SFC轴向注入线上的线性聚束器

ＳＦＣ轴向注入线采用了一个双间隙漂移管式聚束器和一个单间隙栅网型聚束器,分别采用三角波和锯齿波的聚束波形。采用充放电式的高频电压发生器可以得到要求的聚束电压。     

Gas flow and related beam losses in the ITER neutral beam injector

The gas flow in the ITER neutral beam injectors has been studied using a 3D Monte Carlo code to define a number of key parameters affecting the design and operation of the injector. This paper presents the results of calculations of the gas density in the two accelerator concepts presently considered as options for the ITER injectors, and the resultant stripping losses of the negative ions during their acceleration to 1 MeV. The sensitivity of the model to various parameters has been studied, including the gas temperature in the ion source and the subsequent accommodation by collisions with the accelerator structure, and the degree of dissociation of the D₂ or H₂ in the ion source, and subsequent recombination during collisions with the accelerator structure. Additionally the sensitivity of the losses to details of the beam source design and operating parameters are examined for both accelerator concepts.     

EAST中性束注入器研制进展

EAST(Experimental Advanced Superconducting Tokamak)作为世界上第一个全超导非圆截面托克马克,其目标是研究1 000 s的长脉冲稳态运行的前沿性物理问题,要达成这一目标,必须有高功率电流驱动和辅助加热系统以实现EAST装置的高参数稳态运行。中性束注入(Neutral Beam Injection,NBI)加热是等离子体辅助加热和维持最有效的手段之一,为此一套注入功率4–8 MW、脉冲宽度10–100 s的中性束注入系统于2010年开工建设,并于2014年实现了对等离子体的加热和驱动。本文主要展示了EAST中性束注入器的最新进展,从长脉冲束引出和高功率束引出两个方面介绍了EAST中性束注入器综合测试台的最新实验结果,结果表明在束功率和脉冲宽度方面已经达到或超过设计指标。     

SFEL高亮度注入器的设计和粒子动力学特性

使用国际通用程序ＥＴＰ，ＰＡＲＭＥＬＡ和自编程序ＰＬＳ－ＩＭ－６０等对高亮度注入器作了详细的优化设计和粒子动力学数值模拟，注入器出口的电子束品质的主要参数为：能量３．５ＭｅＶ，能散２％（６２％电子）微脉冲束团相宽～４ｐｓ（６２％电子）在第一根加速管出口的电子品质的主要参数为：能量３３ＭｅＶ，能散０．３％（６２％电子）微脉冲峰值电流～８０Ａ，束团相宽３ｐｓ（６２％电子）束归一化发射度２０－３０πｍｍ     

Dose rates from the induced activity in the ETF neutral beam injector

The dose equivalent rates outside the Engineering Test Facility neutral beam injector shield from the induced radioactivity have been calculated for the reactor operating at 1140 MW for 1, 30, and 365 days. The dose rates at one day after shutdown are large even after one day of operation. Depending on the location and operating time, cooling times from 30 days to 5 years are required before the dose rates are sufficiently low to allow routine maintenance work in the vicinity of the NBI shield.     

大功率NBI系统的PLC时序控制应用

论述了利用PLC逻辑关系对放电实验控制运行的工作原理,介绍了PLC梯形图应用程序和VB6.0环境下上位机监控程序的开发以及良好的人机操作界面,通过上位机监控界面来实时监控各电源及设备的运行状态.PLC控制系统的应用保障了实验装置的安全运行,极大地方便了实验中对放电参数的改变和设置.     

Optimization of the gas flow in the neutralization region of EAST neutral beam injector

According to the problems encountered in the experiments of the EAST neutral beam test stand, the design of neutralizer of EAST neutral beam injector is suggested to modify to optimize the gas flow in the neutralization region. The modifications contain narrowing the slits between the neutralizer and the mounting flange hole, and rotating the gas injection angle from 90° to 60° in the neutralizer. In this paper, an adjusted Direct Simulation Monte Carlo (DSMC) code was used to estimate the modification. The results show that a little change of the slits width causes a large variation of gas target thickness, and the rotation of the gas injection angle can effectively reduce the gas density near the accelerator but with a little of decrease of target thickness.     

The influence of neutral beam optimization for DEMO on injector design

The requirements for neutral beam injection (NBI) on DEMO are assessed and the consequences for the design of the injectors discussed. Optimization of current drive requires NBI within a 2 m × 2 m envelope at large tangency radii. This is compatible with beamlines of 20 m length and moderate high voltage stand-off distances between injectors. However, q-profile control will necessitate at least three beamlines of different injector types and may not be compatible with shinethrough. Material irradiation studies show that, with three exceptions, there is no significant design issue for distances greater than 3 m from the tokamak wall.     

扇聚焦等时性回旋加速器性能的改进和提高

安装了ＥＣＲ离子源及其外注入系统后，增加了离子种类、提高了束流强度。扇聚焦等时性回旋加速器（ＳＦＣ）主要工作点分布于三次谐波加速区域，为了匹配外注入系统，仔细地研究了中心区，重新设计加工了Ｄ盒及假Ｄ。为了改进ＳＦＣ性能，提高运行效率，同时进行了其它改进工作。介绍了改进后的ＳＦＣ的调束工作。     

离子束混合提高耐热钢抗高温氧化性能研究

耐热钢4Cr9Si2试样上溅射沉积60nm左右的Si_3N_4或Si薄层,然后用120keV的N_2~+或Ar~+束轰击。氧化动力学曲线测量及扫描电镜观察表明,离子束混合使耐热钢的抗高温氧化性能有明显的提高。离子束混合同时也延长了汽车车灯玻璃耐热钢成型模具的使用寿命。并用TEM,AES,XPS及Monte-Carlo模拟法进行了分析。     

Criticality in the fabrication of ion extraction system for SST-1 neutral beam injector

For the heating of plasma in steady-state superconducting tokamak (SST-1) (Y.C. Saxena, SST-1 Team, Present status of the SST-1 project, Nucl. Fusion 40 (2000) 1069–1082; D. Bora, SST-1 Team, Test results on systems developed for the SST-1 tokamak, Nucl. Fusion 43 (2003) 1748–1758), a neutral beam injector is provided to raise the ion temperature to 1 keV. This injector has a capability of injecting hydrogen beam with the power of 0.5 MW at 30 keV. For the upgrade of SST-1, power of 1.7 MW at 55 KeV is required. Further, beam power is to be provided for a pulse length of 1000S. We have designed a neutral beam injector (S.K. Mattoo, A.K. Chakraborty, U.K. Baruah, P.K. Jayakumar, M. Bandyopadhyay, N. Bisai, Ch. Chakrapani, M.R. Jana, R. Onali, V. Prahlad, P.J. Patel, G.B. Patel, B. Prajapati, N.V.M. Rao, S. Rambabu, C. Rotti, S.K. Sharma, S. Shah, V. Sharma, M.J. Singh, Engineering design of the steady-state neutral beam injector for SST-1, Fusion Eng. Des. 56 (2001) 685–691; A.K. Chakraborty, N. Bisai, M.R. Jana, P.K. Jayakumar, U.K. Baruah, P.J. Patel, K. Rajasekar, S.K. Mattoo, Neutral beam injector for steady-state superconducting tokamak, Fusion Technol. (1996) 657–660; P.K. Jayakumar, M.R. Jana, N. Bisai, M. Bajpai, N.P. Singh, U.K. Baruah, A.K. Chakraborty, M. Bandyopadhyay, C. Chrakrapani, D. Patel, G.B. Patel, P. Patel, V. Prahlad, N.V.M. Rao, C. Rotti, V. Sreedhar, S.K. Mattoo, Engineering issues of a 1000S neutral beam ion source, Fusion Technol. 1 (1998) 419–422) satisfying the requirements for both SST-1 and its upgrade. Since intense power is to be transported to SST-1 situated at a distance of several meters from the ion source, the optical quality of the beam becomes a primary concern. This in turn, is determined by the uniformity of the ion source plasma and the extractor geometry. To obtain the desired optical quality of the beam, stringent tolerances are to be met during the fabrication of ion extractor system.

SST-1 neutral beam injector is based on positive ion source. The extraction system consists of three grids, each having extraction area of (width) 230 mm × (height) 480 mm and 774-shaped apertures of 8-mm diameter. To obtain horizontal focal length of 5.4 m and vertical of 7 m, each grid consists of two halves with 387 apertures. Two halves are inclined at an angle of 1.07 ± 0.01°. For long pulse operation, active water cooling is provided by in-laid down of dense network of 22 wavy semicircular (r = 1.1 ± 0.05 mm) cooling channels in the space available between the apertures. The required flatness of the copper plate is 100 μm and positioning tolerance of aperture is ±60 μm. The measurement obtained after fabrication is compared with the specifications. It is pointed out that fabrication within set tolerance limit could be achieved only through process of fabrication and high-resolution measurements.     

EAST中性束注入器水流热量累积测量系统误差分析

水流量热法是强流离子束束功率测量常用的方法,由于测量仪表安装位置的问题,EAST(Experimental Advanced Superconducting Tokamak)全超导托卡马克中性束注入水流热量累积测量系统中存在不可忽略的误差。本文结合水流热量累计测量系统的原理分析其误差的来源,针对其中由于采集时间有限和真空室内外热传递损失三部分误差来源进行了详细的分析和修正,将沉积功率百分比由73.72%提高到86.27%,修正结果显著。最终将修正方法嵌入到现有的沉积功率计算系统中,实时地进行误差修正,从而得到更精确的沉积在热承载部件上的功率沉积,为功率沉积分布和中性化效率的精确测量提供依据。     

Progress in development and design of the neutral beam injector for JT-60SA

Neutral beam (NB) injectors for JT-60 Super Advanced (JT-60SA) have been designed and developed. Twelve positive-ion-based and one negative-ion-based NB injectors are allocated to inject 30 MW D⁰ beams in total for 100 s. Each of the positive-ion-based NB injector is designed to inject 1.7 MW for 100 s at 85 keV. A part of the power supplies and magnetic shield utilized on JT-60U are upgraded and reused on JT-60SA. To realize the negative-ion-based NB injector for JT-60SA where the injection of 500 keV, 10 MW D⁰ beams for 100 s is required, R&Ds of the negative ion source have been carried out. High-energy negative ion beams of 490–500 keV have been successfully produced at a beam current of 1–2.8 A through 20% of the total ion extraction area, by improving voltage holding capability of the ion source. This is the first demonstration of a high-current negative ion acceleration of >1 A to 500 keV. The design of the power supplies and the beamline is also in progress. The procurement of the acceleration power supply starts in 2010.     

Design study of a 120-keV,3He neutral beam injector

We describe a design for a 120-keV, 2.3-MW,³He neutral beam injector for use on a D-³He fusion reactor. The constraint that limits operating life when injecting He is its high sputtering rate. The sputtering is partly controlled by using an extra grid to prevent ion flow from the neutralizer duct to the electron suppressor grid, but a tradeoff between beam current and operating life is still required. Hollow grid wires functioning as mercury heat pipes cool the grid and enable steady state operation. Voltage holding and radiation effects on the acceleration grid structure are discussed. We also briefly describe the vacuum system and analyze use of a direct energy converter to recapture energy from unneutralized ions exiting the neutralizer. Of crucial importance to the technical feasibility of the³He-burning reactor are the injector efficiency and cost; these are 53% and $5.5 million, respectively, when power supplies are included.The beam is composed of 91 separate, parallel currents that flow in the gaps between the elements or wires of a grid. Each such flow is referred to as a beamlet. The current densities in Figs. 5, 8, and 9 are values within a beamlet, as measured at the beam-forming grid. They are not values averaged over the entire beam cross-section.     

EAST中性束注入器稳态偏转磁铁的参数设计与估算研究

中性束注入器偏转磁铁是剥离束流中剩余离子的关键设备,它与剩余离子吞食器等内部部件构成了中性束注入器的束偏转系统。束偏转系统的性能对中性束注入器束流的品质及其束传输效率发挥着重要作用。本文根据EAST(Experimental Advanced Superconducting Tokamak,EAST)中性束注入器对束偏转系统的要求,对其偏转磁铁各性能参数进行了估算。为中性束注入器设计了一台用以剩余离子180°偏转的偏转磁铁。该偏转磁铁采用H型二极电磁铁结构;其磁极端面设计为138cm×47cm的圆角矩形结构;其线圈设计为每侧2饼,每饼2层,每层8根的串联结构,导线选用外方内圆空心铜导体,以满足偏转磁铁稳态运行的需要。该设计的偏转磁铁在370 A励磁电流条件下,可提供80keV氘离子束偏转所需的磁场。实验测试结果显示:500 A励磁电流稳态运行条件下,偏转磁铁线圈冷却水温升约21.5℃,该设计结构的偏转磁铁满足EAST中性束注入器满参数稳态运行和未来运行参数逐步提高的需要。     

EAST-NBI离子源电极打火分析及处理

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。     

Achievement of 1000 s plasma generation of RF source for neutral beam injector

A radio frequency(RF) ion source was developed for neutral beam injector in Institute of Plasma Physics, Chinese Academy of Sciences(ASIPP). A cylindrical driver based RF plasma source was tested and optimized for long pulse operation. Recently, the plasma source achieved 1000 s stable plasma discharge with RF power of 35 k W and source pressure of 0.7 Pa for the first time.The heat loading on each of driver components such as the Faraday shield(FS), RF coil and expansion chamber was measured by the water flow calorimeter system. The experiment results showed that FS is the component with highest heat loading and the heat loading on FS was about 65.8% of total heat loading on source. The details of the long pulse operation of RF plasma source are presented in this paper.     

Design of the reflection magnet and its shielding effect analysis for the neutral beam injector of EAST

In this paper,a reflection magnet to be installed in the EAST neutral beam injection system is simulated and designed.The field intensity of reflection magnet of 42-cm maximum bending radius is about 1.539×10-1 T for 100 keV deuterium beam.The shielding cage is formed by rods.Using the ANSOFT software,the magnetic shielding effect was estimated at about 3% at the magnet pole region.     

A beam optics study of the biomedical beam line at a proton therapy facility

A biomedical beam line has been designed for the experimental area of a proton therapy facility to deliver mm to sub-mm size beams in the energy range of 20-50 MeV using the TRANSPORT/TURTLE beam optics codes and a newly-written program. The proton therapy facility is equipped with a 230 MeV fixed-energy cyclotron and an energy selection system based on a degrader and slits, so that beam currents available for therapy decrease at lower energies in the therapeutic beam energy range of 70-230 MeV. The new beam line system is composed of an energy-degrader, two slits, and three quadrupole magnets. The minimum beam sizes achievable at the focal point are estimated for the two energies of 50 and 20 MeV. The focused FWHM beam size is approximately 0.3 mm with an expected beam current of 20 pA when the beam energy is reduced to 50 MeV from 100 MeV, and roughly 0.8 mm with a current of 10 pA for a 20 MeV beam.