Vacuum Techniques

Lecturer: John Robins

"The vacuum environment plays a basic and indispensable role in present day technology and is used by a wide variety of scientists, ... technologists and engineers who work in research, development and industrial production."

This course module will cover the fundamentals of Vacuum Technology. It is based on a text "Basic Vacuum Technology" by Chambers, Fitch and Halliday, which arose out of two-day training courses given by them on behalf of The Institute of Physics to universities and industrial and research establishments. The book has been developed to be suitable for engineers, technicians and postgraduates who need to acquire expertise in vacuum techniques. Two significant differences between my course and the book will be that the present course will concentrate only on the high vacuum and ultrahigh vacuum regions, and the pumps and gauges will be described in greater detail.

Text Book

"Basic Vacuum Technology" by A Chambers, RK Fitch and BS Halliday (Adam Hilger) 1989.

Lectures:

2 per week for 3 weeks.

Tutorials:

1 per week for 3 weeks.

Laboratory:

There is no laboratory work included in this course module but the 3rd Year Teaching Laboratory experiment on Vacuum Techniques may be used for demonstration purposes.

Credit:

This course module (6 lectures) constitutes one half (1/2) of the requirements of one of the optional Honours Courses offered in the Department of Physics. Please consult Dr. Paul Abbott, Honours Course Coordinator, for official course credit details.

Assessment:

The form of the assessment will be discussed during lectures.

Aim:

To present sufficient detail of the fundamental factors involved in the basic components of vacuum technology (namely: gas dynamics, pumps, gauges, system design, system processing and leak detection) that a knowledgeable approach can be made to future design, operation, maintenance and repair of vacuum equipment.

Objectives:

On successful completion of this course, the student should be able to:

• recognise the factors influencing the creation or maintenance of low pressure environments within vacuum systems,
• choose components for a vacuum system that will be compatible with the pressures required,
• choose components for a vacuum system that will be compatible with the work to be carried out within the vacuum environment,
• estimate, with the aid of component specifications, the pumping speeds, pumpdown times, and ultimate pressures of relatively standard vacuum systems,
• read with informed understanding, the descriptions of vacuum systems reported in scientific and technical literature,
• appreciate the significance of reports on future developments in vacuum technology.

Note: This aim and the objectives will be open to discussion and possible modification at the first lecture.

Course Content

Lecture 1:

Introduction to Course Module. Introduction to Vacuum Technology. Pressure units Low pressure regimes and characteristics. Gas dynamics, flow, conductance.

Lecture 2:

Throughput, pumping equations Gas transfer pumps (Rotary and Diffusion). Pumping combinations, pumping rates. A basic pumping system.

Lecture 3:

Gas entrapment pumps. Surface processes and outgassing. [Discussion of Course Assessment]

Lecture 4:

Total pressure measurement. Partial pressure measurement.

Lecture 5:

Vacuum components, valves, etc. Vacuum materials. Cleaning and system processing.

Lecture 6:

Leak detection. Typical systems. Recap of course.

Tutorial 1

Scientific papers. Discussion of their structure.

Tutorial 2

Laboratory demonstration of a Vacuum System. Pumps, cold trap, valves and gauges (3rd Year Lab Expt. on Vacuum Techniques).

Tutorial 3

Scientific talks. Discussion of content of text of a talk.