Development of a helicon-wave excited plasma facility with high magnetic field for plasma-wall interactions studies

The high magnetic field helicon experiment system is a helicon wave plasma(HWP)source device in a high axial magnetic field(B_0)developed for plasma–wall interactions studies for fusion reactors.This HWP was realized at low pressure(5?×?10~(-3)?-?10 Pa)and a RF(radio frequency,13.56 MHz)power(maximum power of 2 k W)using an internal right helical antenna(5 cm in diameter by 18 cm long)with a maximum B_0of 6300 G.Ar HWP with electron density~10~(18)–10~(20)m~(-3)and electron temperature~4–7 e V was produced at high B_0 of 5100 G,with an RF power of 1500 W.Maximum Ar~+ion flux of 7.8?×?10~(23)m~(-2)s~(-1)with a bright blue core plasma was obtained at a high B_0 of 2700 G and an RF power of 1500 W without bias.Plasma energy and mass spectrometer studies indicate that Ar~+ion-beams of 40.1 eV are formed,which are supersonic(~3.1c_s).The effect of Ar HWP discharge cleaning on the wall conditioning are investigated by using the mass spectrometry.And the consequent plasma parameters will result in favorable wall conditioning with a removal rate of 1.1?×?10~(24)N_2/m~2 h.     

Cr掺杂SiC薄膜的制备与光玫发光特性

利用高纯SiC烧结靶上粘贴金属Cr片的复合靶用双离子束溅射沉积方法,在Si和KBr单晶衬底上制备了掺杂SiC薄膜.用傅里叶变换红外光谱分析法(FTIR)和喇曼光谱仪对制得的薄膜样品进行了表征,用荧光分光光度计对样品的光致发光(PL)特性进行了研究.通过FTIR分析得到对应于Si-C键的峰位没有发生明显改变而峰强随着Cr掺杂量的增加而降低,喇曼光谱分析发现Cr掺杂导致Si和C团簇的形成,说明Cr的掺杂阻碍了Si-C键的结合.将不同Cr掺杂浓度的SiC薄膜经1000℃退火处理,发现位于413、451和469nm的三个发光峰的位置基本不变,但强度有明显改变.     

生长温度对热蒸发法制备ZnO纳米线的结构与发光性能影响

采用无金属催化剂的简单热蒸发法,在Si(100)衬底上不同生长温度下成功地制备了高密度和大长径比的单晶ZnO纳米线。分别利用X射线衍射仪(XRD)、扫描电子显微镜(SEM-EDS)、透射电子显微镜(TEM)及荧光光谱仪表征样品的结构和发光性质。XRD和TEM研究表明,所制备的样品为沿C轴择优取向生长的单晶ZnO纳米线,具有六方纤锌矿结构。SEM和TEM研究表明,生长温度对ZnO纳米线的形貌及长径比的影响较大。当生长温度为700℃时,制备得到长径比为300(长度约为15μm,直径约为50nm)的ZnO纳米线。低于600℃时,形成花状ZnO纳米锥或 纳 米 棒。高 于700℃时,形 成 小 长 径 比 的ZnO纳米棒。此外,室温光致发光(PL)谱上出现一个强而尖锐的紫外发射峰以及一个弱而宽泛的蓝光发射峰。采用的热蒸发法制备ZnO纳米线基于气-固(VS)生长机理且该生长方法可用于大规模、低成本制备高纯度的单晶ZnO纳米材料。     

The properties of N-doped diamond-like carbon films prepared by helicon wave plasma chemical vapor deposition

In this paper, N-doped diamond-like carbon(DLC) films were deposited on silicon substrates by using helicon wave plasma chemical vapor deposition(HWP-CVD) with the Ar/CH_4/N_2 mixed gas. The surface morphology, structural and mechanical properties of the N-doped DLC films were investigated in detail by scanning electron microscopy(SEM), x-ray photoelectron spectroscopy(XPS), Raman spectra, and atomic force microscopy(AFM). It can be observed from SEM images that surface morphology of the films become compact and uniform due to the incorporation of N. The maximum of the deposition rate of the films is 143 nm min~(-1), which is related to the high plasma density. The results of XPS show that the N incorporates in the films and the C-C sp~3 bond content increases firstly up to the maximum(20%) at 10 sccm of N_2 flow rate, and then decreases with further increase in the N_2 flow rate. The maximum Young's modulus of the films is obtained by the doping of N and reaches 80 GPa at 10 sccm of N_2 flow rate, which is measured by AFM in the scanning probe microscope mode. Meanwhile, friction characteristic of the N-doped DLC films reaches a minimum value of 0.010.     

高密度螺旋波等离子体源的应用进展

首先介绍了螺旋波的定义、螺旋波等离子体源产生等离子体所需条件的工作范围以及螺旋波等离子体源主要的一些应用.按照所加磁场范围的不同(分为在磁感应强度为100～1 600 Gs和在强磁场中两部分),分别进一步讨论了国内外各研究小组研制的等离子体源的运行参数及技术特点.随后介绍了螺旋波等离子体源在刻蚀、薄膜沉积和火箭推进三个...     

生长温度对热蒸发法制备ZnO纳米线的结构与发光性能影响

采用无金属催化剂的简单热蒸发法,在Si(100)衬底上不同生长温度下成功地制备了高密度和大长径比的单晶ZnO纳米线。分别利用X射线衍射仪(XRD)、扫描电子显微镜(SEM-EDS)、透射电子显微镜(TEM)及荧光光谱仪表征样品的结构和发光性质。XRD和TEM研究表明,所制备的样品为沿c轴择优取向生长的单晶ZnO纳米线,具有六方纤锌矿结构。SEM和TEM研究表明,生长温度对ZnO纳米线的形貌及长径比的影响较大。当生长温度为700℃时,制备得到长径比为300(长度约为15μm,直径约为50nm)的ZnO纳米线;低于600℃时,形成花状ZnO纳米锥或纳米棒;高于700℃时,形成小长径比的ZnO纳米棒。此外,室温光致发光(PL)谱上出现一个强而尖锐的紫外发射峰以及一个弱而宽泛的蓝光发射峰。采用的热蒸发法制备ZnO纳米线基于气-固(VS)生长机理且该生长方法可用于大规模、低成本制备高纯度的单晶ZnO纳米材料。     

风险管理在瓶装气体安全生产中的应用

由于气瓶充装过程具有易燃、易爆的危险特性,因此在瓶装气体生产企业需要一种行之有效的系统安全管理方法,来对安全风险实施预测和控制,避免事故发生。武钢氧气公司将危险辩识、风险评价和风险控制的风险管理方法应用于瓶装气体的生产管理中,取得了较好的效果。简析武钢氧气公司瓶装气体生产的工艺特点和基本危害,以及安全生产方面存在的主要问题;介绍瓶装气体生产过程中的风险分析和评价,以及相应的风险防范策略。     

CCP/ICP混合放电C4F8/Ar等离子体高、低频功率对AZO薄膜绒面效果的影响

室温下,采用射频磁控溅射方法在石英基片上制备掺铝氧化锌(AZO)透明导电薄膜。利用CCP/ICP混合放电C4F8/Ar等离子体对制得的AZO薄膜进行绒面处理。利用原子力显微镜(AFM)对薄膜表面形貌进行表征,利用光纤光谱仪分析放电产生的碳氟基团含量的变化。实验结果发现低频功率的增大能够有效增加等离子体中F原子的含量,进而提高薄膜的刻蚀效果,获得较好的绒面结构;但是高频功率变化对薄膜刻蚀效果影响较小。