Year 3 BSc Final Year Project Abstracts (PHYS3018) Academic Year 2009/10 ASTRONOMY & SPACE PHYSICS A1 SPECTRAL EVOLUTION DURING HIGH MASS XRAY BINARY OUTBURSTS Dr Tony Bird email ajb@astro.soton.ac.uk Room 4061 Observations made with Xray instruments during outbursts from some massive Xray binary systems show indications of different emission spectra and outburst profiles. These differences may be related to the outburst intensity, the type of outburst or other factors, such as the presence of an accretion disk or mass accretion rate. The aim of this project is to analyse observations of Xray binary systems in outburst to try to quantify any spectral variations in the outburst profiles and relate them to the physical characteristics of the binary systems. The project will make use of archival data from the RXTE, Swift and INTEGRAL telescopes. There may also be an opportunity to compare the Xray behaviour with optical data observations of the same systems. ^ Prof Malcolm Coe email mjc@astro.soton.ac.uk Room 5049 This project will make use of a specialist solar telescope to study phenomena associated with the Sun.
The project will require multiple observations to be carried out throughout the term to build up a history of solar activity. The observational data may be supplemented by data acquired off the internet. ^ Dr Christian Knigge email Christian@astro.soton.ac.uk Room 5029 The School of Physics & Astronomy owns two telescopes sited in two domes on the roof of the Physics Building. For astronomical observations with these telescopes, 3 highsensitivity CCD cameras and a variety of filters are available. The first goal of this project will be to answer key questions about the observing site and our equipment, such as: what is the throughput of the various components (i.e. what are the faintest objects that can be observed with a given telescope/camera combination)? How good or bad is the "seeing" from Southampton? How strong and wavelengthdependent is the atmospheric extinction? How high and stable is the CCD dark current (which adds unavoidable noise to every observation)? How clean and stable are the flat fields (i.e. the sensitivity variations across the field of view)? How broad or narrow are the various filter windows? Some of these questions can be answered with daytime experimental work, but others require night time observations of astronomical targets. Having obtained this calibration data, student will then apply this to a set of astronomical data in order to carry out a highprecision photometric analysis on a topic of their choice (the possibilities here include star clusters, variable stars, galaxies...). Note: This project cannot be done by a single student (for Health & Safety reasons). It is also likely to require some night work. ^ Prof Betty Lanchester email: bsl@phys.soton.ac.uk Room: 4091 The aurora is caused by energetic particles precipitating into the atmosphere and ionising and exciting oxygen and nitrogen molecules and atoms, which emit light of different wavelengths. These emissions can be measured by a variety of optical instruments, including photometers, and spectrographs. Data from such instruments will be used in this project. The instruments are in two locations within the region of auroral occurrence. Ratios of different emissions have been used for many years to estimate the energy of precipitation by association with the height of the emitting regions. The intensity ratio is dependent on height, and therefore such ratios can be used to derive the height of the aurora. The project will investigate the differences in these ratios at different times of the night. The aim of the project is to determine whether the changes in ratios can be associated with different sources, with origins in the Earth’s magnetosphere. The project will require the use of IDL routines, most of which already exist, but some programming will be needed. Programme:
J. W. Chamberlain, Physics of the Aurora and Airglow, International Geophysical Series, Academic press, 1961. Vallance Jones, Aurora, D. Reidel Publishing Company, 1974.
^ Dr Tom Maccarone email: tjm@astro.soton.ac.uk Room: 5061 Students will do a computational investigation of the stability of few body orbits, by computing the gravitational forces on the objects from one another to solve the orbital evolution numerically. Some flexibility will exist in the project, depending on student interests. This project can accomodate more than two students, for this reason. Possible streams include: understanding under what conditions triple and quadruple star systems can exist, understanding the orbital eccentricities in extrasolar planet systems, and understanding what the end products are of close stellar interactions such as those that occur in globular clusters. (Some prior programming experience is required for this project). ^ Prof Ian McHardy email: imh@astro.soton.ac.uk Room: 5011 Almost everything in the universe, including the price of stocks and shares, varies. But how can we quantify and characterise the variability? Is there any deep driving force underlying the variability of the stock market or is it purely a random noise process? In this project the student will apply some of the techniques which we currently apply to the analysis of the Xray variability of stars and galaxies to try and make sense of variations in stock market price (if there is any sense in them). When we observe the variability of some system as a function of time, eg the way in which the light output from a star changes with time, or the way in which share prices vary with time, we produce something called a `time series'. For the specific case of the light from a variable star the time series would be called a `light curve'. One particularly common way of quantifying variability is to calculate, using Fourier transforms, something called the `power spectrum' of the time series. The power spectrum gives us the amount of power in the variability at different frequencies. In other words it turns a function of time into a function of frequency. If the variable star is varying periodically, then we will see a peak in the power spectrum at the characteristic frequency of the variations. In this project, students will write their own computer code to turn time series into power spectra and will apply that code to the analysis both of some astronomical lightcurves, and of share price variations. Depending on how quickly the student progresses, other techniques may be applied to try and make sense of the variations. (BSc Project or, with extension, an MPhys project) ^ Q1 TERAHERTZ SPECTROSCOPY APPLICATIONS IN BIOLOGY AND MEDICINE Dr Vasilis Apostolopoulos, email: v.apostolopoulos@phys.soton.ac.uk Room: 5059 THz time domain spectroscopy has recently emerged as a useful and powerful spectroscopical tool, owing to the fact that it provides a probe of the complex conductivity over a wide frequency range, with subpicosecond time resolution. Due to recent advances in femtosecond lasers and optical materials, the THz radiation band from 0.1 to 10THz is now routinely accessible. Terahertz (THz) spectroscopy is used now as a powerful technique to identify and characterize molecular species. The object of the dissertation is to explain the principle of THz TDs and explore the biological – medical applications such as DNA hybridization detection, protein dynamics, skin and breast cancer detection etc. Finally the recent attempts to integrate THz spectrometers can be also documented. ^ Dr Vasilis Apostolopoulos email: v.apostolopoulos@phys.soton.ac.uk Room: 5059 THz time domain spectroscopy (THzTDS) has recently emerged as a useful and powerful probe of material properties, owing to the fact that it provides a probe of the complex conductivity over a wide frequency range, with subpicosecond time resolution. As such, it has many advantages over more conventional techniques such as resistivity and Hall measurements: it is an alloptical technique (and therefore contactless) and allows the study of nondoped (pristine) samples. The object of the dissertation is to explain the principle of THzTDs and explain the principle behind algorithms used to extract material information. Then explore the applications these technique have in the characterization of semiconducting behavior, liquid crystals, protein and biological function. ^ Prof Peter de Groot, email: pajdeg@phys.soton.ac.uk Room: 5021 Magnetism offers some of the best model systems for the study of manybody Physics. Magnetic materials and devices are also at the heart of many applications: magnetic data storage, microwave and r.f., bulk magnets for electromotors and generators, transformers, etc. Mostly these applications are based on ferromagnetic (magnetically ordered) materials. Recent, new developments include the use of magnetic nanoparticles for medical and biotechnical applications. The aim of this project is to develop and use simple computational, MonteCarlo models to explore ordering in magnetic nanoparticles and the effect of disorder (which is always present in real materials) on magnetic phase transitions. Enthusiasm for computer programming and some knowledge of a programming language – for instance Python or C++ – will be essential. ^ Dr Tim Freegarde email tim.freegarde@soton.ac.uk Room: 5071 According to Maxwell's welltested theories, the resonant frequency of a simple LC circuit depends only upon the component dimensions and the speed of light. By constructing from scratch a range of airspaced capacitors and inductors, measuring the resonant frequencies of their combinations, and carefully accounting for measurement and end effects, this project allows the speed of light to be determined absolutely in a benchtop experiment. This project is suitable for third year undergraduates ^ Dr M. Kaczmarek email mfk@soton.ac.uk Room 5047 Optical and dielectric anisotropies of liquid crystals are important parameters for their application in display technologies and optoelectronics. The aim of this project is to estimate the magnitude of optical anisotropy in different liquid crystals. The first part of the project will be devoted to gaining better understanding and handson experience in alignment of liquid crystals, their response to increased temperature and to electric field. In the second part, cells with different liquid crystals will be tested. Light transmission characteristics in liquid crystal cells will be taken for different values of applied electric field. Data will then be analysed to determine the liquid crystals' effective optical anisotropy. ^ Dr Peter Lanchester email p.c.lanchester @soton.ac.uk Room 3026 A feature of the first year laboratory is the inclusion of a number of three week long miniprojects. All physics students undertake two such projects, one in each semester (normally working in pairs). So far just six projects are offered and there is a need for additional projects, especially in the area of computer control of experiments and automated acquisition of data. The aim of this project will be to devise, test and produce appropriate guidance notes for a new miniproject based on the National Instruments ‘LabView’ range of hardware and software, which is widely used both in research and in industry. Note: this project is especially suitable for students who anticipate a career in laboratory based physics research or teaching. ^ Dr Otto Muskens email om1v08@soton.ac.uk Room 5067 Small particles scatter light. If we put a lot of them together they form a random material in which light bounces many time like in a pinball machine. Examples in everyday life are milk, clouds, and paint. When coherent light from a laser is directed onto such an opaque scattering medium, the light is scrambled but some of its coherence remains. In this project, the student will investigate which coherent aspects of light survive multiple scattering. The student will study phenomena like speckle, coherent backscattering, and diffusive wave spectroscopy. Materials will be taken both from everyday life and from stateoftheart nanophotonics research. ^ Dr David Smith email dcsmith@phys.soton.ac.uk Room 5003 Surface Plasmon Polaritons (SPP) are waves found at the surface between a metal and a dielectric which consist of a combination of an electromagnetic wave in both the metal and the dielectric and a motion of the free electrons in the metal. The involvement of the electrons in the wave means that the wavevector of the SPP parallel to the surface is bigger than the magnitude of the wavevector of light of the same frequency in the dielectric above the interface and so the SPP are trapped at the interface. SPP are already used in a number of technological areas and this is one of the big growth areas in optical physics at the moment. One particular area is in producing sensors capable of detecting the binding between two biomolecules. This project will involve investigating how it is possible to create SPPs using light and using this to measure the dispersion relation of SPPs at the interface between silver, and possibly gold, and air. The project will require the students to deposit a thin film of the metal using thermal evaporation, characterise the film using optical transmission measurements to determine its thickness and then use the film to measure the dispersion relation of the SPPs at the interface. An existing simulation program will then be used to predict the SPP dispersion relation and conclusions drawn about the comparison between theory and experiment. The apparatus to enable all of the measurements already exists and been used to make such measurements. ^ T1 STUDY OF HIGGS BOSON PROPERTIES AT THE INTERNATIONAL LINEAR COLLIDER Dr Sasha Belyaev email a.belyaev@phys.soton.ac.uk Room 5053 We expect that Higgs boson will be discovered at Large Hadron Collider (LHC), however its properties can be only well understood at the ILC where precision measurement of Higgs boson properties can be performed. This is the subject of this project. This study can be effectively performed with CalcHEP package for automatic calculations of elementary particle production and decay processes. The package is so user friendly that it can be used even at High School to learn Elementary Particle Physics. It has builtin 2D and 3D plotter so one can quickly create analysis plots. The outcome of the project is the study of Higgs boson properties at the ILC using CalcHEP. ^ Dr Beatriz de Carlos email b.decarlos@soton.ac.uk Room 5021 Neutrinos are the lightest elementary particles, indeed so light that, until very recently, they were thought to be massless like the photon. However the observation of neutrino oscillations in several experiments can be directly linked to the existence of a mass for them. In this project we propose to review the quantum mechanical calculation of the probability that a neutrino of a certain flavour would be observed, after a certain amount of time, to be of a different flavour (the three possible flavours being electron, muon and tau). This probability can be related to the mass difference between flavours and a certain mixing angle, and the final part of the project would be to relate the theoretical calculation to the data recorded by the different experiments until now. Prerequisites PHYS2003 or, in other words, a basic knowledge of quantum mechanics. Structure The project comprises a first part which is mainly theoretical, reviewing the concepts of eigenstates and eigenvalues of a quantum mechanical system, and applying them to a system of neutrinos. This leads to transition probabilities of the form where an alphatype neutrino is converted into a betatype one. L is the distance travelled and E the energy of any neutrino type (in this approximation their momenta is much larger than their mass). The second part will be devoted to matching the theoretical calculation to the experimental data. Typical plots are ^ Dr P Di Bari email: P.DiBari@soton.ac.uk Room: 5063 The diffusion equation is one of the most relevant (partial) differential equations in physics. Despite its long history with many classical applications ranging in a host of traditional disciplines, the diffusion equation is also of great importance to describe processes involved in hot topics in modern physics. The aim of this project is to study, starting from a well known traditional problem, the spread of the wave packet in quantum mechanics, two very timely applications: the first is the diffusion of cosmic rays in the galactic medium (the so called diffusion lost equation), relevant in recent claims of Dark Matter discovery, while the second is the so called “BlackScholes” model in economics. The project will require both analytical and numerical skills. Starting from a well known equation, the student will be therefore introduced into modern research subjects and above all will be able to appreciate the great versatility of mathematical tools in modelling relevant physical problems. ^ Prof Jonathan Flynn email j.flynn@hep.phys.soton.ac.uk Room 5009 The aim of the project is to use numerical simulations to produce animations of the timedependence of some simple quantum mechanical systems to help improve your intuitive understanding. Examples could include the behaviour of a wave packets in an infinite square well or harmonic oscillator potential, tunnelling through potential barriers and scattering by potential barriers and wells. (The BSc project could be done by more than two students if need be (they can do a common "core" of work and then do different extensions/applications). *** Project requires computing *** T5 THE LHC OLYMPICS ^ The CERN Large Hadron Collider (LHC) will have just switched on by the time you are starting this project. LHC is the highest energy particle collider in the world. Noone knows for sure what it will discover, but whatever it is sure to revolutionize physics. Over the last years, physicists from across the world have been organising a series of data challenges called the LHC Olympics in which new physics signals are simulated at the LHC as a series of data ``black boxes’’. This project will consist of analysing data based on Standard Model processes such as top quark pair production and W boson pair production which provide the background to new physics signals. This project will be very challenging, but may be tackled by anyone who is strong in computing with a strong interest in particle physics. ^ http://www.phys.washington.edu/users/strasslr/LHCO.BBpage.html T6 DETERMINATION OF THE ECCENTRICITY OF THE EARTH’S ORBIT….. FROM SUNRISE/SUNSET TIMES Prof. D.A. Ross email d.ross@hep.phys.soton.ac.uk Room 5017 As the Earth rotates about the sun, the inclination of the Earth's axis of rotation to the sun changes. For this reason points on the Earth at different latitudes observe sunrise and sunset at different times for different times of the year. Using Kepler's laws and some solid geometry, it is possible to predict these times as a function of the eccentricity of the Earth's orbit. By comparing these predictions with actual times (available on the Internet), the eccentricity of the Earth's orbit can be inferred. This is a theoretical project involving some computing. T7 COMPUTATIONAL STUDIES OF QUANTUM MECHANICAL SCATTERING Prof C Sachrajda email cts@hep.phys.soton.ac.uk Room 5001 Most problems in physics cannot be solved analytically and computational techniques have to be applied to obtain numerical solutions. This is true in particular for scattering in quantum mechanics, for which the wave functions of the final state can only be determined for a few very simple potentials. The students will consider a number of examples, determine the appropriate numerical methods with which to tackle the problems, and write and run the code to obtain the solutions. The specific examples will be chosen to match the students’ interest, experience and expertise but a possible thesis might include studies of:
