PH31610 - THERMAL AND CRYOGENIC PHYSICS

Module Identifier	PH31610
Module Title	THERMAL AND CRYOGENIC PHYSICS
Academic Year	2001/2002
Co-ordinator	Dr Geraint Thomas
Semester	Intended for use in future years
Next year offered	N/A
Next semester offered	N/A
Other staff	Professor Geraint Vaughan, Dr Eleri Pryse
Pre-Requisite	PH21510 , PH23010 , PH26010 , PH27010
Course delivery	Lecture	22 lectures
Assessment	Course work		20%
	Exam	2 Hours End of semester examinations	80%

Module description

This module builds on the earlier thermodynamic module PH21510. The aim of the module is to introduce further thermodynamic variables, functions and techniques and apply them to practical systems. An important element will be to demonstrate the application and usefulness of thermodynamics to the study of systems other than gaseous systems, for example to liquid-gas phase changes and also to magnetic systems. The use of thermodynamics for the generation of low temperatures will also be discussed in some detail. In addition the special properties of some materials at low cryogenic temperatures will be discussed, e.g. superconductivity and superfluidity.

Learning outcomes

After taking this module students hould be able to:

understand phase change and the Clausius-Clapeyron equation.
understand Joule and Joule-Kelvin expansion and their practical application to refrigeration.
understand low temperature phenomena from a macroscopic and microscopic point of view.
be aware of methods for generating and measuring low temperatures.
understand, in qualitative terms the origins and principal properties of superconductors and superfluids.

Outline syllabus

Thermodynamic potentials.
Maxwell relations, thermodynamic variables.
First order phase changes: Gibbs function and Clausius-Clapeyron equation.
Second and higher order phase changes.
Ehrenfests classification, examples of different order.
Joule and Joule-Kelvin expansion and application to refrigeration.
Pomerantchuck cooling.
Adiabatic demagnetisation: attainment of very low temperatures.
Laser cooling of atoms.
Measurement of low temperatures.
Superconductivity.
Superfluidity: properties of liquid helium.
Third Law of thermodynamics: entropy near absolute zero.
Negative temperatures and population inversion.

Reading Lists

Books
** Recommended Text
A. Kent. Experimental Low-Temperature Physics. MacMillan ISBN 0333519507
C. Finn. Thermal Physics. Chapman Hall ISBN 0412495406
** Supplementary Text
M. Sprackling. Thermal Physics. MacMillan Physical Sciences ISBN 0883189194