等离子体与石墨及其涂层相互作用的研究

应用ＬＡＳ－２０００辐照设备、射频离子源设备及ＨＬ－１Ｍ装置对等离子体与石墨及其涂层的相互作用进行了系统研究,为进一步优化ＨＬ－１Ｍ装置原位处理工艺、杂质控制以及ＨＬ－２Ａ装置第一壁的选材和第一壁处理、杂质控制等提供依据。     

HL—1M装置边缘等离子体测量

本文研究了ＨＬ－１Ｍ装置运行初期第一壁材料对等离子体删削层杂质流通量及分布的影响，并与ＨＬ－１装置的结果进行比较。利用热通量探针测量，给出了ＨＬ－１和ＨＬ－１Ｍ装置删削层的热通量分布。在不同运行状态下，利用马赫探针组，测量了ＨＬ－１Ｍ装置边缘等离子体流的变化特性。     

GaAs衬底上生长的GaInP_2外延单晶薄膜的杂质污染研究

各种外延技术已被用来在ＧａＡｓ衬底上生长ＧａｘＩｎ１－ｘＰ外延单晶薄膜（ＧａＩｎＰ２／ＧａＡｓ）．很多文献认为,在ＧａＩｎＰ２／ＧａＡｓ生长过程中会被Ｃ杂质污染．我们用高灵敏的ＣＡＭＥＣＡＩＭＳ４Ｆ型二次离子质谱仪直接测量的结果表明,污染ＧａＩｎＰ２／ＧａＡｓ的微量杂质是Ｓｉ,而不是Ｃ．由ＧａＩｎＰ２／ＧａＡｓ在１．１７ｅＶ附近的光致发光峰的峰值随激发强度的变化形状表明了它应属于施主－受主对复合发光．进一步分析表明,施主为处在Ｇａ格位上的Ｓｉ杂质（ＳｉＧａ）,受主为Ｇａ空位（ＶＧａ）．     

HL－1M装置杂质VUV辐射及Te观测

本文介绍了ＨＬ－１Ｍ装置等离子体杂质真空紫外辐射观测的初步结果。用类Ｌｉ离子谱线强度比法估计出Ｔｅ≈４００ｅＶ。镀膜后的ＣＥＭ探测器的灵敏度提高。杂质对装置放电有重要影响     

HL—1M装置杂质VUV辐射及Te观测

本文介绍了ＨＬ－１Ｍ装置等离子体杂质真空紫外辐射观测的初步结果。用类Ｌｉ离子谱线强度比法估计出Ｔｅ≈４００ｅＶ。镀膜后遥ＣＥＭ探测器的灵敏度提高。杂质对装置放电有重要影响。     

HL—1装置的金属杂质沉积实验

采用立体探针与二次离子质谱计（ＳＩＭＳ）分析相结合，对ＨＬ－１装置刮削层空间的杂质沉积特性和分布规律进行了实验研究。测量了在石墨活动孔栏条件下，立体针表面杂质沉积特性和分布规律进行了实验研究。测量了在石墨活动孔栏条件下，立体探针表面杂质沉积的径向分布，纵向分布，极向分布和Ｈ＾＋剖面分布。并讨论了实验结果。     

低混杂波电流驱动下注入杂质的输运

在欧姆放电和低混杂波电流驱动条件下,应用激光吹气技术注入金属杂质,用真空紫外谱仪测量了杂质线的辐射,给出了ＨＬ－１Ｍ 装置欧姆等离子体和低混杂波电流驱动等离子体杂质输运的研究结果。用杂质输运程序ＬＢＯ进行数值模拟,得出了等离子体中杂质的扩散系数Ｄ（ｒ） 和对流速度ｖ（ｒ）。在低混杂波电流驱动条件下,等离子体杂质的输运系数相对欧姆放电等离子体杂质的输运系数减小了５０％ 左右。结果表明,在ＨＬ－１Ｍ 装置上低混杂波电流驱动等离子体相对通常欧姆等离子体杂质的约束性能明显得到了改善     

高偏压金属─绝缘体─金属结的光发射

我们制作了一种可在６—１１Ｖ偏压范围内均匀发射可见光的新型金属—绝缘体—金属结型发光器件，其内层结构是Ａｌ－Ａｌ２Ｏ３－ＭｇＦ２－Ａｎ（Ｃｕ），其承受偏压、单位面积发光功率及相应的外量子效应高过迄今已知的Ｍ－Ｏ－Ｍ遂道结型发光器件．本文首次报导并论证了这一由Ｓｃｈｏｔｔｋｙ热电子所激发的光发射及其物理图象：Ｓｃｈｏｔｔｋｙ热电子在ＡＯ（Ｃｕ）－真空界面激发表面等离极化激元（ＳＰＰ）；Ａｕ（Ｃｕ）－真空界面的ＳＰＰ通过表面粗糙度与外光子耦合．这一图象与该器件的电流—电压（Ｉ—Ｖ）、电流—温度（Ｉ－Ｔ）关系及其发射光谱的主要特征一致．     

MPEG-2先进音频编码(AAC)的研究和软件仿真

ＭＰＥＧ－２ＡＡＣ是ＩＳＯ／ＩＥＣ ＭＰＥＧ组织继 ＭＰＥＧ－１、ＭＰＥＧ－２音频编解码标准后,制定 的最新国际标准（ＩＳＯ／ＩＥＣ １３８１８－７）,在６４ｋｂｐｓ／每声道低码率时能提供全透明音质。本文对其编 解码算法进行了简要介绍。论文作者对ＭＰＥＧ－２ＡＡＣ进行了软件仿真,文中介绍了仿真结果,仿 真时对ＡＡＣ标准所附编码范例中的一些不妥之处,作了改进,文中列举了６方面的修正。     

MPEG-2先进音频编码(AAC)的研究和软件仿真

ＭＰＥＧ－２３ＡＡＣ是ＩＳＯ／ＩＥＣＭＰＥＧ组织继ＭＰＥＧ－１,ＭＰＥＧ－２音频编解码标准后,制定的最新国际标准（ＩＳＯ／ＩＥＣ１３８１８－７）在６４ｋｂｐｓ／每声道低码率时能提供全透明音质,本文对其编解码算法进行了简要介绍,论文作者对ＭＰＥＧ－２ＡＡＣ进行了软件仿真,文中介绍了仿真结果,仿真时对ＡＡＣ标准所附编码范 中的一些不妥之处,作了改进,文中列举了６方面的修正。     

射频溅射沉积硅薄膜实验

本文描述采用射频溅射法在GH39不锈钢基体上沉积硅薄膜的实验。对直接溅射沉积硅薄膜的工艺进行了实验研究,并对硅膜进行了SIMS分析。用称重法测出无定形硅膜的最大厚度可达400—500nm,为HL-1装置等离子体边界层物理实验制作了所需的无定形硅膜收集探针。     

Quantitative fundamental SIMS studies using O implant standards

The use of dilute ‘minor-isotope’ ¹⁸O implant reference standards for quantification of surface oxygen levels during steady-state SIMS depth profiling is demonstrated. Some results of two types of quantitative fundamental SIMS studies with oxygen (¹⁶O) primary ion bombardment and/or oxygen flooding (O₂ gas with natural isotopic abundance) are presented: (1) Determination of elemental useful ion yields, UY(X^±), and sample sputter yields, Y, as a function of the oxygen fraction c_O measured in the total flux emitted from the sputtered surface. Examples include new results for positive secondary ion emission of several elements (X = B, C, O, Al, Si, Cu, Ga, Ge, Cs) from variably oxidized SiC or Ge surfaces. (2) The dependence of exponential decay lengths λ(Au^±) in sputter depth profiles of gold overlayers on silicon on the amount of oxygen present at the sputtered silicon surface. The latter study elucidates the (element-specific) effects of oxygen-induced surface segregation artifacts for sputter depth profiling through metal overlayers into silicon substrates.     

HL-1装置中的等离子体与器壁相互作用

本文对HL-1装置欧姆加热放电时,等离子体—器壁相互作用进行了实验研究。质谱分析定性地指出,主要气相杂质H_2O来自零级表面化学反应,CH_4来自多步骤合成表面化学反应,CO(CO_2)则来自碰撞表面化学反应。收集探针的表面分析显示出,Mo,Cr和Ni等为主要的重杂质;蒙特卡罗模拟分析给出了氢粒子注入硅探针的特征深度和其动力温度的拟合直线关系式。     

HL—1装置碳化和采用抽气孔栏时的可见辐射观测

本文描述了HL-1装置器壁碳化和采用抽气孔栏时,氢及杂质通量的变化情况;利用多道可见辐射的时空分布测量,得到了MARFE放电,在产生MARFE时,辐射热也相应增强。     

HL-1托卡马克放电辐照的因科镍和铝的表面效应研究

核聚变能是最有希望的一种新能源,我国自行设计与建造的核聚变装置——HL-1已于1985年投入运行。研究核聚变装置中等离子体与器壁、孔栏材料相互作用日益受到广泛重视,因为这种反应造成等离子体的污染及聚变装置材料灼损坏。同时,这一研究还将提供等离子体边界层的性能参数,为下一代装置的器壁材料选择和结构设计提供参考。本文研究了镍基合金和铝探针在HL-1装置的等离子体括削层内,经等离子体辐照后的表面形貌及表面组分的变化。     

HL-1装置放电清洗系统和实验

本文描述了HL-1装置的泰勒放电清洗系统和其清除氧、碳等轻杂质的能力。研究了水分压强的某些特性及其同充氢气压、等离子体电流(电子温度)、电子密度的关系。从而找到了HL-1装置的泰勒放电清洗最佳运行参数。     

Uptake of hydrogen from some carbon fibres examined by Secondary Ion Mass Spectrometry

The use of carbonaceous materials for hydrogen storage is not as simple as it may seem. Hydrogen atoms have different bonding energies and are incorporated into different types of these materials. Therefore, it is particularly important to distinguish between the surfacial atoms and those that are embedded in the bulk of the sample.SIMS spectrograph with periodical interruptions of the ion beam enables us to appreciate that at room temperature and in high vacuum, some outgassing of the surfacial hydrogen takes place.     

Surface analysis of thermally annealed porous silicon

Quasi-monocrystalline porous silicon (QMPS) has high potential for photovoltaic application for its enhanced optical absorption compared to bulk silicon in the visible range of solar spectrum. In this study, QMPS was formed from low porosity (∼20-30%) porous silicon (PS) produced by electrochemical anodization, and thermal annealing in the temperature range 1050-1100 °C under pure hydrogen ambient for a duration of 30 min. We analyzed the material surface by grazing incidence X-ray diffraction (GIXRD), field emission scanning electron microscopy (FESEM), atomic force microscopy (AFM) and dynamic secondary ion mass spectroscopy (SIMS) study. The crystallinity was confirmed by GIXRD while FESEM studies revealed that the surface layer is pore free with voids embedded inside the body. AFM studies indicated relatively smooth and uniform surface and the dynamic SIMS study showed the depth profiles of impurities present in the material.     

An isotope effect in electrolytic hydrogen absorption of some transition metals studied by ERDA and SIMS techniques

The depth profiles of protium and deuterium which were charged electrolytically, were measured by elastic recoil detection analysis (ERDA) and secondary ion mass spectrometry (SIMS) techniques in order to study the isotope effect in hydrogen absorption of Ti, Zr, Nb, Ni and Pd. The absolute loading ratios of H(D)/metal were calculated from the ERDA spectra and the depth profiles of SIMS were compared with the results of the ERDA. The isotope absorption ratios are estimated to be (D/H)_Ti=0.43, (D/H)_Zr=0.53, (D/H)_Nb=0.17 and (D/H)_Pd=0.10. The content in Ni is below the detection limit. The mass balance equations based on the transport–absorption model, were applied to analysis of the experimental results. This model reveals that the isotope absorption ratios for the Nb and Pd cases are governed mainly by the flux of hydrogen ions flowing to the surface of the metal electrode. However, the competition between the absorption–conversion process and the recombination process mainly determine the isotope ratio for the Ti and Zr cases.