Course Materials

Lecture 1 - Electrical Power and Grounding

Thursday, Oct 1. Covered basic physical properties of electricity (charge, current, voltage, resistance, capacitance, power); some properties of 'real' power supplies and wires; distribution of power in the US, including 1-phase and 3-phase supplies.

Alex's lecture notes (docx, 164K)
Common symbols for drawing circuits (pdf, 221K)
Principles of Electronic Instrumentation, chapter 1 (pdf, 307K)
Principles of Electronic Instrumentation, chapter 3 (pdf, 287K)
Solutions to selected chapter-end problems

Lecture 2 - Vacuum Pumps

Thursday, Oct 8. Basic principles and operation of vacuum pumps, especially rotary-vane and turbomolecular pumps. Performance specifications, mtainenance and repair.


Lecture notes (pdf, 0.2M)
Lecture slides (pdf, 4.1M)
Creating a vacuum (pdf)
Pump Down Curves (pdf)
Pumpdown curves as diagnostics (pdf)
Pumping speed in the drydown zone (pdf)
Turbo vs Drag pumps (pdf)

Lecture 3 - Vacuum theory and gauges

Thursday, Oct 15. Basic theory of flow at low pressure, viscous vs molecular flow, mean free path, pump-down curves, water adsorption. Types of pressure gauges: manometers, mechanical gauges, heat-loss gauges, ionization gauges.

Alex's lecture notes
Lecture slides
Using the fundamental vacuum relationship Q=SP (pdf)
Theory of thermal conductivity pressure gauges (pdf)

Extra reading:

Lecture 4 - Inlet systems

Thursday, Oct 22. Theory of viscous capillary leaks; duel-inlet sources and changeover valves; continuous-flow (carrier-gas) inlets; open splits and reference gas introduction in continuous flow systems.

Alex’s lecture notes
Halsted and Nier (1950) Gas flow through the mass spectrometer viscous leak.
McKinney et al (1950) Improvements in mass spectrometers for the measurement of small differences in isotope abundance ratios.
Shackleton (1965) The high-precision isotopic analysis of oxygen and carbon in carbon dioxide.
Hayes (1977) High precision stable isotope ratios from microgram samples.

Lecture 5 - Ionization Sources

Thursday, October 29. Types and characteristics of ionization sources. Physical characteristics and optimization of Nier-type EI source. Electrostatic lenses, focusing, collimation of ion beams.

Alex’s lecture notes
Lecture 5 slides
Nier (1947) A mass spectrometer for isotope and gas analysis.

Lecture 6 - Mass Analyzers

Thursday, November 5. Types and characteristics of mass analyzers and spectrometers. Force balance model for magnetic sector instruments; magnetic and electric sectors, focusing, dispersion, resolution, abundance sensitivity.

Alex’s lecture notes
Lecture 6 slides
Laeter and Kurz (2006) Alfred Nier and the sector field mass spectrometer.

Lecture 7 - Detectors

Thursday, November 12. Faraday cups, feedback electrometer circuits, secondary ion counters.

Alex’s lecture notes
(no slides this week)

Hayes and Schoeller (1977) High precision pulse counting: Limitations and optimal conditions.
Hayes, Matthews and Schoeller (1978) Effective dead time of pulse-counting detector systems.

Lecture 8 - Data Systems and Noise

Thursday, November 19. Counting statistical limits to precision; analog-to-digital conversion; data communications

Alex’s lecture notes
(no slides this week)

Peterson and Hayes (1978) Signal-to-noise ratios in mass spectroscopic ion-current-measurement systems.
Santrock, Studley and Hayes (1985) Isotopic analyses based on the mass spectrum of carbon dioxide.
Ricci, Merrit, Freeman and Hayes (1994) Acquisition and processing of data for isotope-ratio-monitoring mass spectrometry.
John and Adkins (2010) Analysis of dissolved iron isotopes in seawater.

Cheat Sheet for converting readout voltage, ion current, count rate, and limiting precision.

© Alex Sessions 2011