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-1M装置的真空运行与质谱诊断

通过对 HL- 1M装置真空运行模式、真空运行参数、氦辉光放电清洗和硅化壁处理手段等的规范化 ,显著地改善了装置的真空壁出气、本底杂质浓度、托卡马克放电杂质出气比和再循环 ,成功地实现了高参数放电、长脉冲放电和装置暴露大气后快速恢复放电 ,并成功地为演证低混杂电流驱动、离子回旋共振加热、电子回旋共振加热、中性束注入、弹丸注入和分子束注入实验和升级等离子体运行等提供了良好的真空壁条件。描述了 HL- 1M装置真空系统、壁出气和再循环控制、质谱诊断和程序脉冲送气等方面的主要实验成果 ,并为 HL- 2 A装置的真空系统研制和运行提供了有益的参考     

HL—1M装置的八发弹丸注入系统及工程实验

八发弹丸注入系统自１９９６年投入ＨＬ－１Ｍ（中国环流器新一号）托卡马克加料实验并成功实现Ｈ２弹丸的八发连续注入等离子体。描述了此系统及其在液氮和液氦条件下分别以ＣＨ４和Ｈ２为丸料气的工程实验。压力高于５ＭＰａ的Ｈｅ为推进剂,弹丸速度达８００－１０００ｍ／ｓ。     

中国环流器新一号取得初步实验结果

中国环流器新一号装置（ＨＬ１Ｍ）是用于受控热核聚变实验研究的中型托卡马克装置，是在中国环流器一号（ＨＬ１）的基础上改建而成的，其主要物理目标是高功率辅助加热、低杂波电流驱动和弹丸注入加料，研究在这些条件下的高温等离子体性质。ＨＬ１Ｍ在１９９４年建成，１９９５年进入物理实验阶段。ＨＬ１Ｍ的正常运行为受控核聚变实验研究提供了很好的装置条件，几年来不断取得新成果。例如：低杂波工程系统的输出功率达到８５０ｋＷ，脉冲宽度１ｓ（超过设计值）；１９９８年首次进行了高能中性（氢）粒子注入即获成功；进行…     

HL—1M装置注入和加热实验的流速与电场测量

利用马赫－郎缪尔探针组研究了ＨＬ－１Ｍ装置刮离层和边缘等离子体流在欧姆放电、中性束注入、低杂波注入、离子回旋加热和电子回旋加热等情况下的极向流速、径向电场和极向电场的变化与分布,研究并讨论了它们对降低边缘粒子径向传输和改善等离子体约束性能的影响。     

电子回旋共振波等离子体及其应用

电子回旋共振波等离子体是依靠特殊的电磁波与电学各向异性材料相互作用来实现的,它被证明是一种适用于改进传统真空镀膜工艺的高效技术。与传统辉光等离子体放电系统相比,电子回旋共振波系统的特点是产生高离子电流密度、能量分布集中的等离子体,能够实现半导体薄膜的低压高速沉积,具有离化率高、放电反应室内无电极、适合大面积薄膜沉积等优点。在实际实验及应用中常使用双电源驱动等离子体放电系统,利用电子回旋共振波原理进行等离子体放电,而使用另一个独立的射频(或者直流)电源系统来驱动等离子体束流的引出,在等离子体放电过程中可实现独立、精确控制离子电流密度和离子能量等参数,在半导体薄膜沉积、精密刻蚀、等离子体源等领域有着重要的应用。本文主要介绍了电子回旋共振波等离子体原理、特点,并结合实验与诊断方法朗缪尔探针等技术来展示其研究应用进展。     

弹丸生成的物理模型和生成时间估算

弹丸注入是聚变工程和实验中研究等离子体加料、控制等离子体密度和杂质的重要手段。介绍了弹丸在低温恒温器冷凝腔中生成的物理模型，并由此估算了弹丸的生成时间，对弹丸实际制造、注入器实验调试起了重要的指导作用     

用等离子体源离子注入法提高金属表面耐蚀性

对等离子体源离子注入和常规离子注入进行了对比，介绍了等离子体注入在提高金属表面硬度和抗腐蚀性能上的应用，讨论了电子回旋共振等离子体源离子注入在提高表面腐蚀抗力中的前景。     

微波电子回旋共振等离子体的阻抗特性分析

基于微波电子回旋共振（ECR）等离子体中的物理和化学性质变化会引起微波传输线阻抗的变化，采用微波三探针研究了ECR等离子体的微波阻抗随装置运行参数的变化情况，并通过一个简单的放电等效电路将阻抗的变化和等离子体性质的变化联系起来。实验结果表明，通过对ECR等离子体进行阻抗特性分析，可以在不对其产生干扰的情况下了解其性质的变化。阻抗特性分析为ECR等离子体的机理研究提供了一种新的诊断途径，有利于ECR等离子体工艺的推广和应用。     

HT—6M和HT—7托卡马克的多发靶丸注入试验研究

最大发射能力为８ 发的多发 “原位” 靶丸注入装置已在中科院等离子体所建成。在 Ｈ Ｔ－ ７ ,中国第一座超导托卡马克和 Ｈ Ｔ－ ６ Ｍ 上进行了单发及多发试验。其差分单元及控制单元稳定可靠, 试验中测量了靶丸的尺寸和速度, 观察到显著而典型的物理现象, 实现了深度加料。加料效果显著,在单发靶丸注入时中心弦平均密度增长约５０ ％ ,双发注入时约１００ ％ 。实验中也观察到了明显的电子温度中空分布。文章介绍了系统的结构及操作,给出了实验现象及初步的物理分析结果。     

高频冰冻弹丸制备系统的研制及其工程调试

与俄罗斯培林实验室联合研制的60Hz高频冰冻弹丸制备系统已研制完成:能制备直径Φ1.0mm、长度L1.0mm~1.3mm可调节的圆柱形冰冻弹丸;最高注入频率60Hz;注入速度100m/s~300m/s。工程调试结果表明,弹丸制备系统能稳定可靠地运行,能较好地制备冰冻弹丸,为在HL-2A/2M装置上开展弹丸注入相关物理研究提供基础。     

Modeling of wave propagation and absorption in electron cyclotron resonance ion source plasmas

The performance of electron cyclotron resonance ion sources (ECRIS) is critically dependent on the resonant absorption of microwave power. However, currently there is little understanding of the propagation and absorption of electromagnetic waves in these ion sources. Measurement of the electromagnetic fields in a source is difficult without perturbing the plasma, and theory is hindered by the complex interaction between the waves, the plasma, the walls of the device, and the magnetic field. In this paper we present the results of quantitative 1D and qualitative 3D simulations of wave propagation and absorption in an electron cyclotron resonance ion source. The 1D simulations use the hot plasma dielectric tensor, which has not previously been applied to ECRIS modeling. The 3D simulations are the first attempt to include absorption by the plasma in calculating the structure of the electromagnetic fields in an ECRIS. These simulations demonstrate that the wave propagation and absorption is strongly dependent on the plasma. The results of the simulations are compared to experimental measurements of the mode structure, energy absorption, and frequency scaling.     

电子回旋共振CF4+O2等离子体中Si3N4刻蚀工艺研究

在一台自行研制的电子回旋共振 (ECR)刻蚀系统中用CF4、O2 气体实现了Si3 N4材料的微细图形刻蚀。获得了气体流量、气体混合比、微波功率等因素对刻蚀速率的影响。结果表明刻蚀速率在O2 含量为 0 %时最慢 ,然后随着气体混合比的增加而增大 ,当气体中O2 含量为 2 0 %时达到最大 ,然后随着气体混合比的增加而缓慢降低。保持气体混合比为 2 0 % ,刻蚀速率随气体流量增加而增大 ;同时 ,微波功率越大 ,刻蚀速率也越高。     

The role of radiative damping in shaping of the cyclotron resonance line in a two-dimensional electron system

It is shown that the broadening of a cyclotron resonance line in a two-dimensional (2D) electron system relative to the inverse scattering time of electrons is connected with the radiative damping accompanying the cyclotron motion of electrons. Using the radiative damping concept, a simple and physically informative formula describing the cyclotron resonance curve shape in a 2D electron system was obtained.     

Low-loss electron beam transport in a high-power, electrostatic free-electron maser

At the FOM Institute for Plasma Physics “Rijnhuizen”, The Netherlands, the commissioning of a high-power, electrostatic free-electron maser is in progress. The design target is the generation of 1 MW microwave power in the frequency range 130–260 GHz. The foreseen application of this kind of device is as a power source for electron cyclotron applications on magnetically confined plasmas.

The device is driven by a high-power electron beam. For long-pulse operation a low loss current is essential. A 3-A electron beam has been accelerated to energies ranging from 1.35 to 1.7 MeV and transported through the undulator at current losses below 0.02%. Further, it was shown that the beam line accepts an electron energy variation of 5% with fixed beam optics. This is essential for rapid tuning of the microwave frequency, over 10%.

Electron beam simulations have shown to be remarkably accurate both for the prediction of the lens settings and for the intercepted current. The operational settings of the beam line which give the highest current transmission are within a few percent of the simulated values.     

HT-7托卡马克氘丸注入实验研究

简要介绍了用于国家中型超导托卡马克装置HT-7弹丸注入系统;详细阐述了在HT-7装置首次用于加料实验的氘(D2)丸的成冰工艺、氘丸注入实验以及氘丸注入对等离子体产生的影响;研究了等离子体的密度、温度的分布变化。     

Production of cast aluminium-graphite particle composites using a pellet method

Copper- and nickel-coated graphite particles can be successfully introduced into aluminium-base alloy melts as pellets to produce cast aluminium-graphite particle composites. The pellets were made by pressing mixtures of nickel- or copper-coated graphite particles and aluminium powders together at pressures varying between 2 and 20 kg mm^–2. These pellets were dispersed in aluminium alloy melts by plunging and holding them in the melts using a refractory coated mild steel cone, until the pellets disintegrated and the powders were dispersed. The optimum pressure for the preparation of pellets was 2 to 5 kg mm^–2 and the optimum size and percentage of aluminium powder were 400 to 1000m and 35 wt% respectively. Under optimum conditions the recovery of the graphite particles in the castings was as high as 96%, these particles being pushed into the last freezing interdendritic regions. The tensile strength and the hardness of the graphite aluminium alloys made using the pellet method are comparable to those of similar composites made using gas injection or the vortex method. The pellet method however has the advantage of greater reproducibility and flexibility. Dispersion of graphite particles in the matrix of cast aluminium alloys using the pellet method increases their resistance to wear.Formerly with Indian Institute of Science, Bangalore, India.     

Application of semiconductors for dosimetry of fast-neutron therapy beam

Two types of ion implanted miniature p-i-n diodes were tested in a d(48.5) + Be fast-neutron beam produced in the Detroit superconducting cyclotron. The increase in forward voltage drop caused by neutron-induced damage was correlated with neutron dose measured in a water phantom. The neutron and gamma dose components were predetermined using twin detector (Tissue-equivalent ion chamber paired with miniature Geiger-Müller counter) method. The increase in the voltage drop for 1 mA injection current was monitored together with the cyclotron beam target current, thus the differential voltage drop could be defined precisely for given radiation dose. The average neutron sensitivities of tested diodes were 1.284 +/- 0.014 and 0.528 +/- 0.058 mV per cGy. The miniature detectors can be utilised in characterisation of small radiation fields and in the regions of high dose gradient as well as for in vivo dosimetry of the patients undergoing fast-neutron therapy.     

Power-law-type electron injection through lithium fluoride nanolayers in phosphorescence organic light-emitting devices

This work reports a power-law-type electron injection model that accounts for the thickness effect of lithium fluoride (LiF) nanolayers used as an electron injection layer in phosphorescence organic light-emitting devices (PHOLEDs). A series of PHOLEDs were fabricated with various LiF thicknesses in order to investigate the influence of LiF nanolayer thickness on the device current. The PHOLEDs exhibited pronouncedly changed electron currents by only 0.2?nm thickness variation. The device current as a function of LiF thickness excellently followed the power-law model proposed in this study, from which a physical constant indicating the intrinsic nature of electron injection materials has been extracted.