulsed corona discharge electron source. Simulation with Ansoft Maxwell 12 is carried out to analyze the electric field distribution within the IMS, and to offer the basis and foundation for analyzing the measurement results. The measurement results of the quantities of electrons show that when the drift electric field strength and the ring inner diameter rise, both the number of ef- fective electrons and the effective electron rate are increased. When the discharge voltage becomes stronger, the number of effective electrons goes up while the effective electron rate goes down. In light of the simulation results, mechanisms underlying the effects of drift electric field strength, ring inner diameter, and discharge voltage on the effective electron number and effective electron rate are discussed. These will make great sense for designing negative ion mode IMS using the needle-ring pulsed corona discharge as the electron source.     

Characteristics of a Cold Cathode Type Penning Source and Low Energy Isotope Separation of High Charge States

Measurements of voltage-, current-and gas flow dependencies of a cold cathode Penning source, using different cathode materials, are reported. The influence of the discharge parameters (arc voltage, arc current, magnetic field and gas flow) on the production of higher charge states was studied. The highest observed charge states were Ar9+ , Kr12+ Xe13+ The cold cathode type Penning source with radial extraction proves to have sufficiently low energy spread to permit isotope separation in the source-magnet field. Results for Ar2+, Kr4+ and Xe7+ as well as emittance measurements are given.     

永磁强流ECR离子源

文章介绍一台2.45 GHz永磁强流ECR离子源,其直径为10 cm,长10 cm,重量不足5 kg,可工作在直流模式和脉冲模式.脉冲模式引出的氢离子束峰值流强大于100 mA,束流密度达到500 mA/cm2;直流模式引出束流达到60 mA,束流密度为300 mA/cm2.两种模式的质子比均达到80%.     

A Repetitive Nanosecond Pulse Source for Generation of Large Volume Streamer Discharge

Using a unipolar pulse with the rise time and the pulse duration in the order of microsecond as the primary pulse, a nanosecond pulse with the repetitive frequency of several kilohertz is generated by a spark gap switch. By varying both the inter-pulse duration and the pulse frequency, the voltage recovery rate of the spark gap switch is investigated at different working conditions such as the gas pressure, the gas composition as well as the bias voltage. The results reveal that either increase in gas pressure or addition of SF6 to the air can increase the voltage recovery rate. The effect of gas composition on the voltage recovery rate is discussed based on the transferring and distribution of the residual space charges. The repetitive nanosecond pulse source is also applied to the generation of large volume, and the discharge currents are measured to investigate the effect of pulse repetition rate on the large volume streamer discharge.     

Design issues of the High Voltage platform and feedthrough for the ITER NBI Ion Source

In the ITER heating Neutral Beam Injector (NBI), a High Voltage air-insulated platform (named High Voltage Deck, HVD) will be installed to host the Ion Source and Extractor Power supply system and associated diagnostics referred to ?1 MV DC potential. All power and control cables are routed from the HVD via a feedthrough (HV bushing) to the gas insulated transmission line which feeds the Injector.The paper focuses on insulation and mechanical issues for both HVD and HV bushing which are very special components, far from the present industrial standards as far as voltage (?1 MV DC) and dimensions are concerned. For this purpose, a preliminary design of the HVD has been carried out as concerns the mechanical structure and external shield. Then, the structure has been verified with a seismic analysis applying the seismic load excitation specified for the ITER construction site (Cadarache) and carrying out verifications according to relevant international standards. As regards the HV bushing design, proposals for the complex inner conductor structure and for interfaces to the HVD and transmission line are outlined; alternative installation layouts (aside or underneath the HVD) are compared from both mechanical and electrical points of view.