Department of Physics, Unit Catalogue 2007/08 |
PH20029 Thermal physics |
| Credits: 6 |
| Level: Intermediate |
| Semester: 1 |
| Assessment: EX 100% |
| Requisites: |
| Before taking this unit you must (take PH10002 or take PH10052) and take PH10007 and take PH10008 |
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Aims: The aims of this unit are to develop a sound understanding of the concepts of classical thermodynamics and their application to physical processes and to introduce the concepts of statistical mechanics, showing how one builds from an elementary treatment based on a description of microstates to a discussion of Fermi and Bose systems.
Learning Outcomes: After taking this unit the student should be able to: * define and understand thermodynamic terms such as temperature, equilibrium, function of state, reversibility; * understand and apply the 1st and 2nd laws; * define entropy and the common thermodynamic potentials and understand their importance to phase changes; * appreciate the need for a microscopic approach to thermal physics and demonstrate an understanding of the microstate formalism; * derive the appropriate thermodynamic potentials from the partition function of simple models; * calculate averages, heat capacities and other thermodynamic variables for simple models; * describe the Fermi-Dirac, Bose-Einstein, Boltzmann and Planck distribution functions and apply them to simple models. Skills: Numeracy T/F A, Problem Solving T/F A. Content: Overview (1 hour): Macroscopic and microscopic approaches to thermal physics. Classical thermodynamics (8 hours): Basic thermodynamic concepts. The second law of thermodynamics. Entropy. Analytical thermodynamics; application to phase changes. Statistical mechanics (8 hours): Microstates and macrostates of an isolated system, density of states, partition function. Principle of equal a priori probabilities; entropy, equilibrium and the second law. Systems in thermal contact with heat reservoir; the Boltzmann distribution. Canonical ensemble. Free energy minimisation. Systems of weakly interacting constituents (2 hours): Ideal gas and indistinguishability. Equipartition theorem. Maxwellian gas. Quantum gases (2 hours): Indistinguishability. Fermions and bosons. Low density limit. Systems with variable particle number (1 hour): Grand canonical distribution; chemical potential. |