Ian G. Brown

Bio: Ian G. Brown is an academic researcher from Lawrence Berkeley National Laboratory. The author has contributed to research in topics: Vacuum arc & Ion implantation. The author has an hindex of 52, co-authored 446 publications receiving 11662 citations. Previous affiliations of Ian G. Brown include Center for Advanced Materials & Russian Academy of Sciences.

The Physics and technology of ion sources

Abstract: PrefaceList of Contributors1 Introduction (Ian Brown)2 Plasma Physics (Ian Brown)21 Introduction22 Basic Plasma Parameters221 Particle Density222 Fractional Ionization223 Particle Temperature224 Particle Energy and Velocity225 Collisions23 The Plasma Sheath231 Debye Length232 Charge Neutrality233 Plasma Oscillations24 Magnetic Field Effects241 Gyro Orbits242 Gyro Frequencies243 Magnetic Confinement244 Magnetic and Plasma Pressure25 Ionization251 Electron Impact Ionization252 Multiple Ionization253 Photoionization254 Ion Impact Ionization255 Negative Ions256 Field Ionization3 Elementary Ion Sources (Ian Brown)31 Introduction32 Terminology33 The Quintessential Ion Source34 Ion Beam Formation35 Ion Beam Parameters36 An Example37 Conclusion4 Computer Simulation of Extraction (Peter Spdtke)41 Introduction42 Positive Ion Sources421 Filament Driven Cusp Sources422 Duoplasmatrons and Duopigatrons423 Vacuum Arc Ion Sources424 Laser Ion Sources425 ECR Ion Sources426 Penning Ion Sources43 Negative Ion and Electron Sources431 Hot Cathode Electron Sources432 Plasma Electron Sources433 H- Sources44 Conclusion5 Ion Extraction (Ralph Hollinger)51 Introduction52 Fundamentals of Ion Beam Formation in the Extraction System53 Beam Quality54 Sophisticated Treatment of Ion Beam Formation in the Extraction System55 Multi-Aperture Extraction Systems56 Starting Conditions6 Beam Transport (Peter Spdtke and Ralph Hollinger)61 Introduction611 Drift612 Extraction System and Acceleration Gap613 Low Energy Beam Line62 Current Effects63 Space-Charge Compensation631 Residual Gas Collisions632 Sputtering633 Preserving Space Charge Compensation634 Influence of Space Charge Compensation64 A LEBT System for the Future Proton Linac at GSI641 Compound System642 Pentode or Two-Gap System643 Triode System and DCPost-A cceleration644 Discussion7 High Current Gaseous Ion Sources (Nikolai Gavrilov)71 Introduction72 Basic Types of High Current Ion Sources721 Filament Driven Ion Sources722 High-Frequency Ion Sources723 Cold Cathode Ion Sources73 Conclusion8 Freeman and Bernas Ion Sources (Marvin Farley, Peter Rose, and Geoffrey Ryding)81 Introduction82 The Freeman Ion Source83 The Bernas Ion Source84 Further Discussion of the Source Plasma841 Plasma and Sheath Potentials842 Effect of Sputtering on the Plasma843 Ion Heating of the Cathode and Anticathode in the Bernas Source844 Current Balance in the Freeman Source845 Current Balance in the Bernas Source85 Control Systems851 Freeman and Bernas Controls852 Bernas Indirectly Heated Cathode86 Lifetime and Maintenance Issues861 Use of BF3862 Use of PH3, AsH3, P4, and As4863 Use of Sb, Sb2O3, and SbF3864 Use of SiF4 and GeF4865 General Guidelines for the Use of Other Organic and Inorganic Compounds866 Electrode Cleaning and Maintenance867 Insulator Cleaning and Maintenance9 Radio-Frequency Driven Ion Sources (Ka-Ngo Leung)91 Introduction92 Capacitively Coupled RF Sources93 Inductively Coupled RF Sources931 Source Operation with an External RF Antenna932 Multicusp Source Operation with Internal RF Antenna933 Increasing the Ion Beam Brightness of a Multicusp RF Source with Internal Antenna934 Multicusp Source Operation with External RF Antenna94 Applications of RF Ion Sources10 Microwave Ion Sources (Noriyuki Sakudo)101 Introduction102 Microwave Plasma in Magnetic Fields1021 Plasma Parameter Changes due to Magnetic Field and Microwave Frequency1022 High Density Plasma at Off-Resonance103 Some Practical Ion Source Considerations1031 Microwave Impedance Matching to the Plasma1032 High Current Ion Beams Extracted from an Off-Resonance Microwave Ion Source104 Versatility of Beam Extraction1041 Large Cross Sectional Beam formed by a Multi-Aperture Extractor1042 Slit-Shaped Beam for Ion Implantation1043 Further Improvements in Slit-Shaped Beams1044 Compact Microwave Ion Sources105 Diversity of Available Ion Species106 Microwave Ion Sources for Commercial Implanters1061 Semiconductor Device Fabrication1062 SOI Wafer Fabrication107 Conclusion11 ECR Ion Sources (Daniela Leitner and Claude Lyneis)111 Introduction112 Brief History of the Development of ECR Ion Sources113 The LBNL ECR Ion Sources1131 The AECR-U Ion Source1132 The VENUS ECR Ion Source114 Physics and Operation of ECR Ion Sources1141 Electron Impact Ionization1142 Charge Exchange1143 Plasma Confinement1144 ECR Heating1145 Gas Mixing115 Design Considerations116 Microwave and Magnetic Field Technologies117 Metal Ion Beam Production1171 Direct Insertion1172 Sputtering1173 Gaseous or Volatile Compounds (MIVOC Method)1174 External Furnaces (Ovens)1175 Efficiencies118 Ion Beam Extraction from ECR Ion Sources1181 Influence of Magnetic Field and Ion Temperature on the Extracted Ion Beam Emittance1182 Influence of Plasma Confinement on Beam Emittance119 Conclusion12 Laser Ion Sources (Boris Sharkov)121 Introduction122 Basics of Laser Plasma Physics123 General Description1231 Laser Characteristics1232 Target Illumination System1233 Target Ensemble1234 Pulse Width and Target-Extractor Separation1235 Extraction System1236 Low Energy Beam Transport Line (LEBT)124 Beam Parameters1241 Current Profile1242 Charge State Distribution1243 Beam Emittance1244 Pulse Stability and Source Lifetime125 Sources at Accelerators1251 The LIS at ITEP-TWAC1252 The LIS at CERN1253 The LIS at JINR Dubna126 Other Operating Options1261 High Current, Low Charge State Mode1262 Influence of Magnetic Field on the Laser Ion Source Plasma127 Conclusion13 Vacuum Arc Ion Sources (Efim Oks and Ian Brown)131 Introduction132 Background133 Vacuum Arc Plasma Physics134 Principles of Operation135 Beam Parameters1351 Beam Current1352 Beam Profile, Divergence and Emittance1353 Beam Composition1354 Beam Noise, Pulse Stability, and Lifetime136 Recent Improvements in Parameters and Performance1361 Enhancement of Ion Charge States1362 Alternative Triggering of the Vacuum Arc1363 Reduction in Ion Beam Noise and Increased Pulse Stability1364 Generation of Gaseous Ions137 Source Embodiments1371 LBNL Mevva Sources1372 HCEI Titan Sources1373 NPI Raduga Sources1374 GSI Varis Sources1375 Other Versions and Variants138 Conclusion14 Negative Ion Sources (Junzo Ishikawa)141 Introduction142 Surface Effect Negative Ion Sources1421 Negative Ion Production by Surface Effect1422 Surface Effect Light Negative Ion Sources1423 Surface Effect Heavy Negative Ion Sources143 Volume Production Negative Ion Sources1431 Negative Ion Formation by Volume Production1432 History of Source Development1433 Recent Volume Production Negative Ion Sources144 Charge Transfer Negative Ion Sources1441 Negative Ion Production by Charge Transfer1442 History of Charge Transfer Negative Ion Sources145 Conclusion15 Ion Sources for Heavy Ion Fusion (Joe Kwan)151 Introduction1511 Heavy Ion Beam Driven Inertial Fusion1512 HIF Ion Source Requirements152 Beam Extraction and Transport1521 Scaling Laws for Beam Extraction and Transport1522 Large Beam vs Multiple Small Beamlets153 Surface Ionization Sources1531 Contact Ionizers1532 Aluminosilicate Sources1533 Surface Ionization Sources for HIF154 Gas Discharge Ion Sources for HIF155 Pulsed Discharge Sources1551 Metal Vapor Vacuum Arc Sources for HIF1581 Laser Ion Sources for HIF156 Negative Ion Sources for HIF157 HIF Injector Designs1571 Large Diameter Source Approach1572 Merging Multiple Beamlets Approach158 Conclusion16 Giant Ion Sources for Neutral Beams (Yasuhiko Takeiri)161 Introduction162 Large Volume Plasma Production1621 Bucket Plasma Sources with Multi-Cusp Magnetic Field1622 Plasma Modeling1623 Atomic Fraction163 Large Area Beam Extraction and Acceleration1631 Electrode Systems for Large Area Beams1632 Beamlet Steering164 Giant Positive Ion Sources165 Giant Negative Ion Sources1651 Operational Principles of Negative Ion Sources1652 Negative Ion Extraction and Acceleration1653 Giant Negative Ion Sources166 Future Directions of DevelopmentAppendicesAppendix 1: Physical ConstantsAppendix 2: Some Plasma ParametersAppendix 3: Table of the ElementsIndex

Vacuum Arc Ion Sources

Abstract: The vacuum arc is a rich source of highly ionized metal plasma that can be used to make a high current metal ion source. Vacuum arc ion sources have been developed for a range of applications including ion implantation for materials surface modification, particle accelerator injection for fundamental nuclear physics research, and other fundamental and applied purposes. The beam parameters can be attractive, and the source has provided a valuable addition to the spectrum of ion sources available to the experimenter. Beams have been produced from over 50 of the solid metals of the periodic table, with mean ion energy up to several hundred keV and with beam current up to several amperes. Typically the source is repetitively pulsed with pulse length of order a millisecond and duty cycle of order 1%, and operation of a dc embodiment has been demonstrated. Here the source fundamentals and operation are reviewed, the source and beam characteristics summarized, and some applications examined.

Nanoindentation and nanoscratching of hard carbon coatings for magnetic disks

Abstract: Nanoindentation and nanoscratching experiments have been performed to assess the mechanical properties of several carbon thin films with potential application as wear resistant coatings for magnetic disks. These include three hydrogenated-carbon films prepared by sputter deposition in a H{sub 2}/Ar gas mixture (hydrogen contents of 20, 34, and 40 atomic %) and a pure carbon film prepared by cathodic-arc plasma techniques. Each film was deposited on a silicon substrate to thickness of about 300 run. The hardness and elastic modulus were measured using nanoindentation methods, and ultra-low load scratch tests were used to assess the scratch resistance of the films and measure friction coefficients. Results show that the hardness, elastic modulus, and scratch resistance of the 20 and 34% hydrogenated films are significantly greater than the 40% film, thereby showing that there is a limit to the amount of hydrogen producing beneficial effects. The cathodic-arc film, with a hardness of greater than 59 GPa, is considerably harder than any of the hydrogenated films and has a superior scratch resistance.

Hardness, elastic modulus, and structure of very hard carbon films produced by cathodic‐arc deposition with substrate pulse biasing

Abstract: The hardness, elastic modulus, and structure of several amorphous carbon films on silicon prepared by cathodic‐arc deposition with substrate pulse biasing have been examined using nanoindentation, energy loss spectroscopy (EELS), and cross‐sectional transmission electron microscopy. EELS analysis shows that the highest sp3 contents (85%) and densities (3.00 g/cm3) are achieved at incident ion energies of around 120 eV. The hardness and elastic modulus of the films with the highest sp3 contents are at least 59 and 400 GPa, respectively. These values are conservative lower estimates due to substrate influences on the nanoindentation measurements. The films are predominantly amorphous with a ∼20 nm surface layer which is structurally different and softer than the bulk.

High current ion source

Abstract: An ion source utilizing a cathode and anode for producing an electric arc therebetween. The arc is sufficient to vaporize a portion of the cathode to form a plasma. The plasma leaves the generation region and expands through another regon. The density profile of the plasma may be flattened using a magnetic field formed within a vacuum chamber. Ions are extracted from the plasma to produce a high current broad on beam.

I and i

Abstract: There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality. Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

Nonaqueous liquid electrolytes for lithium-based rechargeable batteries.

Abstract: 2.1. Solvents 4307 2.1.1. Propylene Carbonate (PC) 4308 2.1.2. Ethers 4308 2.1.3. Ethylene Carbonate (EC) 4309 2.1.4. Linear Dialkyl Carbonates 4310 2.2. Lithium Salts 4310 2.2.1. Lithium Perchlorate (LiClO4) 4311 2.2.2. Lithium Hexafluoroarsenate (LiAsF6) 4312 2.2.3. Lithium Tetrafluoroborate (LiBF4) 4312 2.2.4. Lithium Trifluoromethanesulfonate (LiTf) 4312 2.2.5. Lithium Bis(trifluoromethanesulfonyl)imide (LiIm) and Its Derivatives 4313

Diamond-like amorphous carbon

Abstract: Diamond-like carbon (DLC) is a metastable form of amorphous carbon with significant sp3 bonding. DLC is a semiconductor with a high mechanical hardness, chemical inertness, and optical transparency. This review will describe the deposition methods, deposition mechanisms, characterisation methods, electronic structure, gap states, defects, doping, luminescence, field emission, mechanical properties and some applications of DLCs. The films have widespread applications as protective coatings in areas, such as magnetic storage disks, optical windows and micro-electromechanical devices (MEMs).

Surface modification of titanium, titanium alloys, and related materials for biomedical applications

Abstract: Titanium and titanium alloys are widely used in biomedical devices and components, especially as hard tissue replacements as well as in cardiac and cardiovascular applications, because of their desirable properties, such as relatively low modulus, good fatigue strength, formability, machinability, corrosion resistance, and biocompatibility. However, titanium and its alloys cannot meet all of the clinical requirements. Therefore, in order to improve the biological, chemical, and mechanical properties, surface modification is often performed. This article reviews the various surface modification technologies pertaining to titanium and titanium alloys including mechanical treatment, thermal spraying, sol–gel, chemical and electrochemical treatment, and ion implantation from the perspective of biomedical engineering. Recent work has shown that the wear resistance, corrosion resistance, and biological properties of titanium and titanium alloys can be improved selectively using the appropriate surface treatment techniques while the desirable bulk attributes of the materials are retained. The proper surface treatment expands the use of titanium and titanium alloys in the biomedical fields. Some of the recent applications are also discussed in this paper.