《PRESSURE MEASUREMENT IN VACUUM SYSTEMS》

1Mechanical Manometers1

1.1.Liquid manometers1

1.2.The McLeod gauge3

1.3.The diaphragm manometer21

1.4.Viscosity gauges35

2Thermal Conductivity Gauges40

2.1.Basic principles40

2.2.Measurement of thermal conductivity43

2.3.Sensitivity46

2.4.End losses47

2.5.Accommodation coefficient47

2.6.Alternative methods of bridge control50

2.7.Useful range of the constant-voltage bridge50

2.8.The lower limit to the useful pressure range51

2.9.The importance of bridge-voltage and temperature fluctuations at high pressure56

2.10.Compensation for temperature and voltage fluctuations57

2.11.Physical change in the gauge wire(ageing effects)59

2.12.The construction and operation of a gauge for routine measurements60

2.13.The thermocouple gauge66

Appendix 2.1.Effect of heat conduction along the wire70

Appendix 2.2.Effect of ambient temperature on the gauge reading74

3Ionization Gauges77

3.1.Positive ion production in a gas77

3.2.The principle of the thermionic cathode gauge79

3.3.The relative sensitivity for different gases81

3.4.The calculation of gauge sensitivity84

3.5.Gauge construction88

3.6.The measurement of very low pressures—the Bayard-Alpert gauge92

3.7.The maximum useful operating pressure100

3.8.The cathode102

3.9.Electrical control circuits104

3.10.Valve amplifiers for measurement of positive ion current112

3.11.The cold-cathode ionization gauge—the Penning gauge113

3.12.Hot cathode ionization gauges with crossed electric and magnetic fields120

3.13.Gas clean-up in the hot-cathode ionization gauge122

3.14.Gas clean-up in the Penning gauge128

3.15.Operation of the hot-cathode ionization gauge129

3.16.Operation of the cold-cathode ionization gauge132

3.17.Gauges with radioactive sources.132

4The Knudsen Radiometer Gauge135

4.1.Theoretical considerations135

4.2.Experimental verification of theory140

4.3.Practical developments of the Knudsen design144

4.4.The pressure range with a linear scale152

4.5.The gauge time constant153

4.6.The radiometer force in the high-pressure range154

4.7.Practical application of this gauge.158

5Surface Reaction Techniques159

5.1.Surface contamination159

5.2.Observations of work-function changes160

5.3.Flash filament techniques164

5.4.Field-emission microscope166

6 Gauge Calibration168

6.1.Static methods168

6.2.Dynamic methods170

6.3.Calibration standards176

7 Analysis of the Residual Gases in the Vacuum System177

7.1.Introduction177

7.2.The magnetic deflection mass spectrometer178

7.3.The trochoidal(or cycloidal)mass spectrometer186

7.4.The omegatron188

7.5.Linear resonance mass spectrometers194

7.6.Time-of-flight mass spectrometers196

7.7.A comparison of different analysers198

References202

Subject Index213

Author Index218