HL-1M装置边缘扰动和流速的实验研究

利用一组马赫探针研究HL-1M装置刮离层和边缘等离子体流在欧姆放电、壁硼化、偏压抽气孔栏、偏压电极、低混杂波电流驱动、电子回旋共振加热、弹丸注入、分子束注入、激光吹气和补充送气等情况下的平行流马赫数、离子饱和电流扰动、平行流速度剪切和极向流速度的分布。实验中发现局部等离子体电位快速变化，改变了电场分布，改变了边缘等离子体的流速和方向。从而改善了等离子体约束性能。     

HL-2A装置中性束注入器高抽速钛泵及其实验运行分析

针对中性束注入等离子体加热过程中的高真空条件要求,借助于国际合作方式,我们为HL-2A 装置中性束注入器设计了一种大吸附面积的高抽速钛泵系统.钛泵系统抽速设计值为30万L/s,由两台大泵和一台小泵组成,两台大钛泵分别置于注入器主真空室左右两侧,小钛泵置于注入器副真空室右侧.运行实验结果表明,钛泵完全满足HL-2A中性束注入实验的要求.本文主要介绍了钛泵的工程设计和实验运行结果,简要分析了HL-2A装置中性束加热系统高抽速钛泵的运行特点.     

HL-1M装置氦辉光放电清洗的实验研究

氦辉光放电清洗 (GDC(He) )是HL - 1M (环流器新一号 )托卡马克装置控制C、O杂质、壁H再循环和改善真空壁条件的有效方法。它与泰勒放电清洗 (TDC)、交流放电清洗 (AC)、电子回旋共振放电清洗 (ECR)相比 ,设备简单、不需要磁场且操作安全 ;与烘烤去气相比 ,它对环形真空室壁的去气率高 ,本底杂质浓度低。分别描述了去O、去C和去H的清洗模式 ,并提出了控制壁H再循环和壁清洁度的清洗指标     

中国环流三号（HL-3）壁处理系统研制

托卡马克装置壁处理系统对获得高真空、洁净的器壁条件至关重要。介绍了中国环流三号(HL-3)装置真空系统中的壁处理各子系统设计及研制概况。分析了壁处理系统调试运行过程和特点,设计了烘烤系统和直流辉光清洗系统的运行方案。分别对烘烤系统、直流辉光清洗系统以及射频辅助直流辉光放电系统的首次运行结果进行了讨论。通过应用壁处理系统,配合真空抽气系统,HL-3装置真空系统运行达到预期目标,初始放电前装置最小压力达到2.4×10^-6 Pa。     

中性束系统大抽速低温泵的初步设计

HL-2A装置即将开展改造和升级,升级后的HL-2M将在中后期开展近10 MW的中性束实验.随着中性束系统功率和脉冲宽度的增加,常规的真空抽气系统将不能满足要求,需要开展大抽速洁净真空获得技术的研究.在大量调研的基础上,结合作者在德国IPP的工作经验,初步设计了用于HL-2M装置的4 MW束线的大抽速低温泵.本文阐述了用于中性柬柬线的低温泵的工作原理和基本结构,针对HL-2M中性束真空系统的需求进行了设计和计算,并对结构上面临的主要技术难点进行了分析和说明.     

低温技术在受控核聚变实验中的应用

在中国环流器一号（ＨＬ－１）等离子体物理实验中，增加了弹丸注入和电子回旋共振加热系统。对低温技术在其中的应用情况，液氦输送系统，输液方法及氦气回收系统做了介绍。在一次等离子体物理实验中，总共使用液氦２７３３Ｌ。在弹丸注入系统中，使装置的等离子体密度提高了１～２倍。在装置上成功地实现了电子回旋共振加热，使等离子体电子温度增加３０％以上。     

HL—1M装置边缘把动和流速的实验研究

利用一组马赫探针研究ＨＬ－１Ｍ装置刮离层和边缘等离子体流在欧姆放电，壁硼化，偏压抽气孔栏，偏压电极，低混杂波电流驱动，电子回旋共振加热，弹丸注入，分子束注入，激光吹气和补充送气等情况下的平行流马赫数，离子饱和直流扰动，平行流速度剪切和极向流速度的分布。实验中发现局部等离子体电位快速变化，改变了电场分布，改变了边缘等离子体的流速和方向。     

HL—1M装置真空壁硅化的研究

CDC（He SiH4)是为HL－1M装置研制的一种常规壁处理技术。在He辉光等离子体作用下,通过气相中的电子碰撞离解,电离,离子－分子反应和在壁面上的He^ 诱导脱H2过程,一种无定形的,半透明的,致密的氢化硅（α-Si:H)薄膜被沉积在清洁的真空壁表面。在托卡马克放电中,硅化壁的特点是有良好的H（D）捕获得,H2（D2）释放和低再循环性能,强的控制杂质能力和较长的寿命时间,结果显著地拓宽了等离子体密度ne,持续时间Tp和能量约束时间τE等的运行范围。自1996年以来,它成功地演证LHCD,ICRH,ECRH,NBI,PI,MBI实验和升级等离子体运行提供了良好的真空壁条件,并取得了丰硕的物理实验和工程技术的研究成果。同时还为利用中型装置在长脉冲放电条件下,开展等离子体与表面互相作用（PSI)提供了一条新的途径,本文主要描述HL－1M装置的Si化关系,参数和放电进展。     

HL-2A装置硅化镀膜壁处理控制杂质行为研究

硅化壁处理能有效控制等离子体杂质和再循环水平,是HL-2A装置的常规壁处理手段。介绍了HL-2A装置的硅化壁处理系统以及硅化镀膜壁处理控制杂质行为的主要研究进展。HL-2A装置硅化壁处理系统包括离线硅化和在线硅化壁处理系统,分别采用辉光放电辅助沉积以及等离子体放电辅助沉积进行硅化镀膜壁处理。实验结果表明,离线硅化壁处理后氧杂质明显降低,但随着实验进行会逐渐增加,硅化镀膜寿命约150炮。为进一步开展研究,HL-2A采用了在线硅化壁处理技术,研究发现在线硅化壁处理过程中碳、氧、铁等杂质均有所减少。两种硅化方式下真空室内的H₂O、CO含量均明显降低,在线硅化壁处理耗气量远少于离线硅化。通过硅化壁处理,有效地提升了HL-2A等离子体性能,也为未来聚变装置稳态运行器壁的处理提供了重要技术参考。     

HL-1M装置器壁锻炼

HL-1M装置运行的7年中，系统地研究了器壁原位清洗、原位硼化、硅化、锂化和锂-硅复合处理以及涂层的原位清除技术。由于原位硅化具有稳定、良好的杂质和再循环控制能力，使其成为HL-1M装置进行改善等离子体约束实验必不可少的壁处理手段。锂-硅复合壁具有锂壁的低杂质、低氢再循环和低辐射能量，又具有硅化壁长寿命的特点，是目前最佳的壁处理手段。He-GDC取代了H2-TDC，在器壁原位清洗、器壁原位处理和涂层原位清除中扮演了重要角色。     

Ion induced gas desorption problems in the ISR

Not least among the many stringent conditions which must be satisfied to achieve the proper operation of the Intersecting Storage Rings at CERN are those pertaining to its 2 km of ultrahigh vacuum. Apart from the direct influence of the residual gas molecules through nuclear and Coulomb scattering on the stored beam lifetimes (of the order of days during which the stored protons should travel the astronomical distance of some light days!) there are also indirect processes which additionally involve adsorption/desorption phenomena on the vacuum chamber wall. The beam of high energy protons creates low energy secondary ions in the residual gas. These ions, generated in the space charge potential of 1 kV (10 A)^?1 of proton beam, are accelerated by this potential onto the stainless steel vacuum chamber wall where a variety of adsorption/desorption phenomena may be stimulated. Desorbed molecules are fed back into the residual gas resulting in the possibility of creating an unstable run-away pressure increase which can finally destroy the stored beam. This danger depends on the local parameters of the vacuum system, and most critically, on the state of the vacuum chamber surface.The paper summarises recent observations in this field and describes the results of investigations aimed at producing cleaner surfaces in vacuum chambers. These investigations, which have included high temperature bakeouts, ion bombardment scrubbing by glow discharge, oxidation, etc, will show that under favourable conditions, net negative desorption coefficients can be obtained which turn the Intersecting Storage Rings into a large ion pump. Results, supported and compared with measurements using Auger and Sims surface analysis, are presented mainly from the empirical point of view with the emphasis on practical implications for machines where the surfaces of the vacuum system are subjected to ion bombardment.     

3D-Druck für Hochvakuumanwendungen

3D-Printing for High Vacuum Applications 3D printing technology has made the leap from a home-based private practice to industrial manufacturing. Due to the increasing reliability of printers and increasing material diversity, especially in the metal sector, double-digit percentage growth rates are possible in the coming years. This thesis deals with the manufacture of parts made by 3D printing for high vacuum application. Different components are printed and examined for their vacuum compatibility. As shown furthermore, conventionally made standard components can be vacuum sealed to printed parts, which enables cost-effective production of more complex components, such as e.g. a vacuum chamber allows. In addition, functional components can already be realized in the manufacturing process. The integration of a system of flow channels directly into the wall of a chamber is just one example. Thus, such a chamber can be heated during evacuation and effectively cool in later operation.     

Reduction of hydrogen and helium retention in stainless steel by argon glow discharge

Although wall conditioning using Ar glow discharges is occasionally employed to reduce helium and hydrogen retention in the inner walls of the vacuum chamber of nuclear fusion devices, the effect of an Ar glow discharge on the reduction of helium and hydrogen retention has never been systematically investigated. In the present experiment, Ar glow discharges were applied to the stainless steel walls of a glow discharge device. Residual gas analysis (RGA) clearly showed that the Ar glow discharge significantly reduced the amount of helium and hydrogen retained. It was found that the fraction of the amount of desorbed helium to the initial retained amount of helium was as high as 13% and the fraction of the amount of desorbed hydrogen to the initial amount of hydrogen was as high as 36%.     

3D-Druck für Hochvakuumanwendungen

To mark our anniversary, we are presenting articles that have been particularly appreciated by readers of our online edition once again in print. Here: 3D-Printing for High Vacuum Applications 3D printing technology has made the leap from a home-based private practice to industrial manufacturing. Due to the increasing reliability of printers and increasing material diversity, especially in the metal sector, double-digit percentage growth rates are possible in the coming years. This thesis deals with the manufacture of parts made by 3D printing for high vacuum application. Different components are printed and examined for their vacuum compatibility. As shown furthermore, conventionally made standard components can be vacuum sealed to printed parts, which enables cost-effective production of more complex components, such as e.g. a vacuum chamber allows. In addition, functional components can already be realized in the manufacturing process. The integration of a system of flow channels directly into the wall of a chamber is just one example. Thus, such a chamber can be heated during evacuation and effectively cool in later operation.     

Influence of electromagnetic confinement on the characteristics of a triode magnetron sputtering system

Three different configurations of magnetic traps were set up by changing the number of central magnets in a Triode Magnetron Sputtering system, where the anode consists of a grid positioned at a distance from an aluminum target on the cathode. The grid and the wall chamber are grounded and the plasma is formed in the space between the target and the grid. The current-voltage (I-V) characteristics of argon discharges were obtained, for each magnetic configuration and for various grid-target distances. It is noticed that the magnetron efficiency strongly depends on the inter-electrode distance and magnetic trap configuration. The configuration with the highest unbalance coefficient has I-V curves that differ substantially from the usual relation observed in conventional magnetron discharges. In this case the usual I-V fitting curves of magnetron mode of operation are not appropriate to describe the electrical characteristics of the discharge.     

低温真空腔体结构设计及传热分析

为适应未来航天低温光学系统的需要,研制了1套测量光学元件低温场和低温变形的系统。该系统由真空机组、低温真空腔体、防振系统、测量装置等主要部分组成。其中低温真空腔体是该系统中关键的装置,为光学元件的低温真空实验提供了必要的条件。对低温真空腔体的结构设计、真空度和传热进行了分析探讨,并且对梯形薄壁绝热支撑进行了详细结构热分析和COSMOSWORK软件的传热分析,结果表明可以满足低温真空的实验要求。     

Ten years of ELETTRA vacuum system experience

In 2003 ELETTRA celebrates 10 years since the first beam accumulation. Its vacuum system was designed to maintain a pressure lower than 5×10⁻⁹ mbar during machine operation, because UHV conditions are necessary to reduce the gas bremsstrahlung and the elastic Coulomb gas scattering in order to obtain a long beam lifetime. The evolution of the vacuum system and the performance of its components will be summarised. Moreover, the main vacuum malfunctions and their impact on accelerator operation will be described in detail. In particular, welded bellows, ageing of the vacuum control system, and human mishandling were identified as the most common causes of the vacuum system failures. In order to obtain a more reliable and efficient vacuum system, some changes were made to the maintenance procedures, the recovery strategies after vacuum faults, the design of some vacuum components and the pumping strategies. The experience in managing the ELETTRA vacuum system will be discussed.     

冻干机用捕水器结霜特性研究中存在的问题

真空冷冻干燥过程中，从物料中升华出来的水分在真空泵的抽吸作用下，不断地在捕水器（也即冷阱）表面结霜，随着霜在捕水器表面不断凝结，致使其捕水效率不断降低，对真空系统形成不利的影响。但目前，对于低温、低压下的结霜机理研究极少，本文介绍了国内外有关低温冷壁面结霜的研究现状，并分析研究了真空冷冻干燥系统中冷壁面结霜过程中存在的问题。     

13 years’ operational experience of SPring-8 vacuum system

The first electron beam was stored in SPring-8 storage ring in March 1997. An overview of the 13 years’ operational experience concerning the vacuum system of the SPring-8 storage ring is presented. The evolution of the vacuum system and their performance are summarized. Moreover, the main vacuum failures and their impact on accelerator operation are described in detail. We analyze the relationship between the difference types of vacuum failure and downtime of user experiment.