Handbook of Vacuum Technology E-Book

• Herausgeber: Wiley-VCH
• Kategorie: Fachliteratur
• Sprache: Englisch

Seitenzahl: 1522

Veröffentlichungsjahr: 2016

Beschreibung

This comprehensive, standard work has been updated to remain an important resource for all those needing detailed knowledge of the theory and applications of vacuum technology.
The text covers the existing knowledge on all aspects of vacuum science and technology, ranging from fundamentals to components and operating systems. It features many numerical examples and illustrations to help visualize the theoretical issues, while the chapters are carefully cross-linked and coherent symbols and notations are used throughout the book. The whole is rounded off by a user-friendly appendix of conversion tables, mathematical tools, material related data, overviews of processes and techniques, equipment-related data, national and international standards, guidelines, and much more.
As a result, engineers, technicians, and scientists will be able to develop and work successfully with the equipment and environment found in a vacuum.

Leseprobe

Contents

Cover

Title Page

Copyright

Preface

Chapter 1: The History of Vacuum Science and Vacuum Technology

References

Further Reading

Chapter 2: Applications and Scope of Vacuum Technology

References

Chapter 3: Gas Laws and Kinetic Theory of Gases

3.1 Description of the Gas State

3.2 Kinetic Theory of Gases

3.3 Transport Properties of Gases

3.4 Real Gases

3.5 Vapors

References

Comprehensive general treatments of the subject

Chapter 4: Gas Flow

4.1 Types of Flows and Definitions

4.2 Inviscid Viscous Flow and Gas Dynamics

4.3 Frictional–Viscous Flow through a Tube

4.4 Molecular Flow under High-Vacuum and Ultrahigh-Vacuum Conditions

4.5 Flow throughout the Entire Pressure Range

4.6 Flow with Temperature Difference, Thermal Effusion, and Transpiration

4.7 Measuring Flow Conductances

References

Further Reading

Chapter 5: Analytical and Numerical Calculations of Rarefied Gas Flows

5.1 Main Concepts

5.2 Methods of Calculations of Gas Flows

5.3 Velocity Slip and Temperature Jump Phenomena

5.4 Momentum and Heat Transfer through Rarefied Gases

5.5 Flows Through Long Pipes

5.6 Flow Through an Orifice

5.7 Modeling of Holweck Pump

5.8 Appendix A

References

Chapter 6: Sorption and Diffusion

6.1 Sorption Phenomena and the Consequences, Definitions, and Terminology

6.2 Adsorption and Desorption Kinetics

6.3 Absorption, Diffusion, and Outgassing

6.4 Permeation

References

Further Reading

Chapter 7: Positive Displacement Pumps

7.1 Introduction and Overview

7.2 Oscillating Positive Displacement Pumps

7.3 Single-Shaft Rotating Positive Displacement Pumps

7.4 Twin-Spool Rotating Positive Displacement Pumps

7.5 Specific Properties of Oil-Sealed Positive Displacement Pumps

7.6 Basics of Positive Displacement Pumps

7.7 Operating and Safety Recommendations

7.8 Specific Accessories for Positive Displacement Pumps

References

Further Reading on Positive Displacement Pumps

Chapter 8: Condensers

8.1 Condensation Processes Under Vacuum

8.2 Condenser Designs

8.3 Integrating Condensers into Vacuum Systems

8.4 Calculation Examples

References

Chapter 9: Jet and Diffusion Pumps

9.1 Introduction and Overview

9.2 Liquid Jet Vacuum Pumps

9.3 Steam Jet Vacuum Pumps

9.4 Diffusion Pumps

9.5 Diffusion Pumps Versus Vapor Jet Pumps

References

Chapter 10: Molecular and Turbomolecular Pumps

10.1 Introduction

10.2 Molecular Pumps

10.3 Molecular and Regenerative Drag Pump Combination1

10.4 Physical Fundamentals of Turbomolecular Pump Stages

10.5 Turbomolecular Pumps

10.6 Performance Characteristics of Turbomolecular Pumps

10.7 Operation and Maintenance of Turbomolecular Pumps

10.8 Applications

References

Chapter 11: Sorption Pumps

11.1 Introduction

11.2 Adsorption Pumps

11.3 Getter

11.4 Ion Getter Pumps

11.5 Orbitron Pumps

References

Further Reading

Chapter 12: Cryotechnology and Cryopumps

12.1 Introduction

12.2 Methods of Refrigeration

12.3 Working Principles of Cryopumps

12.4 Design of Cryopumps

12.5 Characteristics of a Cryopump

12.6 Application Examples

References

Chapter 13: Total Pressure Vacuum Gauges

13.1 Introduction

13.2 Mechanical Vacuum Gauges

13.3 Spinning Rotor Gauges (Gas-Friction Vacuum Gauges)

13.4 Direct Electric Pressure Measuring Transducers

13.5 Thermal Conductivity Vacuum Gauges

13.6 Thermal Mass Flowmeters

13.7 Ionization Gauges

13.8 Combined Vacuum Gauges

References

Chapter 14: Partial Pressure Vacuum Gauges and Leak Detectors

14.1 Introduction

14.2 Partial Pressure Analysis by Mass Spectrometry

14.3 Partial Pressure Measurement Using Optical Methods

14.4 Leak Detectors

References

Chapter 15: Calibrations and Standards

15.1 Introduction

15.2 Calibration of Vacuum Gauges

15.3 Calibrations of Residual Gas Analyzers

15.4 Calibration of Test Leaks

15.5 Standards for Determining Characteristics of Vacuum Pumps

References

Chapter 16: Materials

16.1 Requirements and Overview of Materials

16.2 Materials for Vacuum Technology [11]

16.3 Gas Permeability and Gas Emissions of Materials

References

Further Reading

Chapter 17: Vacuum Components, Seals, and Joints

17.1 Introduction

17.2 Vacuum Hygiene

17.3 Joining Technologies in Vacuum Technology

17.4 Components

Abbreviations

References

Chapter 18: Operating Vacuum Systems

18.1 Electronic Integration of Vacuum Systems

18.2 Calculation of Vacuum Systems

18.3 Pressure Control

18.4 Techniques for Operating Low-Vacuum Systems

18.5 Techniques for Operating Fine-Vacuum Systems

18.6 Techniques for Operating High-Vacuum Systems

18.7 Techniques for Operating Ultrahigh-Vacuum Systems [11]

References

Chapter 19: Methods of Leak Detection

19.1 Overview

19.2 Properties of Leaks

19.3 Overview of Leak-Detection Methods (See also EN 1779)

19.4 Leak Detection Using Helium Leak Detectors

19.5 Leak Detection with Other Tracer Gases

19.6 Industrial Tightness Testing of Mass-Production Components

References

Further reading

Appendix

Index

Directory of Products and Suppliers

End User License Agreement

List of Tables

Table 3.1

Table 3.2

Table 3.3

Table 3.4

Table 3.5

Table 3.6

Table 3.7

Table 3.8

Table 4.1

Table 4.2

Table 4.3

Table 4.4

Table 4.5

Table 4.6

Table 5.1

Table 5.2

Table 5.A.1

Table 5.A.2

Table 5.3

Table 5.4

Table 5.A.3

Table 5.A.4

Table 5.A.5

Table 5.A.6

Table 5.5

Table 6.1

Table 6.2

Table 6.3

Table 6.4

Table 6.5

Table 7.1

Table 7.2

Table 8.1

Table 8.2

Table 9.1

Table 9.2

Table 9.3

Table 9.4

Table 10.1

Table 11.1

Table 11.2

Table 11.3

Table 11.4

Table 11.5

Table 11.6

Table 11.7

Table 11.8

Table 12.1

Table 12.2

Table 12.3

Table 12.4

Table 12.5

Table 12.6

Table 13.1

Table 13.2

Table 13.3

Table 13.4

Table 13.5

Table 13.6

Table 14.1

Table 14.2

Table 14.3

Table 15.1

Table 15.2

Table 15.3

Table 15.4

Table 15.5

Table 15.6

Table 15.7

Table 15.8

Table 16.1

Table 16.2

Table 16.3

Table 16.4

Table 16.5

Table 16.6

Table 16.7

Table 17.1

Table 17.2

Table 17.3

Table 17.4

Table 17.5

Table 17.6

Table 17.7

Table 17.8

Table 17.9

Table 17.10

Table 17.11

Table 17.12

Table 17.13

Table 18.1

Table 18.2

Table 18.3

Table 18.4

Table 18.5

Table 19.1

Table 19.2

Table 19.3

Table A.1

Table A.2

Table A.3

Table A.4

Table A.5

Table A.6

Table A.7

Table A.8

Table A.9

Table A.10

Table A.11

Table A.12

Table A.13

Table A.14

Table A.15

Table A.16

Table A.17

Table A.18

Table A.19

Table A.20

Table A.21

Table A.22

Table A.23

List of Illustrations

Figure 1.1

Figure 1.2

Figure 1.3

Figure 1.4

Figure 1.5

Figure 1.6

Figure 1.7

Figure 1.8

Figure 1.9

Figure 1.10

Figure 1.11

Figure 1.12

Figure 1.13

Figure 1.14

Figure 1.15

Figure 1.16

Figure 1.17

Figure 2.1

Figure 2.2

Figure 2.3

Figure 2.4

Figure 2.5

Figure 2.6

Figure 3.1

Figure 3.2

Figure 3.3

Figure 3.4

Figure 3.5

Figure 3.6

Figure 3.7

Figure 3.8

Figure 3.9

Figure 3.10

Figure 3.11

Figure 3.12

Figure 3.13

Figure 3.14

Figure 3.15

Figure 3.16

Figure 3.17

Figure 3.18

Figure 3.19

Figure 3.20

Figure 3.21

Figure 3.22

Figure 3.23

Figure 3.24

Figure 3.25

Figure 3.26

Figure 4.1

Figure 4.2

Figure 4.3

Figure 4.4

Figure 4.5

Figure 4.6

Figure 4.7

Figure 4.8

Figure 4.9

Figure 4.10

Figure 4.11

Figure 4.12

Figure 4.13

Figure 4.14

Figure 4.15

Figure 4.16

Figure 4.17

Figure 4.18

Figure 4.19

Figure 4.20

Figure 4.21

Figure 4.22

Figure 4.23

Figure 4.24

Figure 4.25

Figure 4.26

Figure 4.27

Figure 4.28

Figure 4.29

Figure 4.30

Figure 4.31

Figure 4.32

Figure 4.33

Figure 4.34

Figure 4.35

Figure 4.36

Figure 4.37

Figure 4.38

Figure 4.39

Figure 4.40

Figure 4.41

Figure 4.42

Figure 4.43

Figure 4.44

Figure 4.45

Figure 4.46

Figure 4.47

Figure 4.48

Figure 4.49

Figure 4.50

Figure 4.51

Figure 4.52

Figure 4.53

Figure 4.54

Figure 4.55

Figure 4.56

Figure 5.1

Figure 5.2

Figure 5.3

Figure 5.4

Figure 5.5

Figure 5.6

Figure 5.7

Figure 5.8

Figure 5.9

Figure 5.10

Figure 5.11

Figure 5.12

Figure 5.13

Figure 5.14

Figure 5.15

Figure 5.16

Figure 5.17

Figure 5.18

Figure 5.19

Figure 5.20

Figure 5.21

Figure 5.22

Figure 5.23

Figure 5.24

Figure 5.25

Figure 5.26

Figure 5.27

Figure 5.28

Figure 5.29

Figure 5.30

Figure 5.31

Figure 5.32

Figure 5.33

Figure 5.34

Figure 5.35

Figure 5.36

Figure 5.37

Figure 5.38

Figure 6.1

Figure 6.2

Figure 6.3

Figure 6.4

Figure 6.5

Figure 6.6

Figure 6.7

Figure 6.8

Figure 6.9

Figure 6.10

Figure 6.11

Figure 6.12

Figure 6.13

Figure 7.1

Figure 7.2

Figure 7.3

Figure 7.4

Figure 7.5

Figure 7.6

Figure 7.7

Figure 7.8

Figure 7.9

Figure 7.10

Figure 7.11

Figure 7.12

Figure 7.13

Figure 7.14

Figure 7.15

Figure 7.16

Figure 7.17

Figure 7.18

Figure 7.19

Figure 7.20

Figure 7.21

Figure 7.22

Figure 7.23

Figure 7.24

Figure 7.25

Figure 7.26

Figure 7.27

Figure 7.28

Figure 7.29

Figure 7.30

Figure 7.31

Figure 7.32

Figure 7.33

Figure 7.34

Figure 7.35

Figure 7.36

Figure 7.37

Figure 7.38

Figure 7.39

Figure 7.40

Figure 7.41

Figure 7.42

Figure 7.43

Figure 7.44

Figure 7.45

Figure 7.46

Figure 7.47

Figure 7.48

Figure 7.49

Figure 7.50

Figure 7.51

Figure 7.52

Figure 7.53

Figure 7.54

Figure 7.55

Figure 7.56

Figure 7.57

Figure 7.58

Figure 7.59

Figure 7.60

Figure 7.61

Figure 7.62

Figure 7.63

Figure 7.64

Figure 7.65

Figure 7.66

Figure 7.67

Figure 7.68

Figure 7.69

Figure 7.70

Figure 7.71

Figure 7.72

Figure 7.73

Figure 8.1

Figure 8.2

Figure 8.3

Figure 8.4

Figure 8.5

Figure 8.6

Figure 8.7

Figure 8.8

Figure 8.9

Figure 8.10

Figure 8.11

Figure 8.12

Figure 8.13

Figure 8.14

Figure 8.15

Figure 8.16

Figure 8.17

Figure 8.18

Figure 9.1

Figure 9.2

Figure 9.3

Figure 9.4

Figure 9.5

Figure 9.6

Figure 9.7

Figure 9.8

Figure 9.9

Figure 9.10

Figure 9.11

Figure 9.12

Figure 9.13

Figure 9.14

Figure 9.15

Figure 9.16

Figure 9.17

Figure 9.18

Figure 9.19

Figure 9.20

Figure 9.21

Figure 9.22

Figure 9.23

Figure 9.24

Figure 10.1

Figure 10.2

Figure 10.3

Figure 10.4

Figure 10.5

Figure 10.6

Figure 10.7

Figure 10.8

Figure 10.9

Figure 10.10

Figure 10.11

Figure 10.12

Figure 10.13

Figure 10.14

Figure 10.15

Figure 10.16

Figure 10.17

Figure 10.18

Figure 10.19

Figure 10.20

Figure 10.21

Figure 10.22

Figure 10.23

Figure 10.24

Figure 10.25

Figure 10.26

Figure 10.27

Figure 10.28

Figure 11.1

Figure 11.2

Figure 11.3

Figure 11.4

Figure 11.5

Figure 11.6

Figure 11.7

Figure 11.8

Figure 11.9

Figure 11.10

Figure 11.11

Figure 11.12

Figure 11.13

Figure 11.14

Figure 11.15

Figure 11.16

Figure 11.17

Figure 11.18

Figure 11.19

Figure 11.20

Figure 11.21

Figure 11.22

Figure 11.23

Figure 11.24

Figure 11.25

Figure 11.26

Figure 11.27

Figure 11.28

Figure 11.29

Figure 11.30

Figure 12.1

Figure 12.2

Figure 12.3

Figure 12.4

Figure 12.5

Figure 12.6

Figure 12.7

Figure 12.8

Figure 12.9

Figure 12.10

Figure 12.11

Figure 12.12

Figure 12.13

Figure 12.14

Figure 12.15

Figure 12.16

Figure 12.17

Figure 12.18

Figure 12.19

Figure 12.20

Figure 12.21

Figure 12.22

Figure 12.23

Figure 12.24

Figure 12.25

Figure 12.26

Figure 12.27

Figure 12.28

Figure 12.29

Figure 12.30

Figure 12.31

Figure 13.1

Figure 13.2

Figure 13.3

Figure 13.4

Figure 13.5

Figure 13.6

Figure 13.7

Figure 13.8

Figure 13.9

Figure 13.10

Figure 13.11

Figure 13.12

Figure 13.13

Figure 13.14

Figure 13.15

Figure 13.16

Figure 13.17

Figure 13.18

Figure 13.19

Figure 13.20

Figure 13.21

Figure 13.22

Figure 13.23

Figure 13.24

Figure 13.25

Figure 13.26

Figure 13.27

Figure 13.28

Figure 13.29

Figure 13.30

Figure 13.31

Figure 13.32

Figure 13.33

Figure 13.34

Figure 13.35

Figure 13.36

Figure 13.37

Figure 13.38

Figure 13.39

Figure 13.40

Figure 13.41

Figure 13.42

Figure 13.43

Figure 13.44

Figure 13.45

Figure 13.46

Figure 13.47

Figure 13.48

Figure 13.49

Figure 13.50

Figure 13.51

Figure 13.52

Figure 13.53

Figure 13.54

Figure 13.55

Figure 13.56

Figure 13.57

Figure 13.58

Figure 13.59

Figure 13.60

Figure 13.61

Figure 13.62

Figure 13.63

Figure 13.64

Figure 13.65

Figure 13.66

Figure 13.67

Figure 13.68

Figure 13.69

Figure 13.70

Figure 13.71

Figure 13.72

Figure 14.1

Figure 14.2

Figure 14.3

Figure 14.4

Figure 14.5

Figure 14.6

Figure 14.7

Figure 14.8

Figure 14.9

Figure 14.10

Figure 14.11

Figure 14.12

Figure 14.13

Figure 14.14

Figure 14.15

Figure 14.16

Figure 14.17

Figure 14.18

Figure 14.19

Figure 14.20

Figure 14.21

Figure 14.22

Figure 14.23

Figure 14.24

Figure 14.25

Figure 14.26

Figure 14.27

Figure 14.28

Figure 14.29

Figure 14.30

Figure 14.31

Figure 14.32

Figure 14.33

Figure 14.34

Figure 14.35

Figure 14.36

Figure 14.37

Figure 14.38

Figure 15.1

Figure 15.2

Figure 15.3

Figure 15.4

Figure 15.5

Figure 15.6

Figure 15.7

Figure 15.8

Figure 15.9

Figure 15.10

Figure 15.11

Figure 15.12

Figure 15.13

Figure 15.14

Figure 15.15

Figure 15.16

Figure 15.17

Figure 15.18

Figure 15.19

Figure 15.20

Figure 15.21

Figure 15.22

Figure 15.23

Figure 15.24

Figure 15.25

Figure 15.26

Figure 15.27

Figure 16.1

Figure 16.2

Figure 16.3

Figure 16.4

Figure 16.5

Figure 16.6

Figure 16.7

Figure 16.8

Figure 17.1

Figure 17.2

Figure 17.3

Figure 17.4

Figure 17.5

Figure 17.6

Figure 17.7

Figure 17.8

Figure 17.9

Figure 17.10

Figure 17.11

Figure 17.12

Figure 17.13

Figure 17.14

Figure 17.15

Figure 17.16

Figure 17.17

Figure 17.18

Figure 17.19

Figure 17.20

Figure 17.21

Figure 17.22

Figure 17.23

Figure 17.24

Figure 17.25

Figure 17.26

Figure 17.27

Figure 17.28

Figure 17.29

Figure 17.30

Figure 17.31

Figure 17.32

Figure 17.33

Figure 17.34

Figure 17.35

Figure 17.36

Figure 17.37

Figure 17.38

Figure 17.39

Figure 17.40

Figure 17.41

Figure 17.42

Figure 17.43

Figure 17.44

Figure 17.45

Figure 17.46

Figure 17.47

Figure 17.48

Figure 17.49

Figure 17.50

Figure 17.51

Figure 17.52

Figure 17.53

Figure 17.54

Figure 17.55

Figure 17.56

Figure 18.1

Figure 18.2

Figure 18.3

Figure 18.4

Figure 18.5

Figure 18.6

Figure 18.7

Figure 18.8

Figure 18.9

Figure 18.10

Figure 18.11

Figure 18.12

Figure 18.13

Figure 18.14

Figure 18.15

Figure 18.16

Figure 18.17

Figure 18.18

Figure 18.19

Figure 18.20

Figure 18.21

Figure 18.22

Figure 18.23

Figure 18.24

Figure 18.25

Figure 18.26

Figure 18.27

Figure 18.28

Figure 18.29

Figure 18.30

Figure 18.31

Figure 18.32

Figure 18.33

Figure 19.1

Figure 19.2

Figure 19.3

Figure 19.4

Figure 19.5

Figure 19.6

Figure 19.7

Figure 19.8

Figure 19.9

Figure 19.10

Figure 19.11

Figure 19.12

Figure 19.13

Figure 19.14

Figure 19.15

Figure 19.16

Figure B.1

Figure B.2

Figure B.3

Figure B.4

Figure B.5

Figure B.6

Figure B.7

Figure B.8

Figure B.9

Figure B.10

Figure B.11

Figure B.12

Figure B.13

Figure B.14

Figure B.15

Guide

Cover

Table of Contents

Begin Reading

Chapter 1

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Edited by Karl Jousten

Handbook of Vacuum Technology

Second, Completely Revised and Updated Edition

All books published by Wiley-VCH are carefully produced. Nevertheless, authors, editors, and publisher do not warrant the information contained in these books, including this book, to be free of errors. Readers are advised to keep in mind that statements, data, illustrations, procedural details or other items may inadvertently be inaccurate.

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© 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Boschstr. 12, 69469 Weinheim, Germany

All rights reserved (including those of translation into other languages). No part of this book may be reproduced in any form – by photoprinting, microfilm, or any other means – nor transmitted or translated into a machine language without written permission from the publishers. Registered names, trademarks, etc. used in this book, even when not specifically marked as such, are not to be considered unprotected by law.

Print ISBN: 978-3-527-41338-6

ePDF ISBN: 978-3-527-68825-8

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Preface

In 2008, Wiley-VCH published a translation of the ninth edition of the German handbook “Wutz – Handbook of Vacuum Technology,” named after the author of the first edition Max Wutz. This book has been a great success for five decades and the object of many requests for a translation. Since its second edition, the “Wutz – Handbook of Vacuum Technology” has become a multi-author book covering the field of vacuum science, vacuum technology, and vacuum techniques comprehensively. Since 2008, the German handbook underwent significant changes and when it could be foreseen that the English edition would run out of print, Wiley-VCH suggested to issue a second English edition “Handbook of Vacuum Technology,” which is a translation of the 11th German edition of the “Wutz – Handbook of Vacuum Technology,” published by Springer Vieweg. Chapter 17, however, received a new author and was newly written for this second English edition. Compared with the first English edition, also Chapters 10 and 12 were written by new authors while improvements were made in most of the other chapters according to the changes in techniques.

Although multi-author, the book aims to be read as a single-author work, a goal to which the present editor who himself has revised almost half of the content has stringently adhered to. The style is as uniform as possible, there are only recurrences where necessary, and the same symbols and notation are used throughout. Hence, the book has taken on textbook character, though it was originally intended to be used as a technical handbook.

The main idea of the book is to cover all aspects of vacuum science and technology in order to enable engineers, technicians, and scientists to develop and work successfully with the equipment and “environment” of vacuum. Beginners in the field of vacuum shall be able to start and experts shall be able to deepen their knowledge and find the necessary information and data to continue their work.

Despite the fact that the applications of vacuum technology are steadily increasing both quantitatively and qualitatively – note, for instance, that the next chip generation will be illuminated under vacuum by extreme ultraviolet (EUV) lithography – the number of scientists researching and teaching in the field is on a steady decline. Thus, another task for a book like this is to both preserve the knowledge of vacuum science and technology and enable self-studying in the field. For this reason, the book may be at times too introductive and simple for experts and sometimes too specialized for beginners. The reader should not be discouraged when experiencing this, but rather choose the information as his/her personal level requires. Short explanations following the title of each chapter describe the contents and may help the reader to choose the right chapter for his/her needs.

We hope that also this second edition will be helpful to all readers of English interested in a comprehensive and up-to-date overview in the field of vacuum technology including its underlying science.

Even after many people read drafts and proofs, there will always be mistakes in a book of this size. If you discover such or if you have any suggestions for improvements, please send an email to the editor ([email protected]). I will be glad to consider your suggestions in future editions.

June 2015

Karl Jousten

Berlin, Germany

1The History of Vacuum Science and Vacuum Technology

Dr. Karl Jousten

Physikalisch-Technische Bundesanstalt, Vacuum Metrology, Abbestr. 2-12, 10587, Berlin, Germany

In old Greece, before the time of Socrates, the philosophers searched for the constancy in the world, that is, what is behind the daily experience. The Greek philosopher Democritus (circa 460 to 375 BC) (Figure 1.1) assumed that the world was made up of many small and undividable particles that he called atoms (atomos, Greek: undividable). In between the atoms, Democritus presumed empty space (a kind of microvacuum) through which the atoms moved according to the general laws of mechanics. Variations in shape, orientation, and arrangement of the atoms would cause variations of macroscopic objects. Acknowledging this philosophy, Democritus, together with his teacher Leucippus, may be considered as the inventor of the concept of vacuum. For them, the empty space was the precondition for the variety of our world, since it allowed the atoms to move about and arrange themselves freely. Our modern view of physics corresponds very closely to this idea of Democritus. However, his philosophy did not dominate the way of thinking until the sixteenth century.

Figure 1.1Democritus. Bronze statue around 250 BC, National Museum in Naples.

It was Aristotle's (384 to 322 BC) philosophy that prevailed throughout the Middle Ages and until the beginning of modern times. In his book Physica [1], around 330 BC, Aristotle denied the existence of an empty space. Where there is nothing, space could not be defined. For this reason, no vacuum (Latin: empty space, emptiness) could exist in nature. According to his philosophy, nature consisted of water, earth, air, and fire. The lightest of these four elements, fire, is directed upward, whereas the heaviest, earth, downward. Additionally, nature would forbid vacuum since neither up nor down could be defined within it. Around 1300, the medieval scholastics began to speak of a horror vacui, meaning nature's fear of vacuum. Nature would abhor vacuum and wherever such a vacuum may be on the verge to develop, nature would fill it immediately.

Around 1600, however, the possibility or impossibility of an evacuated volume without any matter was a much-debated issue within the scientific–philosophical community of Italy, and later in France and Germany as well. This happened at the time when the first scientists were burnt at the stake (Bruno in 1600).

In 1613, Galileo Galilei in Florence attempted to measure the weight and density of air. He determined the weight of a glass flask containing either compressed air, air at atmospheric pressure, or water. He found a value of for the density of air (the modern value is ). This was a big step forward: air could now be considered as a substance with weight. Therefore, it could be assumed that air, in some way, could also be removed from a volume.

In 1630, Galilei was in correspondence with the Genoese scientist Baliani discussing the water supply system of Genoa. Galilei argued that, for a long time, he had been aware of the fact that the maximum height of a water column in a vertical pipe produced by a suction pump device was about 34 feet. Baliani replied that he thought this was due to the limited pressure of the atmosphere!

One can see from these examples that in Italy in the first half of the seventeenth century the ground was prepared for an experiment, which was performed in 1640 by Gasparo Berti and in 1644 by Evangelista Torricelli, a professor in Florence. The Torricelli experiment was bound to be one of the key experiments of natural sciences.

Torricelli filled a glass tube of about 1 m in length with mercury. The open end was sealed with a fingertip. The tube was then brought to an upright position with the end pointing downward sealed by the fingertip. This end was immersed in a mercury reservoir and the fingertip removed so that the mercury inside the tube was in free contact with the reservoir. The mercury column in the tube sank to a height of 76 cm, measured from the liquid surface of the reservoir. Figure 1.2 shows a drawing of the Torricellian apparatus.

Figure 1.2Torricelli's vacuum experiment in 1644. The level AB of mercury in both tubes C and D was equal, independent of the size of the additional volume E in tube D. (From Ref. [2].)

The experiment demonstrated that the space left above the mercury after turning the tube upside down was in fact a vacuum: the mercury level was independent of the volume above, and it could be filled completely with water admitted from below. This experiment was the first successful attempt to produce vacuum and subsequently convinced the scientific community. An earlier attempt by Berti who used water was less successful.

In 1646, the mathematician Pierre Petit in France informed Blaise Pascal (Figure 1.3) about Torricelli's experiment. Pascal repeated the experiment and, in addition, tried other types of liquid. He found that the maximum height was exactly inversely proportional to the used liquid's density. Pascal knew the equally famous philosopher Descartes. During a discussion in 1647, they developed the idea of air pressure measurements at different altitudes using a Torricellian tube.

Figure 1.3 Portrait of Blaise Pascal.

Pascal wrote a letter to his brother-in-law Périer and asked him to carry out the experiment on the very steep mountain Puy de Dôme, close to Périer's home. Périer agreed and on September 19, 1648 [3], he climbed the Puy de Dôme (1500 m) accompanied by several men who served to testify the results, which was common practice at the time. They recorded the height of the mercury column at various altitudes. From the foot to the top of the mountain, the difference of the mercury column's height was almost 8 cm and Pascal was very pleased: the first successful pressure measurement had been carried out! Torricelli, however, never enjoyed the triumph of the experiment based on his invention: he had died a year before.

Despite these experiments, the discussion between the plenists (no vacuum is possible in nature) and the vacuists (vacuum is possible) continued. One of the leading vacuists was Otto von Guericke, burgomaster of Magdeburg in Germany from 1645 to 1676 (Figure 1.4).

Figure 1.4 Portrait of Otto von Guericke in 1672. Engraving after a master of Cornelius Galle the Younger. (From Ref. [4].)

He was the first German scientist who gave experiments a clear priority over merely intellectual considerations when attempting to solve problems about nature.

Around 1650, Guericke tried to produce a vacuum in a water-filled, wooden cask by pumping out the water with a pump used by the fire brigade in Magdeburg. Although the cask was specially sealed, the experiment failed: the air rushed into the empty space above the water through the wood, developing a chattering noise. Consequently, Guericke ordered to build a large copper sphere, but when the air was pumped out, the sphere was suddenly crushed. Guericke correctly recognized atmospheric pressure as the cause and ascribed the weakness of the sphere to the loss of sphericity. The problem was solved by constructing a thicker and more precisely shaped sphere. After evacuating this sphere and leaving it untouched for several days, Guericke found that the air was seeping into the sphere, mainly through the pistons of the pump and the seals of the valves. To avoid this, he constructed a new pump where these parts were sealed by water, an idea still used in today's vacuum pumps, but with oil instead of water.

Guericke's third version (Figure 1.5) was an air pump, which pumped air directly out of a vessel. These pumps were capable of producing vacua in much larger volumes than Torricellian tubes.

Figure 1.5Guericke's air pump no. 3. Design for Elector Friedrich Wilhelm, 1663. (From Ref. [4].)

The word pump is still used for today's vacuum pumps, although they are actually rarefied gas compressors. This is due to the origin of the vacuum pump: the water pump used by the fire brigade in Magdeburg.

Guericke was also a very successful promoter of his own knowledge and experiments, which he used to catch attention for political purposes. In 1654, he performed several spectacular experiments for the German Reichstag in Regensburg. The most famous experiment demonstrating the new vacuum technique was displayed in Magdeburg in 1657.

Guericke used two hemispheres with a diameter of 40 cm, known as the Magdeburg hemispheres (Figure 1.6). One of the hemispheres had a valve for evacuation, and between the hemispheres, Guericke placed a leather ring soaked with wax and turpentine as seal. Teams of eight horses on either side were just barely able to separate the two hemispheres after the enclosed volume had been evacuated.

Figure 1.6 Painting of Guericke showing his experiment with the hemispheres to the German emperor, Kaiser Ferdinand III. (From Ref. [4].)

News of Guericke's experiment spread throughout Europe and his air pump can be considered as one of the greatest technical inventions of the seventeenth century, the others being the telescope, the microscope, and the pendulum clock.

The new vacuum technology brought up many interesting experiments. Most of them were performed by Guericke and Schott in Germany, by Huygens in the Netherlands, and by Boyle and Hooke in England.

Guericke showed that a bell positioned in a vacuum could not be heard; a magnetic force, however, was not influenced by the vacuum. Instead of metal, he often used glass vessels in order to make the processes in vacuum visible. For this, he used glass flasks from the pharmacist. These were called recipients, a word still used today for vacuum vessels. Guericke put a candle in a glass vessel and found that the candle extinguished slowly as evacuation proceeded. Huygens suspended a lump of butter in the center of a vacuum jar and, after evacuation, he placed a hot iron cap over the jar. In spite of the hot jar, the butter did not melt. Animals set into vacuum chambers died in a cruel manner. Guericke even put fish in a glass vessel, half filled with water. After evacuating the air above and from the water, most of the fish swelled and died.

Noble societies of the seventeenth and eighteenth century enjoyed watching experiments of this kind for amusement (Figure 1.7).

Figure 1.7 “Experiment on a bird in the air pump,” 1768, by Joseph Wright, National Gallery, London. A pet cockatoo (top center) was placed in a glass vessel and the vessel was evacuated. The lecturer's left hand controls the plug at the top of the glass globe. By opening it, he saves the life of the already dazed bird. The man below the “experimenter” stops the time until the possible death of the bird.

However, scientific experiments were performed as well during the early days of vacuum. Huygens verified that the free fall of a feather in a vacuum tube was exactly equal to that of a piece of lead. Boyle found that the product of volume and pressure was constant, while Amontons in France showed that this constant was temperature-dependent (1699).

In 1673, Huygens attempted to build an internal combustion engine using the pressure difference between the atmosphere and a vacuum to lift heavy weights (Figure 1.8). Gunpowder, together with a burning wick, is placed in container C, arranged at the lower end of cylinder AB. The violent reaction of the gunpowder drives the air out of the cylinder through the wetted leather tubes EF. Cylinder AB cools down and produces a vacuum. The tubes EF then flatten and seal, and the atmospheric pressure drives down piston D, thus lifting weight G.

Figure 1.8Huygens' explosion motor. After the explosion of gunpowder in container C, the temperature drops creating vacuum that lifts weight G. (From Ref. [3].)

During the experiments, the importance of carefully cleaned materials became obvious and it was realized that the quality of pumps would have to be improved. Engineering improvements by Hooke, Hauksbee (1670–1713), and others followed. Somewhat later, the Englishman H. A. Fleuss developed a piston pump that he named Geryk in honor of Otto von Guericke.

However, it was not until 1855 that significantly better vacua could be produced using a pump designed by Geissler in Germany. Sprengel improved this pump in 1865 and 1873 (Figures 1.9 and 1.10), which used Torricelli's principle. Ten kilograms of mercury had to be lifted up and down by hand for a pump speed of about . About 6 h of pumping action was required to evacuate a vessel of from 0.1 mmHg (13 Pa) to about ! With these pumps, for the first time, the high-vacuum regime became available. In 1879, Edison used them in his Menlo Park to evacuate the first incandescent lamps (Figure 1.11).

Figure 1.9Sprengel's first mercury pumps of 1865. A falling mercury droplet formed a piston that drove the air downward (suction ports at D and “exhaust tube”). Later, Sprengel improved the pump by adding a mechanism to recover the mercury. (From Ref. [5].)

Figure 1.10 Progress in lowest generated and measured pressures in vacuum from 1660 to 1900. (Data from Ref. [6].)

Figure 1.11Edison's production of incandescent lamps in Menlo Park in 1879. The man standing elevated pours mercury into a Sprengel pump (Figure 1.9) to evacuate an incandescent lamp.

The early scientists who produced vacuum still had no clear definition of a vacuum. They had no idea that air could consist of atoms and molecules, which in part are removed to produce a vacuum. Until 1874, the Torricellian tube was the only instrument available for measuring vacuum, and limited to about 0.5 mmHg (67 Pa). The idea of vacuum was still quite an absolute (present or not) as in the Aristotelian philosophy but it was not accepted as a measurable quantity. The gas kinetic theory by Clausing, Maxwell, Boltzmann, and others as well as the invention of the gauge by McLeod (1874), however, showed that vacuum indeed was a measurable physical quantity.

The McLeod gauge (Figure 1.12), still applied in a few laboratories today, uses Boyle's law. By compressing a known volume of gas by a known ratio to a higher pressure, which can be measured using a mercury column, the original pressure can be calculated.

Figure 1.12 Original McLeod vacuum gauge [7]. (a) Measuring port; (b) simple siphon barometer; (c) glass bulb with a volume of 48 ml and a volume tube at the upper end having identical diameter as the measuring tube (d); (f) vertical 80 cm long tube; and (g) reservoir of mercury. As soon as the mercury is lifted to the level of (e), the gas in (c) is compressed developing a height difference between (d) and the tube above (c) according to the volume ratio.

Huygens' idea of using the pressure difference between the atmosphere and a vacuum to build an engine was continued by Thomas Newcomen in the eighteenth century. He used condensed steam to create vacuum. Newcomen's engines were broadly used in England to pump water from deep mine shafts, to pump domestic water supplies, and to supply water for industrial water wheels in times of drought. His machines predate rotary steam engines by 70 years.

Another exciting development in the history of vacuum technology took place when atmospheric railways were constructed in England during the mid-nineteenth century. Since steam locomotives at the time were rather unreliable, dirty, noisy, heavy, and not able to face steep gradients, a group of imaginative engineers conceived a plan to build clean, silent, and light trains driven by the force between the atmosphere and a vacuum on the surface of a piston placed between the rails.

In 1846, Brunel built such a system on the South Devon coast of England (Figure 1.13).

Figure 1.13 Drawing of the vacuum traction tube to propel an atmospheric railway. Piston (a) slides forward due to the action of a vacuum pump positioned in front of (to the right of) the piston. (b) connects the piston with the leading wagon of the train. Wheel (c) lifts and opens the longitudinal valve (d) while wheel (e) closes it. (From Ref. [8].)

A continuous line of a cast iron tube was arranged centrally between the rails. The pressure difference of the external atmosphere on its rear and the rough vacuum on its front surface propelled a tightly fitted piston inside the tube. Huge stationary pumps placed in about 5 km intervals along the track generated the vacuum. The underside of the first railway coach was connected to a frame forming the rear end of the piston. Along the top of the tube was a slot closed by a longitudinal airtight valve, consisting of a continuous leather flap reinforced with iron framing.

An average speed of 103 km h−1 over 6 km was reported for these trains, which was breathtaking at the time. However, atmospheric railways did not prevail. Accidents with starting trains, the lack of control by the engineer on board, and the inefficiency of the longitudinal valve (e.g., rats ate through the leather sealing), among other reasons, contributed to their demise.

The large advances in physics in the second half of the nineteenth century are almost unthinkable without the aid of vacuum technology. Hauksbee already discovered gas discharges at the beginning of the eighteenth century. Significant progress, however, was only possible after the invention of the Geissler pump in 1855. Three years later, Plücker found that the glow of the glass wall during a gas discharge shifts when a magnetic field is applied. In 1860, Hittorf discovered that the rays from a cathode produce a very sharp shadow if an object is placed in between the cathode and a glass. Many scientists continued research on cathode rays, which finally led to the discovery of the electron as a component of the cathode rays by J. Thomson in 1898.

In 1895, Röntgen reported that when a discharge is pumped to less than 1 Pa, a highly penetrating radiation is produced capable of passing through air, flesh, and even thin sheets of metal. He named the beams X-rays.

In 1887, Hertz discovered the photoelectric effect under vacuum. In 1890, Ramsay and Rayleigh discovered the noble gases. All these experiments helped to understand the nature of vacuum: the increasing rarefaction of gas atoms and molecules. At the time, it became clear that any matter in nature consists of atoms.

In 1909, Knudsen [9] published a comprehensive investigation on the flow of gases through long and narrow tubes. He divided this flow into three regimes: the molecular regime at very low pressures, where the particles are so dilute that they do not interact with each other but only with the surrounding walls, the viscous regime at higher pressures, where the motion of particles is greatly influenced by mutual collisions, and an intermediate regime. This publication can be considered as the beginning of vacuum physics.

For his experiments, Knudsen used the so-called Gaede pump. Gaede, a professor at the University of Freiburg in Germany, was the most important inventor of vacuum pumps since Guericke. Gaede's pump was a rotary mercury pump (Figure 1.14), in which the Torricellian tube was wound up so that it allowed continuous pumping by rotary action. The pump was driven by an electromotor. Its pumping speed was 10 times faster than the Sprengel-type pump and produced vacua down to 1 mPa. However, it required an additional pump in series because it was able to compress the gas only up to 1/100 of atmospheric pressure.

Figure 1.14Gaede's mercury rotation pump. R indicates the position of the suction port. (With kind permission of the Gaede Foundation at Oerlikon Leybold GmbH, Cologne, Germany.)

The sliding vane rotary vacuum pump was developed between 1904 and 1910, based on an idea of aristocrat Prince Rupprecht, which dated back to 1657 [10]. Gaede optimized these pumps in 1935 by inventing the gas ballast, which allowed pumping condensable gases as well.

Gaede carefully studied Knudsen's work, and at a meeting of the German Physical Society in 1912 introduced his first molecular pump (Figure 1.15) [11]. Gaede used the finding that any gas molecule hitting a wall stays at its location for a while and accommodates to the wall before it leaves the same. If therefore a gas particle hits a fast moving wall, it will adopt the velocity of the wall and is transported in the direction of the motion during its sojourn time. The pumps based on this principle require very high rotor speeds and low clearances of about between the moving wall and the fixed wall. The pump floundered on these requirements, which were too stringent for the technology available at the time. In 1958, however, Becker utilized the principle and invented the turbomolecular pump [12], which eased the clearance problem.

Figure 1.15Gaede's molecular pump of 1912.

In the years 1915 and 1916, Gaede and Langmuir developed the mercury diffusion pump [13,14]. Twelve years later, the oil diffusion pump followed, which was the most widespread pump until the turbomolecular pump was developed.

In addition, vacuum measurement also developed further (Figure 1.16) using other pressure-dependent properties of gases: Sutherland suggested to use the viscosity of gases in 1897. Langmuir put this principle into practice in 1913 using an oscillating quartz fiber. The decrement in amplitude of the oscillations gave a measure of gas pressure. In 1960, J. W. Beams demonstrated that the deceleration in rotational frequency of a magnetically suspended steel ball rotating at about 1 MHz under vacuum could be used as a measure of pressure. Fremerey optimized this device during the 1970s and 1980s. Pirani [15] used the pressure dependence of thermal conductivity and built the first thermal conductivity gauge in 1906. In 1909, von Baeyer showed that a triode vacuum tube could be used as a vacuum gauge. Penning invented the cold cathode gauge in 1937 in which a gas discharge is established by crossed electric and magnetic fields. During the Second World War, mass spectrometers were developed, and they became crucial parts of the weapons industry.

Figure 1.16 Progress in lowest pressures generated and measured in the twentieth century. (Data from Ref. [6].)

After World War II, it was generally believed that diffusion pumps would not be able to generate pressures below Torr although the underlying effect was unknown. All manufacturers' pumping speed curves showed a value of zero at this point. The pressure was measured using triode gauges. During the Physical Electronics Conference in 1947, Nottingham suggested that the impingement of X-ray photons on the collector of the triode causing secondary electrons might be the reason for this lower pressure limit. This was a breakthrough. A competition for a significant improvement of the ion gauge started, which Nottingham's own group did not win, to his regret. Instead, in 1950, Bayard and Alpert [16] succeeded with an idea as simple as ingenious (Figure 13.48).

Since all vacuum gauges except for the McLeod and the Torricellian tube had to be calibrated, and because, at the same time, vacuum industry grew to an important branch (see Chapter 2), independent metrological laboratories were set up in state-owned institutes in the late 1950s. The first were established at the National Physical Laboratory (NPL) in England. The Laboratory for Vacuum Physics (today: Vacuum Metrology) at the Physikalisch-Technische Bundesanstalt1 (PTB) in Germany followed in 1966, and in the 1970s the Vacuum Laboratory at the National Bureau of Standards (NBS; today: NIST) in the United States.

Coming back to the philosophical considerations at the beginning of this chapter, let us make a concluding remark on the nature of vacuum from the point of view of today's physics [17,18]: without any doubt, there are macroscopic areas, for example, small volumes between galaxies, where there is no single molecule (Figure 1.17). For such a volume, the term absolute vacuum was introduced. We know today, however, that even absolute vacuum is not empty (in terms of energy). Otherwise, it would not be in accordance with the laws of nature. A vacuum energy with still unknown nature, which may be related to the cosmological constant introduced by Einstein, permits particles to be generated spontaneously by fluctuating quantum fields for short time intervals, even in absolute vacuum. In this sense, there is no space in the world, which is truly empty.

Figure 1.17 In between galaxies, there are small volumes of a few dm3 without any massive particle (absolute or ideal vacuum). Oldest known galaxies pictured by the Hubble Space Telescope. (Courtesy of NASA.)

Note

1.

German National Metrology Institute.

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