Design and operating characteristics of new type cold cathode ion source

In this work, the design and performance of new type ion source are described. The discharge mechanism of the source is based on creating an arc discharge through a saddle electric field inside the discharge tube. The saddle electric field is created by immersing an annular anode inside the discharge tube covered from the upper and lower ends with two flanges. These two flanges act as cathodes. The discharge tube is surrounded by a solenoid coil which produces an axial magnetic field (up to 400 G) measured at the center of the source. Measurements have been performed to find out the influence of arc power, pressure, discharge voltage, magnetic field, and extracting voltage on the ion source properties. The source yields an argon ion current of approximately 0.6 mA and electron current of approximately 4 mA at normal operating conditions (extraction voltage V(ex)=7 kV, pressure of 5.5x10(-4) Torr, V(arc)=400 V, I(arc)=1 A, B=200 G). It showed an energy spread of 20 eV at a discharge voltage of 400 V and an extraction voltage of 3 kV.     

洁净正负压气源及气密性检查装置的可靠性分析

某自带高洁净度正负压气源对特定用途的容器作干燥处理和气密性检查的装置,涉及的元器件较多,各元器件是否可靠,直接影响到对容器进行干燥处理的效果和气密性检查的真实性结果。这里介绍了该装置的工作原理及流程、主要技术参数及要求,从构成该装置的主要元器件出发,分析影响该系统可靠性的因素,探索其系统可靠性分析的方法,研究的结果可应用在类似系统的可靠性分析。     

端部中空离子源的磁场测量

研究了端部中空离子源的磁路设计.在简要叙述端部中空离子源的基本原理及其对磁场要求的基础上,考虑了在设计离子源磁路时的关键问题和解决方法,并给出了实验结果和分析结论.     

Generation of an ion beam in a glow-discharge source

A mechanism of ion extraction from a glow-discharge ion source based on a hollow cathode and used for elemental analysis of solids, is considered Experiments have shown that two oppositely directed ion flows are formed from ions produced in the region of negative glow-discharge fluorescence. One flow has an ion energy ≥ 100 eV, is directed to the cathode, and bombards and sputters the analyzed sample. The sputtered atoms diffuse into the negative-glow region and are ionized. The second flow (low-energy ions) is extracted from the same negative-glow region and transported from the cathode to the surface of the anode chamber owing to an ambipolar diffusion. These ions are extracted from a hole in the anode chamber of a standard ion source by an electric field and are used for mass-spectrum analysis. The energy-distribution width for these ions is ∼5 eV. The intensity of the ion beam extracted from the anode hole is an order of magnitude higher than the intensity of the ion beam extracted from the cathode region. Original Russian Text ? G.G. Sikharulidze, 2009, published in Pribory i Tekhnika Eksperimenta, 2009, No. 2, pp. 105–109.     

Optimizing a microwave gas ion source for continuous-flow accelerator mass spectrometry

A 2.45 GHz microwave ion source coupled with a magnesium charge exchange canal (C × C) has been successfully adapted to a large acceptance radiocarbon accelerator mass spectrometry system at the National Ocean Sciences Accelerator Mass Spectrometry (AMS) Facility, Woods Hole Oceanographic Institution. CO(2) samples from various preparation sources are injected into the source through a glass capillary at 370 μl∕min. Routine system parameters are about 120-140 μA of negative (12)C current after the C × C, leading to about 400 (14)C counts per second for a modern sample and implying a system efficiency of 0.2%. While these parameters already allow us to perform high-quality AMS analyses on large samples, we are working on ways to improve the output of the ion source regarding emittance and efficiency. Modeling calculations suggest modifications in the extraction triode geometry, shape, and size of the plasma chamber could improve emittance and, hence, ion transport efficiency. Results of experimental tests of these modifications are presented.     

An ion source with an ejecting U-shaped electrode

The design of an ion source is described, in which any replacement of diaphragms of electron and ion optics can be performed and, as a result, new technical characteristics of the source can be obtained. The extended capabilities of the ion source are substantial for revealing the causes of such a phenomenon as a spread in measurements of lifetimes of negative ions, which are performed using instruments of different types. The use of an ejecting U-shaped electrode in the source allowed the intensity of recorded signals to be increased by a factor of at least 2.     

Emergency power source for an ion vacuum pump

This note describes a simple high-voltage dc generator which serves as an emergency power source for an ion vacuum pump during power interruptions, or failure of the main supply.     

MDT在气密性检测及干燥处理装置设计中的应用

这里应用Autodesk公司的大众化三维实体造型和仿真分析软件MDT(Mechanical Desktop)系统对气密性检测及干燥处理装置进行了设计，并对应用过程中出现的问题作了分析与研究，为CAD／CAE／CAM技术在产品开发过程中的应用作了尝试和探索。     

Investigations on the structure of the extracted ion beam from an electron cyclotron resonance ion source

Using improved beam diagnostic tools, the structure of an ion beam extracted from an electron cyclotron resonance ion source (ECRIS) becomes visible. Especially viewing targets to display the beam profile and pepper pot devices for emittance measurements turned out to be very useful. On the contrary, diagnostic tools integrating over one space coordinate like wire harps for profile measurements or slit-slit devices, respectively slit-grid devices to measure the emittance might be applicable for beam transport investigations in a quadrupole channel, but are not very meaningful for investigations regarding the given ECRIS symmetry. Here we try to reproduce the experimentally found structure on the ion beam by simulation. For the simulation, a certain model has to be used to reproduce the experimental results. The model is also described in this paper.     

Optimization of gas utilization efficiency for short-pulsed electron cyclotron resonance ion source

Numerical analysis of (6)He atoms utilizing efficiency in the ion source with powerful gyrotron heating is performed in present work using zero-dimensional balanced model of ECR discharge in a magnetic trap. Two ways of creation of ion source with high gas utilization efficiency (up to 60%-90%) are suggested.     

MAT253气体质谱仪离子源系统故障排除

MAT253气体质谱仪出现10kV高压无输出故障,但高压单元本身正常,本文分析了故障产生的原因。     

Decrease in the ignition pressure of anomalous glow discharge in a magnetron with an ion-beam-irradiated cathode

The influence of an ion beam injected along the axis of the anode electrode of a planar magnetron on the initiation of an anomalous low-pressure glow discharge in a magnetron has been considered. The characteristics of the discharge ignition at pressures <8 × 10^?2 Pa and the properties of a planar magnetron with an ion-beam-irradiated cathode are determined. It is established that the discharge ignition voltage decreases with an increase in the ion energy and exhibits a threshold behavior as a function of the ion-beam current. It is shown that there is a prospect for extending the functional capabilities of planar magnetrons through matching of the modes of sputtering of the magnetron anode and cathode by an ion beam and plasma ions of an anomalous glow discharge, respectively.     

The impact of plasma-wall interaction on the gas mixing efficiency in electron cyclotron resonance ion source

It is generally accepted that different effects are necessary to explain the gas mixing method of increasing the output of highly charged ions from an ECRIS. The two most important effects are the mass effect and the dilution effect. Their relative weights have not been determined experimentally yet, but it is generally assumed that the mass effect is dominant in standard ECRIS installations with stainless steel plasma chambers. In order to gain more insight into the physics of the gas mixing effect and in particular on the relevance of the dilution process, we have carried out a study where we have investigated the role of the plasma-wall interaction on the gas mixing effect. In this contribution, we shall discuss Charge state distributions spectra, measured at the Frankfurt ECRIS using different working gases, pure argon, a mixture of argon and oxygen, and argon mixed with neon.     

压力式SF_6气体密度控制器生产及使用中应注意的几个问题

阐述了SF6气体的物理特性,定量分析了温度引起的表壳内压变化对仪表示值的影响,介绍了2种检漏方法的区别及漏率的计算,说明了仪表温度补偿机理、原则及使用环境条件对仪表正常工作的影响。     

Cooling of extraction electrode of an ion source in long-pulse operation

Experimental studies were made on the cooling of extraction electrodes of an ion source in the case of long-pulse operation. Copper electrodes with forced water cooling pipes were tested under the condition that an ion beam of 1 to 5 A at 30 keV was extracted for up to 10 s. The average heat loading to the grid are of the electrode was as high as 130 W/cm2. This high heat flux was obtained by a set of electrodes artificially arranged to produce poor beam optics, and hence the high heat loading. Temperature of the ground electrode was measured at two points by thermocouples buried and silver brazed in it, and was kept below 230 degrees C due to a large boiling heat transfer coefficient of the cooling water. No evidences of deformation or deterioration of the electrodes was observed after repetitious beam extraction. This heat loading was still a half of that on the grid of the ion source for the JT-60 NBI.     

大气压基体辅助激光解析离子源的研制及其与高分辨飞行时间质谱仪的联用

介绍了自制大气压基体辅助激光解析离子源的原理及结构.考察了该离子源与高分辨率垂直引入式飞行时间质谱仪联用后的性能.实验结果表明,仪器灵敏度、质量分辨率和精度等达到了较高水平.     

Gas discharge ion source III. Modified Berkeley multifilament ion source

Total ion current, ion energy, mass and current density distributions, and the impurity content of the ion beams produced by a modified Berkeley multifilament ion source (MFIS) were measured as a function of source configuration, gas pressure, and operating conditions: the 'best' configuration produced beams of 200 mA or more at pressures between 0.40 and 2.0 Pa. In comparison with earlier studies of duoplasmatron and duopigatron sources, the MFIS beams contained less D(+), only ca. 33%, but the beams had much narrower energy distributions and flatter current density distributions. The beams contained 1%-2% impurities which consisted mainly of masses 18, 20, and 22.     

正压法音速喷嘴标准装置气源系统设计

为提高正压法音速喷嘴标准装置压力和流量稳定性能,提出了正压法气源系统设计的方法,设计包括气源及压缩气体净化系统,以及气源稳压系统。针对空压机出口气体特点,净化系统采用水冷型后置冷却器、高效除油器、精密过滤器、冷干机及吸干机组合的方式,并合理选择净化系统各部分参数,使得压缩空气达到-65℃左右的压力露点。系统采用自力式调压阀与稳压罐实现稳压功能,并用各个参量评估系统压力、流量稳定性能指标。最后通过实验验证设计效果,结果表明在同一流量点,滞止压力稳定性可以保持在0.2%以内,流量控制在0.03%以内,可以满足气体流量的检定需求。     

Laser ion source with solenoid for Brookhaven National Laboratory-electron beam ion source

The electron beam ion source (EBIS) preinjector at Brookhaven National Laboratory (BNL) is a new heavy ion-preinjector for relativistic heavy ion collider (RHIC) and NASA Space Radiation Laboratory (NSRL). Laser ion source (LIS) is a primary ion source provider for the BNL-EBIS. LIS with solenoid at the plasma drift section can realize the low peak current (～100 μA) with high charge (～10 nC) which is the BNL-EBIS requirement. The gap between two solenoids does not cause serious plasma current decay, which helps us to make up the BNL-EBIS beamline.