气压对氩等离子体特性的影响

研制了一种新的大面积微波等离子体源。由环形波导腔环绕直径３０ｃｍ、高５０ｃｍ耐热玻璃圆筒真空室构成。环形波导内侧开有多个狭缝用来激励产生等离子体。利用该源研究了气压对等离子体参数、击穿功率和熄灭功率的影响。     

环形波导等离子体源阻抗特性的研究

采用微波三探针研究了环形波导等离子体源阻抗特性随运行参数的变化。分析了微波等离子体源的阻抗特性。该方法有助于微波等离子体特性的研究和实现快速阻抗调配。     

宽气压范围内裂缝天线等离子体特性研究

给出了气压为10～28000Pa时,环形倾斜裂缝天线等离子体源的放电特性.实验表明,该源在气压为10～2600Pa范围内是大体积表面波放电,并且在气压为10和230Pa时清楚地观察到裂缝天线附近石英管内的等离子体有较明显的8个瓣和12个瓣(表面波模式可确定为m=4和m=6);当气压升高到4000～6000Pa时,在石英管的底端和不锈钢真空室交界处激励起直径约为12cm的高密度等离子体椭球(1011cm-3量级);在气压为11000～14000Pa时,发现等离子体有明显的涡动现象;而当气压上升到20000Pa以上,等离子体有丝状结构出现.     

宽气压范围内裂缝天线等离子体特性研究

给出了气为10－28000Pa,环形倾斜裂缝天线等离子体源的放电特性,实验表明,该源在气压为10－2600Pa范围内是大体积表面波放电,并且在气压为10和230Pa时清楚地观察到裂缝天线附近石英管内的等离子体有较明显的8个瓣和12个瓣（表面波模式可确定为m=4,和m=6）,当气压升高到4000－6000Pa时,在石英管的底端和不锈钢真空室交界处激励起直径约为12cm的高密度等离子体椭球（10^11cm^-3量级）,在气压为11000－14000Pa时,发现等离子体有明显的涡动现象,而当气压上升到20000Pa以上,等离子体有丝状结构出现。     

微波等离子体中OH自由基的光腔衰荡光谱诊断

搭建了一套以可调谐半导体激光器为光源的连续波光腔衰荡光谱装置,将其与微波等离子体装置结合,对等离子体中的OH自由基进行了原位定量测量,同时考察了OH自由基数密度随气压和微波功率的变化情况.实验结果表明:以氮气为工作气体,在(0.66～3.99)×103Pa范围内,随着气压的升高,OH自由基数密度先增加后降低,在1.995×103Pa时达到最大值;随着微波功率的升高OH自由基数密度逐渐增加.     

环形波导微波场分布的计算

提出了环形波导场分布的计算模型 ,计算了环形波导内的微波场分布。结果表明即使在环形腔直径大于微波波长时 ,微波能量也能传到真空室中心附近 ,这为实现大面积均匀等离子体提供了理论依据     

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。     

工频脉冲激励条件下线形微波H2等离子体的Langmuir探针诊断

在金刚石膜的化学气相沉积过程中，使用脉冲电源激励的微波等离子体可以提高金刚石膜的沉积速率或金刚石膜的质量。本文使用Langmuir探针研究了在工频脉冲电源激励条件下形成的线形微波H2等离子体的状态和开关特性。实验测量了在使用一支磁控管单独激励和两支磁控管共同激励情况下的H2等离子体的状态参量，包括等离子体的空间电位‰、探针悬浮电位Vf、电子温度Te和电子密度ne随时间的变化，特别是讨论了H2等离子体参量在激励电源开启与关断瞬间的过渡特征。     

Waveguide-surfatron型表面波等离子体源的特性研究

报道了所研制的Waveguide-surfatron型表面波等离子体源的特性,理论计算表明,激发表面波模式为m≥l模,在放电室中电磁场均匀性与等离子体的密度有关。实验结果指出,采用Ar气放电,在气压为10～1000Pa,微波功率800～1000W的范围内可形成大面(体)积(直径为160mm)等离子体,其电子温度为1～4eV,等离子体密度为10     

双侧波导同轴线耦合式线形微波等离子体源的研究

本文介绍了一种具有双侧波导同轴线耦合结构的新型微波等离子体源。通过电磁场模拟计算和等离子体发射光谱测量对同轴线耦合反应腔内部结构进行了优化,研究了线形等离子体源腔体结构对等离子体均匀性和长度的影响,并且在杆状样品表面进行了金刚石薄膜的沉积实验。实验结果表明:双侧波导同轴线耦合式新型线形等离子体源可以在引导天线表面产生圆柱状的线形等离子体,其等离子体的均匀性和长度受腔体内部结构的影响,在引导天线外径为4 mm,单侧模式匹配棒伸入量为10 mm的腔体结构下,等离子体的均匀性大于90%。通过对杆状样品表面不同位置处金刚石膜质量和等离子体沉积环境的测量,进一步验证了等离子体的均匀性。此外,线形等离子体的长度受引导天线长度和工作气压影响,这主要与反应腔内电磁场分布以及微波传输衰减有关。     

A Simulator for Producing of High Flux Atomic Oxygen Beam by Using ECR Plasma Source

In order to study the atomic oxygen corrosion of spacecraft materials in low earth orbit environment, an atomic oxygen simulator was established. In the simulator, a 2.45 GHz microwave source with maximum power of 600 W was launched into the circular cavity to generate ECR (electron cyclotron resonance) plasma. The oxygen ion beam moved onto a negatively biased Mo plate under the condition of symmetry magnetic mirror field confine, then was neutralized and reflected to form oxygen atom beam. The properties of plasma density, electron temperature, plasma space potential and ion incident energy were characterized. The atomic oxygen beam flux was calibrated by measuring the mass loss rate of Kapton during the atomic oxygen exposure. The test results show that the atomic oxygen beam with flux of 1016-1017 atoms-cm-2·s-1 and energy of 5-30 eV and a cross section of φ80 mm could be obtained under the operating pressure of 10-1-10-3 Pa. Such a high flux source can provide accelerated simulation tests of mater     

Optical emission patterns and microwave field distributions in a cylindrical microwave plasma source

A cylindrical high density (10¹² cm⁻³) large volume (32 cm in diameter and 50 cm in length) homogeneous argon plasma has been produced by a microwave with a frequency of 2.45 GHz and a power of 900 W without a magnetic field. The plasma source is based on a ring shaped rectangular waveguide with eight equally spaced slots in its inside wall. Several optical emission patterns are observed on different conditions and the microwave field is measured by a movable antenna, which showed a clear relationship between the optical emission patterns and the electron field distributions. A mode transition, from a TE_8j mode to a TE_16j mode, occurs when the gas pressure increases from 660 to 1000 Pa. And there is an optical emission pattern when the microwave power decreases from 900 to 300 W. All these phenomena are described in detail and analyzed according to the interactional theory of electrons in plasma with microwave.     

用于电离层环境模拟器的ECR等离子体源

为了经济地考验空间电离层等离子体对处于其中的飞行器表面的作用,需要在地面建立等离子体环境模拟器。本文就是为空间电离层环境模拟器研制的扩散型极低气压、低电子温度和极低密度的紧凑型电子回旋共振等离子体源的研制。结果显示在等离子体源下游50cm处,在10-2～10-3Pa范围内获得了电子温度低于5eV,密度在104～106cm-3范围内的较为均匀的等离子体束流,基本满足了空间环境模拟实验的需要。     

Production of high density and large volume plasma by using a polyphase AC voltage source

Production of high density and large volume plasma for a plasma source ion implantation has been studied. Plasma is produced by a polyphase AC voltage source with maximum voltage and power of 2 kV and 12 kVA, respectively. Produced N₂ plasma had a small ripple frequency of 720 Hz and a ripple ratio of 20% though frequency of the AC voltage source was 60 Hz. At output voltage of 600 V and N₂ gas pressure of 5 Pa, plasma density in 6-phase operation and 12-phase operation were 8×10⁸ cm⁻³ and 4×10⁹ cm⁻³, respectively. The plasma density in 12-phase operation was about five times larger than that in 6-phase operation. Electron temperature of 0.9 eV was obtained in both operations. The uniform plasma was produced in the inner region of the ring basket electrode which had a radius of 20 cm and length 80 cm at 12-phase operation. The plasma density was increased in proportion to the N₂ gas pressure and output voltage of the AC voltage source. When line-cusp magnets were attached to the process chamber wall, the plasma density increased about 2.5 times.     

聚焦离子束系统中微波离子枪的束光学特性研究

通过实验和数值模拟研究了聚焦离子束系统中微波离子枪的离子束光学特性，该离子枪由微波等离子体源和Orloff-Swason引出透镜组成。该透镜除了广泛用于场致发射离子枪外，在等离子体源情况下，也能获得很好的离子束光学性能。     

同轴阻抗变换器低气压放电研究

低气压放电效应是由微波电离击穿引起的气体放电现象,是限制大功率微波部件功率容量的关键可靠性问题之一。以同轴结构微波部件为研究对象,对S波段同轴阻抗变换器进行了低气压放电实验研究。实验结果表明:同轴阻抗变换器的低气压放电行为近似符合帕邢曲线。基于考虑扩散、电离、吸附的气体放电理论,建立了同轴传输线结构微波电离击穿功率阈值的计算模型。模型计算结果表明:气体温度升高会导致微波电离击穿阈值曲线向低气压区域平移;局部场增强效应会降低同轴阻抗变换器的低气压放电功率阈值。     

Determination of metastable atom concentration by use of electrostatic probe technique

A method for determination of the metastable atom concentration in high pressure (>100 Torr) high density (> 10¹²cm²³); helium plasma from current–voltage characteristics of a single electrostatic probe is described. It is shown, that the flux of metastable atoms to the probe is controlled by ion sheath thickness and consequently by probe bias. The method for calculation of metastables concentration from the negative part of the current–voltage probe characteristics is proposed. The metastables concentrations measured in pulsed microwave discharge are in agreement with values calculated from the metastable balance equation.