## PH20029: Thermal physics

[Page last updated: 05 August 2021]

Owning Department/School: Department of Physics
Credits: 6 [equivalent to 12 CATS credits]
Notional Study Hours: 120
Level: Intermediate (FHEQ level 5)
Period:
Semester 1
Assessment Summary: EX 100%
Assessment Detail:
• Composite Examination (EX 100%)
Supplementary Assessment:
Like-for-like reassessment (where allowed by programme regulations)
Requisites: Before or while taking this module you must ( take PH10002 OR take PH10052 ) AND ( take PH10007 OR take MA10230 )
Description: 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:
Classical thermodynamics (9 hours): Basic thermodynamic concepts. The zeroth, first and second law of thermodynamics. Heat engines, thermodynamic potentials, Maxwell relations, entropy. Phase changes.
Introduction to statistical mechanics (4 hours): Microstates. Energy degeneracy. Multiparticle systems. Indistinguishability. Ensemble average. Statistical ensembles. Interacting systems. Temperature. Entropy. Chemical potential. Thermodynamic identity. Postulates and laws of thermodynamics.
Boltzmann distribution and ideal gas (3 hours): Partition function. Boltzmann distribution. Partition function for many particles. Equipartition theorem. Density of states. Particle in a box. Maxwell-Boltzmann distribution. Velocities of particles in a gas. Ideal monoatomic gas.
Fermi and Bose gases (6 hours): Grand-canonical distribution. Fermi gases. Fermi-Dirac distribution. Classical and Quantum statistics. Fermi energy. Fermion gas law. Bose Einstein distribution. Bose-Einstein condensation. Bose gases. Boson gas law. Experiments on atom cooling and Bose condensation. Photon gas. Phonon gas. Heat capacity of an insulating solid.

Programme availability:

#### PH20029 is Compulsory on the following programmes:

Department of Physics
• USPH-AFB01 : BSc(Hons) Physics (Year 2)
• USPH-AAB02 : BSc(Hons) Physics with Study year abroad (Year 2)
• USPH-AKB02 : BSc(Hons) Physics with Year long work placement (Year 2)
• USPH-AFB10 : BSc(Hons) Physics with Astrophysics (Year 2)
• USPH-AAB10 : BSc(Hons) Physics with Astrophysics with Study year abroad (Year 2)
• USPH-AKB10 : BSc(Hons) Physics with Astrophysics with Year long work placement (Year 2)
• USPH-AFM02 : MPhys(Hons) Physics (Year 2)
• USPH-AFM04 : MPhys(Hons) Physics with Research placement (Year 2)
• USPH-AAM03 : MPhys(Hons) Physics with Study year abroad (Year 2)
• USPH-AAM12 : MPhys(Hons) Physics with Study year abroad (Year 2)
• USPH-AKM03 : MPhys(Hons) Physics with Professional Placement (Year 2)
• USPH-AKM04 : MPhys(Hons) Physics with Professional and Research Placements (Year 2)
• USPH-AFM10 : MPhys(Hons) Physics with Astrophysics (Year 2)
• USPH-AFM11 : MPhys(Hons) Physics with Astrophysics with Research placement (Year 2)
• USPH-AAM10 : MPhys(Hons) Physics with Astrophysics with Study year abroad (Year 2)
• USPH-AAM14 : MPhys(Hons) Physics with Astrophysics with Study year abroad (Year 2)
• USPH-AKM10 : MPhys(Hons) Physics with Astrophysics with Professional Placement (Year 2)
• USPH-AKM11 : MPhys(Hons) Physics with Astrophysics with Professional and Research Placements (Year 2)
• USPH-AAM15 : MPhys(Hons) Physics with Astrophysics with Study year abroad and Research Placement (Year 2)
• USPH-AAM13 : MPhys(Hons) Physics with Study year abroad and Research Placement (Year 2)

#### PH20029 is Optional on the following programmes:

Department of Physics
• USXX-AFB03 : BSc(Hons) Mathematics and Physics (Year 2)
• USXX-AAB04 : BSc(Hons) Mathematics and Physics with Study year abroad (Year 2)
• USXX-AKB04 : BSc(Hons) Mathematics and Physics with Year long work placement (Year 2)
• USXX-AFM01 : MSci(Hons) Mathematics and Physics (Year 2)
• USXX-AAM01 : MSci(Hons) Mathematics and Physics with Study year abroad (Year 2)
• USXX-AKM01 : MSci(Hons) Mathematics and Physics with Year long work placement (Year 2)

 Notes: This unit catalogue is applicable for the 2021/22 academic year only. Students continuing their studies into 2022/23 and beyond should not assume that this unit will be available in future years in the format displayed here for 2021/22. Programmes and units are subject to change in accordance with normal University procedures. Availability of units will be subject to constraints such as staff availability, minimum and maximum group sizes, and timetabling factors as well as a student's ability to meet any pre-requisite rules. Find out more about these and other important University terms and conditions here.