Vacuum Technology Practice for Scientific Instruments Практика вакуумной технологии для научных инструментовГод: 2008 Автор: Dr. Nagamitsu Yoshimura / Нагомитсу Йошимура Издательство: Springer ISBN: 978-3-540-74432-0, 978-3-540-74433-7 Язык: АнглийскийФормат: PDF Качество: Изначально компьютерное (eBook) Количество страниц: 359Описание: Nanotechnology has reached a level where almost every new development and even every new product uses features of nanoscopic properties of materials. As a consequence, an enormous amount of scientific instruments is used in order to synthesize and analyze new structures and materials. Due to the surface sensitivity of such materials, many of these instruments require ultrahigh vacuum that has to be provided under extreme conditions like very high voltages. In this book, Yoshimura provides a review of the UHV related development during the last decades. His very broad experience in the design enables him to present us this detailed reference. After a general description how to design UHV systems, he covers all important issue in detail, like pumps, outgasing, Gauges, and Electrodes for high voltages. Thus, this book serves as reference for everybody using UVH in his scientific equipment.Обзор последних достижений технологий сверхвысокого вакуумаОпубликовано группой
Примеры страниц
Оглавление
1 Designing of Evacuation Systems ................................ 1
SelectionofPumpingSpeed ...................................... 2
Pumping-downCharacteristics ............................... 2
Steady-StateEvacuation..................................... 3
Roughing System .......................................... 3
BackstreamingofRPOilVapor ................................... 4
BackstreamingofDPOilVapor ................................... 6
OverloadinHigh-VacuumEvacuationSystems ...................... 8
DPIn-SeriesSystem............................................. 14
UltrahighVacuumElectronMicroscopes............................ 27
Know-how Technology in Designing UHV Evacuation Systems . . . 31
References..................................................... 32
2 Vacuum Pumps ................................................ 35
MechanicalPumps .............................................. 35
DiffusionPumps................................................ 38
TurbomolecularPumps .......................................... 41
DryVacuumPumps ............................................. 45
Cryopumps . ................................................... 51
VaporPressuresforGases ........................................ 55
SputterIonPumps .............................................. 56
NoblePumpsforInertGases...................................... 60
GetterPumps................................................... 68
Titanium-SublimationPumps ................................ 68
Non-EvaporableGetter(NEG)Pumps ......................... 69
Methods for Measuring Pumping Speeds ............................ 70
OrificeMethod............................................. 70
Three-GaugeMethod (Pipe Method) .......................... 71
Three-Point Pressure Method (3PP Method) . . . ................. 72
References..................................................... 76 3 Simulation of Pressures in High-Vacuum Systems .................. 85
ConventionalCalculationofSystemPressures ....................... 85
3AVacuumCircuits ............................................. 87
BasicConceptofVacuumCircuits ............................ 87
DesigningofVacuumCircuits................................ 89
SimulationofPressures ..................................... 91
Resistor-NetworkSimulationMethod.......................... 91
MatrixCalculationofPressures............................... 94
3B Molecular-Flow Conductance . . ................................108
Conductance ..............................................108
Transmission Probability ....................................109
3CGas-FlowPatterns............................................117
References.....................................................119
4 Outgassing ....................................................123
ProcessofOutgassing ...........................................123
Diffusion .................................................124
Recombination-limitedOutgassing............................134
DataofOutgassing..............................................136
StainlessSteel .............................................136
Electro-polishingandVacuumFiring ..........................137
Aluminum Alloy, Copper and Titanium . . ......................147
Permeation Through Elastomer Seals ..........................148
Evaporation ...............................................156
Methods for Measuring Outgassing Rates ...........................157
DifferentialPressure-riseMethod[4-41] .......................159
Variable ConductanceMethod [4-43] ..........................161
ConductanceModulation Method [4-44] . ......................164
Two-Point Pressure Method and One-Point Pressure Method [4-45] 167
References.....................................................168
5 Phenomena Induced by Electron Irradiation ......................175
5AElectron/PhotonStimulatedDesorption(ESD/PSD) ...............176
5BPolymerizationofHydrocarbonMolecules.......................182
TransportofHydrocarbonMoleculesinHighVacuum............182
TransportofHydrocarbonMoleculesinUltrahighVacuum........185
Materials to be Polymerized by Electron Beam Irradiation . .......192
5C Darkening in Secondary Electron Images in SEM .................195
5DEtchingofCarbonaceousSpecimens ............................198
References.....................................................199
6 Vacuum Gauges ................................................205
MechanicalGauges..............................................207
CapacitanceManometer.....................................207
Thermal Conductivity Gauges . ....................................209
PiraniGauge ..............................................209
ViscosityGauges................................................211
SpinningRotorGauge ......................................211
Crystal Oscillation Gauge . . . . ................................214
IonizationGauges...............................................217
PenningGauge.............................................217
SputterIonPumpasaPressureIndicator.......................220
Bayard-AlpertIonizationGauge ..............................221
ExtractorGauge............................................228
Hot-Cathode Magnetron Ionization Gauge . .....................231
Cold-Cathode Ionization Gauge for UHV ......................232
MagneticSector[6-24]......................................234
QuadrupoleMass-Filter [6-24] ...............................236
MassSpectraCrackingPatterns...............................238
Outgassing from Ionization Gauges with Incandescent Filaments . . . 239
Gas Species Emitted from Ionization Gauges with Incandescent
Filaments .................................................244
NewGaugesforMeasuringExtremeHighVacuum..............247
References.....................................................257
7 Microdischarges in High Vacuum ................................265
7A Microdischarges over Insulator Surfaces . . . ......................266
Factors ...................................................266
Charging of Dielectric Surfaces . . . . ...........................266
Gas Molecules on Insulator Surfaces ..........................275
TripleJunction.............................................278
Surface Flashover in SF6 Gas ................................280
Review ...................................................281
7BMicrodischargesbetweenHigh-VoltageElectrodes ................282
Anode-InitiationMechanism . ................................282
Ion-ExchangeProcessandTotal-VoltageEffect .................286
Projection (Whisker) on Cathode . . ...........................291
Gas Molecules on Electrode Surfaces ..........................291
Ar-GlowConditioning ......................................292
High-VoltageConditioning(HVC) ............................293
ConditioningEffect.........................................294
Review ...................................................296
References.....................................................296
8 Emitters for Fine Electron Probes ................................301
Keywords......................................................301
8A W FE Emitter . ..............................................304
Characteristics.............................................304
Remolding ................................................306
EmissionNoise ............................................312
Build-upTreatment.........................................317
FE-Initiated Vacuum Arc ....................................318
Morphological Changes of Tip ...............................320
FE-Related Technology .....................................321
Review ...................................................324
8B ZrO/W Emitter ..............................................325
Characteristics.............................................325
SurfaceGeometry ..........................................326
Properties.................................................329
8C LaB6 Emitter . . ..............................................332
Characteristics.............................................332
Mounting Methods .........................................333
MaterialLoss..............................................338
Properties.................................................340
Review ...................................................340
8D Other FE Emitters . . ..........................................341
References.....................................................341
Index .............................................................345
