This course investigates further the topics of magnetism and electromagnetic waves.
Diamagnets, Paramagnets, Ferromagnetics, Magnetisation M, Magnetisation current, Magnetic intensity H, Magnetic permeability, Magnetic susceptibility, Magnetic circuits, Reluctance, Hysteresis, Permanent magnets, Boundary conditions for B and H.
Displacement current, fourth Maxwell equation, review of vector analysis, Electromagnetic Waves, Speed, Refractive index, Attenuation, Skin depth, Uniform Plane waves, Linear Polarisation, Energy density and Power of Waves, Waves at Boundaries - reflection & refraction.
Fresnel's equations, Brewster angle, Total Internal reflection.
Radiation Detection and Measurement:
· Types of Radiation: general characteristics of alphas, betas, gamma- and X-rays, and neutrons. Typical radioactive sources and methods of production. Energy units (keV, MeV) and Q-values.
· Interactions of Radiation with Matter: Definitions of suitable units: activity, exposure, absorbed dose, dose equivalent. Interactions with matter of heavy charged particles, electrons, photons and neutrons. Selection of suitable shielding materials.
· Radiation Detector Properties and Measurements: covering the basic mechanisms of charge generation and transport in detectors, pulse processing using typical readout electronics, energy resolution and contributions to detector noise.
· An overview of types of Radiation Detector:
i. Gas Detectors: Ionisation processes, drift velocity and mobility. Ionisation chambers, Avalanche.Proportional counters and Geiger-Muller Tubes.
ii. Scintillation Detectors: principles of the Photo-Multiplier tube, Organic scintillators (liquid, plastic) and Inorganic scintillators (NaI(Tl), BGO).
- Semiconductor Detectors: Introduction to semiconductor properties: the band gap, reverse-biased junction and depletion regions. X-ray spectroscopy with planar Si detectors with Si(Li) and Ge detectors, Alpha particle spectroscopy with planar Si detectors. New high-Z semiconductors (GaAs, CdZnTe) for X-ray detection.
Exploring the Solar System:
Overview of the Solar System: Familiarity with the basic properties of the major planets orbiting the Sun and with the minor bodies of the Solar System. Properties of planetary orbits. Sidereal and Synodic Periods. Escape Velocity. Spin-orbit coupling (resonance). Properties of Planets: Planetary surfaces and interiors; cratering record – significance for dating planetary surfaces; evidence for geological activity; differentiation of material; magnetic fields. Atmospheres: composition, Maxwellian distribution of molecular, retention. Planetary temperatures. Moons and Rings. Differential gravitational forces (tides).
Formation of the Solar System: Solar Nebula Theory. Star formation; T-Tauri phase. Circumstellar discs. Distribution of angular momentum. Evaporation and condensation of dust. The “ice-line”. Formation of planetesimals and planets. The Oort cloud and Kuiper belt.
Exploration of the Moon: Early Pioneer and Ranger missions; Lunar Orbiter – photographic system, discovery of “mascons” – suggested mechanism for their creation; the Surveyor programme – soil analysis. Lunik and Luna programmes: use of NaI γ-ray spectrometer. Apollo missions – age and composition of the surface – maria and highlands.
Exploration of the Terrestrial Planets (Mercury, Venus, Mars): Viewing geometry from Earth: - interior and superior planets, conjunctions, Mercury: Mariner results – temperatures, density, magnetic field, H/He atmosphere, orbital resonance. Cratered nature of the surface – implications for age; similarities and differences with respect to the Moon. Caloris basin. Venus: Venera results – atmospheric composition, temperature and pressure. Pioneer Venus and Magellan radar images; Interpretation of Venus’ surface (young) – suggested mechanism for re-surfacing; Nature of impact craters, evidence for volcanism. Mars: Mariner, Viking, and rover results; volcanoes, ice-caps, evidence for running water.
Exploration of the Jovian Planets (Jupiter, Saturn, Uranus, Neptune): Voyager and Galileo mission results. Jupiter: atmospheric composition, belts and zones, the Great Red Spot; Radiation belt; rings. Galilean moons: Io, Europa,Ganymede, Callisto. Saturn: atmosphere, ring structure, composition. Titan (atmosphere). Uranus, Neptune and Pluto. Current missions to the outer planets: New Horizons.
You will perform a selection of five general physics/satellite technology experiments of two sessions each. You will produce 10 lab diary entries, a full report on one experiment, and make an oral presentation on one experiment. You will receive detailed marking and feedback on how to improve the usefulness of these, to yourself and others. Typical experiments include: Optical fibres, Vibration interferometry, Chaos, Chromatic resolving power of a spectrometer, Laser speckle, optical image processing, supernova burst decay, etc.