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MAT高分辨气体同位素质谱计出现发射电流灯丝频繁烧断和灵敏度不稳定的故障,根据故障现象对相关单元电路的参数进行了检测,分析出仪器故障是由于电源高压不稳定和离子源污染引起的,通过对高压电路的清洁和离子源的清洗,最终排除了故障。 相似文献
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探伤加速器的剂量率稳定性是反映加速器整体性能的重要指标。剂量率的稳定涉及的因素较多,运行中磁控管与加速管频率的匹配是主要因素。通过磁控管的调谐机构,调整其频率以适应加速管的频率变化是稳定剂量率的一个重要手段。磁控管自动调谐机构采用步进电机驱动磁控管调谐旋钮,采用编码器纪录调谐旋钮的位置,通过位置估算磁控管的频率。 相似文献
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作为小型探伤电子直线加速器功率源的磁控管 (工作频率为 93 70MHz) ,其主要缺点是自身振荡频率的稳定性差 ,且磁控管在工作中由于各种原因会产生打火、跳谱和散谱现象 ,从而造成加速器工作不稳定 ,因此 ,必须采用频率稳定系统。为了更好地解决上述问题 ,应用BP神经网络方法 ,以保证工作频率稳定。 相似文献
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采用磁控管做功率源的低能电子直线加速器在医疗、辐照、X射线检测等领域得到较为广泛的应用。磁控管产生的微波信号输入到加速管,对电子束进行加速,磁控管的工作频率稳定性对加速器电子束能量、能散及发射度产生直接的影响。但磁控管是一种振荡器,其频率受到温度、振动、负载牵引的影响会产生漂移,所以需要一套自动频率控制系统(Automatic Frequency Control,AFC)机构对磁控管进行频率控制。目前普遍采用的AFC机构主要是行波控相或双腔鉴频,对两路检波信号差分放大进而控制伺服电机进行调谐的方法实现磁控管的频率稳定。随着数字化I/Q和FPGA(Field-Programmable Gate Array)技术的不断发展,运用该技术进行磁控管的频率控制完全具备可行性。本文从理论和工程设计上阐述了数字化I/Q技术在磁控管频率控制上的应用。 相似文献
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文章介绍西德DESY研究所750keV负氢离子预注入器的调整结果。通过提高弧流,磁控管型H~-离子源可以引出18keV,60—80mA的H~-脉冲离子流。发现外部磁场可以在螺旋管内部感生一个方向大体相同的磁场。在低能输运段,离子束空间电荷中和所需的时间约100μs。在离子源引出束流约65mA时,经两对螺旋管聚焦和RFQ加速后可以获得能量为750±8.8keV,聚团半宽度约0.8ns,发射度约3mm·mrad,束流为52mA的脉冲H~-流;其中33mA以上的束流处于1mm·mrad以内。 相似文献
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强流离子源是EAST(Experimental Advanced Superconducting Tokamak)中性束注入器(Neutral Beam Injector,NBI)最关键的核心部件,其能达到的性能在很大程度上决定了EAST中性束注入器所能达到的指标。离子源在束引出时电极打火现象偶有发生,这对于离子源的正常运行有非常严重的影响,甚至危害离子源的寿命。本文结合离子源运行过程中的束引出实验波形和水流量热计(Water Flow Calorimetry,WFC)系统的测量数据得出等离子体发射面的束流光学系统一直处于非最佳聚焦状态是导致打火的原因,试通过优化高压投入时刻等离子体与高压的匹配,实现高压的稳定投入有效抑制打火现象的发生,并且给离子源加入硬件保护机制,为离子源安全稳定运行奠定基础。 相似文献
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The Power Supply System of Ion Source for NBI 总被引:4,自引:0,他引:4
The power supply system of ion source for the Neutral Beam Injector (NBI) in the HT-7 superconducting tokamak is based on a single injector with one ion source that can deliver 700 kW of neutral beam power. Experiments and a discharges test on the ion source were successfully performed. In this paper, the circuit structures and features of every power supply are described and the results of the discharges test are presented. 相似文献
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To reveal the argon plasma characteristics within the entire region of an electron cyclotron resonance(ECR) ion source, the plasma parameters were diagnosed using a bended Langmuir probe with the filament axis perpendicular to the diagnosing plane. Experiments indicate that,with a gas volume flow rate and incident microwave power of 4 sccm and 8.8 W, respectively,the gas was ionized to form plasma with a luminous ring. When the incident microwave power was above 27 W, the luminous ring was converted to a bright column, the dark area near its axis was narrowed, and the microwave power absorbing efficiency was increased. This indicates that there was a mode transition phenomenon in this ECR ion source when the microwave power increased. The diagnosis shows that, at an incident microwave power of 17.4 W, the diagnosed electron temperature and ion density were below 8 eV and 3?×?10~(17) m~(-3), respectively, while at incident microwave power levels of 30 W and 40 W, the maximum electron temperature and ion density were above 11 eV and 6.8?×?10~(17) m~(-3), respectively. Confined by magnetic mirrors, the higher density plasma region had a bow shape, which coincided with the magnetic field lines but deviated from the ECR layer. 相似文献
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An experiment system of ceramic-cup microwave ion source has been built here,Its microwave absorption efficiency as a function of the magnetic field and the pressure is presented ,When the microwave incident power is 300-500W the microwave absorption efficiencies are more than 90% if the system is optimized and the magnetic field at the microwave widows is 0.095T. 相似文献
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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. 相似文献
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针对典型的大功率整流电源,提出了一种基于数字控制的设计方案。通过对大功率中性束注入器离子源灯丝电源的方案设计和实验结果,验证了数字控制方案的可行性与优越性。由于数字控制方案的应用,使得灯丝电源的设计更加智能化和简单化,为相关的应用场合提供了参考。 相似文献
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Zhimin Liu Sheng Liu Caichao Jiang Yahong Xie Chundong Hu 《Journal of Fusion Energy》2014,33(4):398-405
A neutral beam injector (NBI) test stand was constructed to develop a multi-megawatt prototype ion source as an auxiliary heating system on experimental advanced superconducting tokamak. A power supply system for the NBI test stand components such as a set of dc power supplies for plasma generator, a dc high voltage power supply of a tetrode accelerator, a transmission line and a surge energy suppressor. Stable arc discharges of the plasma generator with hydrogen gases for 100 s long pulse have been produced by six Langmuir probes feedback loop regulation mode to control the arc power supply. The 4 MW hydrogen ion beam of 1 s is extracted with beam energy of 80 keV and the beam current of 52 A. The dc high voltage power supply for the plasma grid of the prototype ion source was designed to contribute maximum voltage of 100 kV and current of 100 A. The high voltage power output is continuously adjustable to satisfy with plasma physics experiment in operation frequency of 10 Hz. To prevent damage of the beam source at high voltage breakdown, core snubber using deltamax soft magnetic materials have been adopted to satisfy the input energy into the accelerator from the power supply can be reduced to about 5 J in the case of breakdown at 80 kV. For the transmission line, a disc shape multi cable coaxial configuration was adopted and which the dimension of the diameter is 140 mm at the core snubber. The major issues of discharge characteristics with long pulse and beam extraction with high power for the prototype ion source were investigated on the NBI test stand. 相似文献