When cooled below a certain critical temperature, some materials become perfect conductors. This phenomena is known as superconductivity and was first successfully described by Bardeen, Cooper and Schrieffer in 1957 (now known as BCS theory). Electrons form cooper pairs and undergo phonon interactions with the metallic lattice.

The slides outline superconductivity and the BCS theory.

Keynote slides


Metals, Crystals and Bragg Diffraction

These slides give an overview of metallic structure and conduction. The concept of a crystal lattice is also introduced, in addition to the method of x-ray diffraction (pioneered by William and William Bragg) which was used to determine the crystal structure of metals.

Keynote slides

Thermionic Devices and Computing

Before the widespread use of semiconductors, it was possible to compute data electronically using thermionic devices such as valves. These had a number of of functional inadequacies and were eventually superseded by the more compact and reliable solid state alternatives (transistors, diodes and integrated circuits).

The slides outline this progression, including the transition from germanium to silicon.

Keynote slides

Semiconductors and doping

These slides provide an introduction to semiconductors, beginning with energy levels and the formation of energy bands in solid materials (conduction band, valance band). Conductors, insulators and semiconductors are compared in terms of their band structure. The effect of dopant atoms on the electrical properties of semiconductors is also mentioned (p-type, n-type).

Keynote slides

Radioisotope and PET imaging

The rapidly expanding field of nuclear medicine involves the insertion of radioactive substances into the patient. These may be attached to various pharmaceuticals, and the location of the isotope is recorded using gamma detectors. PET scans utilise isotopes which undergo beta + decay. The antiparallel gamma photons resulting from the electron-positron annihilation is recorded by the detector.

Theses slides outline the use of radioisotopes in both conventional and PET nuclear imaging.

Keynote slides

X-ray and Endoscopy

The electromagnetic spectrum is very useful for diagnostic imaging of the human body. These slides outline the production and implementation of X-rays in imaging, including soft and hard X-rays as well as CAT scans. The practise of using visible light to image the body through the process of endoscopy is also introduced (including total internal reflection, coherent and incoherent fibre optic bundles).

Keynote slides