用于离子束辅助镀膜的两种模式端部霍尔离子源的比较

介绍了一种用于离子束辅助沉积光学薄膜的端部霍尔离子源的工作原理,并论述了端部霍尔离子源的离子能量、离子分布特性的测试方法;详细论述了电磁场和永久磁场两种模式下,端部霍尔离子源的工作稳定性、离子能量大小以及离子束分布特性的比较.     

端部中空离子源的磁路研究

研究了端部中空离子源的磁路设计.在简要叙述端部中空离子源的基本原理及其对磁场要求的基础上,考虑了在设计离子源磁路时的关键问题和解决方法,并给出了实验结果和分析结论.     

端部霍尔等离子体源沉积类金刚石膜的研究

本文通过对端部霍尔离子源特性的研究 ,采用自行研制的用于离子束辅助沉积的端部霍尔离子源成功镀制了类金刚石膜 ,并对采用该离子源制备类金刚石膜的工艺进行了研究和分析。实验结果表明 ,采用端部霍尔离子源镀制类金刚石膜不仅操作简单、可实现大面积沉积 ,而且类金刚石膜的沉积速率较大 ,最大可达 0 .8nm s,其折射率依不同工艺在 1.8～ 2 .2之间可调。并对不同工艺条件下制备的类金刚石膜的硬度进行了测试和分析。     

端部霍尔离子源工作特性及等离子体特性研究

研制了一种用于离子束辅助沉积光学薄膜的端部霍尔等离子体离子源，论述了该源的工作原理以及伏安特性。着重研究了用五栅网探针测试该源所发射的离子能量的原理和方法，并对测量结果进行了分析、比较。对该离子源的离子束流密度和均匀性进行了测试和分析。     

端部霍尔离子源工作特性及等离子体特性研究

研制了一种用于离子束辅助沉积光学薄膜的端部霍尔等离子体离子源 ,论述了该源的工作原理以及伏安特性。着重研究了用五栅网探针测试该源所发射的离子能量的原理和方法 ,并对测量结果进行了分析、比较。对该离子源的离子束流密度和均匀性进行了测试和分析     

阳极磁屏蔽霍尔离子源磁场的数值模拟

为了提高离子束电流和离子束能量,进一步增加霍尔离子源的效率,对霍尔离子源阳极进行磁屏蔽,达到优化磁场位形,增强磁场对放电等离子体的约束。由磁场的数值模拟结果可知:阳极磁屏蔽后,有明显凸向阳极表面的弯曲磁场线,并且提高了磁镜磁场的磁镜比;大的正梯度磁场的存在,增强了磁场的径向分量,相对减弱了放电等离子体的震荡;不仅保留原有鞍形场的作用,而且还充分发挥了另外两个鞍形场的优势。最后通过实验结果和数值模拟结果的比较,验证了此数值模拟结果的正确性。     

考夫曼离子源多极磁场结构设计与数值模拟

论述了考夫曼离子源中两种磁场结构的特点.在采用多极磁场的离子源中,由于放电室内低磁场区的存在,可获得均匀性好的离子束流.采用环形永久磁体改进设计了考夫曼离子源的多极磁场,简化了磁路结构.运用Ansoft软件对多极磁场进行了数值模拟,结果分析表明设计是可行的,为该类型离子源的磁路优化设计提供了理论依据.     

冷阴极潘宁离子源的磁路研究

研究了冷阴极潘宁离子源的磁路设计，在简要叙述冷阴潘宁离子源的基本原理及其对磁场要求的基础上，考虑了在设计冷阴极潘宁离子源磁路时的关键问题和解决方法，并给出了实验结果和分析结论。     

霍尔离子源制备类金刚石薄膜研究

采用霍尔离子源沉积类金刚石薄膜是近年来新出现的一种方法，本文研究了自行研制的霍尔离子源的性能以及采用此离子源制备类金刚石薄膜及工艺参数的影响。结果表明，霍尔离子源在较低的电压即可起辉，可提供稳定的能量较低的离子束流。采用霍尔离子源沉积类金刚石薄膜的沉积速率约为O．5nm/s。随着霍尔离子源灯丝电流的升高，离子源放电电压下降，制备的类金刚石薄膜的硬度下降。放电电流的变化对类金刚石薄膜的硬度影响不大。     

三维中频磁场测量传感器的设计

针对肿瘤热疗发生装置产生的中频强磁场的测量设计三维传感器,可测量磁场空间点三坐标磁场分量,合成磁场矢量。设计制作基于霍尔器件的三维传感器,重点分析传感器的误差,对其进行标定,最后对不均匀的实验磁场进行测试,实验符合预期结果。     

Study of HfO2 films prepared by ion-assisted deposition using a gridless end-hall ion source

HfO₂ thin films were deposited using e-beam gun evaporation with ion assisted deposition (IAD) of low energy oxygen ions (40–100 eV) from an end-Hall ion source. A comparison was made using Hf and HfO₂ starting materials. The index of refraction was measured as a function of the ion source voltage and compared to results without IAD. Application to high power laser mirrors was verified by measurements of laser damage thresholds at 1.06 μm.     

Electron ionization in superimposed magnetic and radio frequency quadrupolar electric fields

An improved design of a novel electron ionization source for orthogonal acceleration time-of-flight mass spectrometry is described, based on the superimposition of an axial magnetic field with cylindrical symmetry around a radio frequency-only quadrupole. A tubular permanent magnet was designed to generate the required strong magnetic field and field profile. An axial electric field along the ion guide for efficient ion extraction was introduced using segmented quadrupole rods. Details of the source design and the effects of various operating parameters are described. The source produces high-quality mass spectra with regard to fragmentation, relative abundances, and isotopic ratios. Preliminary results have shown excellent sensitivity, with limits of detection in the subfemtogram range (octafluoronaphthalene, full spectrum acquisition) in gas chromatography/mass spectrometry operation.     

Superimposition of a magnetic field around an ion guide for electron ionization time-of-flight mass spectrometry

A new electron ionization source was developed for orthogonal acceleration time-of-flight mass spectrometry (TOFMS) based on the superimposition of a magnetic field around a radio frequency-only (rf-only) ion guide. The cylindrically symmetric magnetic field compresses the electron beam from the electron source into a long narrow volume along the ion guide axis. The magnetic field also helps to maintain a narrow energy distribution of electrons that penetrate the full length of the ion guide despite the influence of the radial rf field. Ionization occurs inside the ion guide with improved efficiency resulting from efficient use of electrons, prolonged interaction time, and nontraditionally large ionization volume. At the same time, the rf field effectively focuses ions radially and confines them to the axis of the ion guide by collisional focusing, leading to high ion transmission efficiency. Furthermore, the source can also be operated in a trap-and-pulse mode to improve the ion sampling duty cycle of orthogonal acceleration TOFMS. To validate the design concept of this new ion source, a simple prototype using a single set of cylindrical rods was constructed and retrofitted to an orthogonal acceleration TOFMS. A significant increase in ion signal intensity was observed by operating the source in a pulsed ion extraction mode. Low detection limits (for example, 12 fg for toluene) were determined at 12.5 spectra s(-1) in the full spectrum mode.     

阴极弧离子源磁过滤器的磁场设计与数值模拟

对于阴极弧离子源,磁过滤器的磁场设计是提高其性能的关键技术之一。针对现有磁过滤器对大颗粒过滤不足之处,本文利用永磁体优化磁过滤器的磁场位形,并且增大磁过滤器出口面积等方法,对弯管磁过滤器进行结构和磁场优化设计。由模拟结果可知:此过滤器具有弯管过滤、Bilek偏压、较大的出口面积、出口平面磁场强度大小均匀分布等优点。     

Simulations of negative ion extraction from a multi-aperture ion source in the presence of the magnetic filter

The particle-in-cell method based numerical model of negative ion beam extraction from a large volume multi-aperture ion source is briefly described. The model takes into account the influence of the transversal magnetic field and diffusion of electrons across the field. The current-voltage curves for H^- ions and electrons are presented. The results are compared for the three cases: without filter field; with the field but without diffusion; and with the field and electron diffusion. The presence of the magnetic filter field increases H^? yields significantly (by 200%). A random-walk electron diffusion model enables electrons to travel through the magnetic field, which reduces a nonphysical effect of excessive electron aggregation in the filter region. The changes of filter width do not alter H^? current more than 10%.     

灭弧室用磁控真空计的研究

介绍了同轴场式脉冲磁控真空计的测量原理以及设计中的有关问题。给出了某些真空灭孤室的压强－离子电流曲线。测量结果表明，该磁控计的压强－离子电流曲线为幂指数函数，磁控放电的离子电流与磁场强度无关，但磁场强度必须足以产生稳定的磁控放电。压强－离子电流曲线与灭弧室电极几何构造和触头的状况有关。     

Emittance and brightness measurements in a proton electron cyclotron resonance ion source

A new method has been developed for measuring the emittance and brightness of a proton beam extracted from an electron cyclotron resonance (ECR) ion source located inside a solenoidal magnetic field, in which the envelope of the extracted beam undergoes amplitude modulation with axial distance. The mathematical framework of the method is presented. Experimental procedures are described and results are discussed based on applying this method to the TRIUMF ECR ion source to examine the variation of the extracted beam emittance and brightness with the geometry of the extraction electrode system.     

阴极真空弧沉积中靶室第二阳极作用对系统性能的影响

介绍了阴极真空弧沉积中 ,弧源在阴极接地和阳极接地两种不同工作状态下的工作特性。发现阳极接地时 ,因沉积靶室入口法兰的第二阳极作用 ,聚焦磁场对弧源放电稳定性的影响不如阴极接地时明显。因此可以加较高的聚焦磁场 ,从而获得流强较高和较稳定的沉积等离子体束