Project Descriptions 2017

If no project description is available here, please contact the supervisor directly.

Cooling the MICE Target

Dr. C N Booth - D24

The target for the Muon Ionisation Cooling Experiment, MICE, consists of a small piece of titanium which is driven into the halo of the proton beam of the ISIS accelerator in order to generate (eventually) muons. The target is mounted at the bottom of a shaft, which in turn is connected to a set of magnets positioned in a series of fixed coils. When the coils are pulsed, the target is driven in and out of the beam as required. In addition to the small number of protons generating useful particles in the target, a large number simply pass through the target depositing energy. This energy results in significant heating of the target. Conduction of heat up the shaft will heat up the magnets and may raise them to their Curie temperature, causing failure of the device.

The project requires the construction of a computer model of the thermal properties of the target. Since it is mounted inside a vacuum, only conduction and radiation need be included. Different geometries and materials may be considered, in order to produce a target which will be able to survive the thermal environment.

This project requires a reasonable degree of proficiency in some programming language (Python, C, C++, Fortran, ...). Although there will be the opportunity to consider the interactions of protons with the target, this is not really a particle physics project. Only a knowledge of basic thermal physics is required.

The High-Energy Cosmic Ray Cut-Off

Dr. C N Booth - D24

The origin and composition of high-energy cosmic rays is still somewhat of a mystery, with both galactic and extra-galactic sources being proposed. There are, however, fundamental limits to the distance that the very highest energy cosmic rays should be able to travel. This project uses basic relativity and particle physics to investigate this limit.

High-energy gamma rays will interact with protons, exciting them into unstable states which rapidly decay. In the rest frame of a high energy cosmic ray (assumed here to be a proton), the photons forming the cosmic microwave background appear as having very high energy. A first calculation will be to determine the energy of a proton which can interact with a microwave photon characteristic of the 2.7 K radiation to produce an excited state. Using a formula for the energy dependence of the cross section (in the centre of mass or proton frames), the variation in cross section with cosmic ray energy will be evaluated. More sophisticated treatment will involve considering the black-body spectrum of microwave photons and their angular distribution. Finally, incorporating the number density of the photons will enable the mean free path of high-energy cosmic rays propagating through the universe to be determined.

This project is a modelling and computer simulation exercise. Early parts of the analysis could be performed with simple calculations and computer spreadsheets, but the full evaluation will require programming skills.

The Neutrino Factory and Neutrino Oscillations

Dr. C N Booth - D24

In the Standard Model of Particle Physics, the three types of neutrino are massless particles, and each carries its own specific lepton number which is absolutely conserved. Recent evidence, however, indicates that the neutrinos have very small but finite masses, and that the different types may "mix", allowing for example an electron neutrino produced in the sun to transform into a muon neutrino by the time it reaches the earth.

In order to study such mixing, which can lead to oscillations between neutrino types, it has been proposed that a neutrino factory should be built. This would use the decays of relativistic muons to generate beams of neutrinos, which would then be detected in apparatus hundreds of kilometres away.

This project involves the modelling of muon decay in order to determine the flux of the various neutrino species at a distant site. By considering the cross sections for neutrino interactions in matter, the number of detectable interactions will be determined. Then if neutrino mass and mixing are added to the model, the size of the signal for neutrino oscillation can also be determined.

An initial study should be done with a spreadsheet package such as Excel. More detailed results will more easily be obtained from an analytic program (written for example in C or Python) or a Monte Carlo simulation of the physics involved. Students who make good progress should be able to extend their calculation to incorporate polarisation of the initial muons and different mechanisms for neutrino oscillation. Neutrinos arising from pion decay could also be considered.

This project is suitable for students with ability in a scientific programming language. There is no laboratory work involved.

Neutrino Interaction Projects

Dr. S Cartwright (D22) & P Stowell (D38)

(Note: only one of these topics will be allocated. Please indicate your choice on the form.)

Modelling CC Inclusive Data for Neutrino Interactions

Computing, Data Analysis
A wealth of Charged Current neutrino cross-section data exists for both free nucleon and heavy nuclear targets. Students would be required to use Monte-Carlo neutrino interaction simulation software to compare theoretical scattering predictions to subsets of this data, and with extra time evaluate how the interplay of changing the different interactions modes can help improve the data-simulation agreement.

Improving Sensitivity to Strange Nucleon Content in NC/CC Neutrino Ratios

Computing, Theory
Neutral current (NC) neutrino interactions are sensitive to changes in the strange quark contribution to the nucleon spin. Limits have previously been set with NC data, but large uncertainties in the measurements placed only weak limits on this value. Students would be required to simulate how changes in Delta_s can affect the measured NC cross-section in a detector, and with extra time try to identify regions of the phase-space that could be used to place tighter constraints on the strange nucleon content.

Looking for Sterile Neutrinos in Cross-Section Experiments

Computing, Data Analysis
There exists a long standing disagreement between a number of neutrino experiments in their total measured charged-current neutrino interaction cross-section. With multiple experiments built with slightly different designs and energy ranges, it is difficult to disentangle whether disagreements arise from detector differences or problems with theoretical models. Students would be required to fit sterile neutrino signals to data from multiple short baseline neutrino experiments, and with extra time try to find a single mixing hypothesis that could explain a larger range of the datasets at once.

Comparing NuWro/Neut/GENIE Event Generators in Low Energy Interactions

Computing, Theory
Low energy neutrino interactions in the range 0.1-1 GeV are a considerable problem for neutrino oscillation experiments as they occur in a region where the nuclear medium is difficult to model accurately. Students would be required to compare the kinematic predictions from different Monte-Carlo event generators under different assumptions of the nuclear model, and with extra time try to identify generator differences that might be observable when taking detector thresholds into account.

Development of Demonstrations for Year 2 Electromagnetism Lectures

Prof J W Cockburn - E15

No abstract provided.

Physics of Stringed Musical Instruments

Prof J W Cockburn - E15

In May 2006, a violin known as "The Hammer", made by Antonio Stradivari in 1707 was auctioned by Christie's in New York for 3.45 million dollars, making it the most expensive musical instrument in history. Stradivari's violins, as well as those of other 17th and 18th makers from northern Italy, are highly prized for their tone, projection and aesthetic beauty. However, identification of the "x-factor" that sets these instruments apart from much cheaper (and in some cases physically indistinguishable) instruments by modern makers has eluded scientists for over two hundred years. In this project, the aim will be to learn how violins work, set up experimental systems to measure and characterise the physical response of a violin to external stimuli (based on a precision miniature piezoelectric transducer system recently obtained specifically for this project) and how the response can be modified by design changes. In principle, we can study any stringed instruments (guitars etc) but bowed instruments like the violin are particularly interesting due to their greater complexity and number of "tweakable" components (bridge, soundpost, bassbar etc).

Optical Spectroscopy of Semiconductors

Prof. J.W. Cockburn - E15

Semiconductor optoelectronics has provided the foundations for many of the most important technological advances in recent years. Semiconductor physicists now almost routinely design and develop structures by quantum mechanical engineering of electron wavefunctions in so-called low dimensional structures, advanced multilayer structures where electrons and holes are selectively confined on length scales of a few nanometres. In addition to being of technological significance for the development of new devices (eg lasers and detectors), such structures also allow us to study new regimes of fundamental solid state physics, and contribute to emerging areas such as quantum computing. Optical spectroscopy is perhaps the most important tool for the study of semiconductor physics and devices. This project will begin with a short literature survey of the topic, before moving on to the development of a compact, computer based spectroscopy system for the study of semiconductor materials and low dimensional structures.

Seeing the Invisible World of Particle Radiation

Dr I Dawson (F43) & Prof D Costanzo (D27)

To design a schools outreach presentation demonstrating the "Invisible World of Particle Radiation", using a digital particle camera based on CERN detector technology and recently acquired by the Particle Physics group.

The camera takes nice pictures of alphas, gammas and betas, and even cosmic muons! One of the goals of the project will be to find an effective way of communicating to a general audience this particle world, as well as its connection to the Large Hadron Collider at CERN.

Atomic Spectroscopy

Prof. M A Fox - E14

The aim of the project is to make spectroscopic measurements of the emission lines from a discharge source such as an atomic hydrogen lamp. It will involve setting up and calibrating a spectrometer to make the measurements and analysing the data to determine a value of the Rydberg constant. The spectrum for hydrogen may then be compared with that for sodium in order to obtain values for the quantum defects in sodium.

Shot Noise

Prof. M A Fox - E14

Most photodetectors operate by the photoelectric effect, in which photolectrons are generated following absorption of photons in the sensitive area of the detector. This implies that there is a one-to-one correlation between the photocurrent from the detector and the photon stream of the light beam. One manifestation of the correlation is the presence of shot noise in the photocurrent. This shot noise sets a fundamental quantum limit to the signal to noise ratio that can be obtained in all optical measurements, and is therefore of great importance in optical science. The aim of the project will be to understand the importance of shot noise in optical detection and to build a circuit to measure the shot noise in the photocurrent generated by absorption of light.

Measuring Anisotropic Mechanical Properties of the Bacterial Cell Wall using Atomic Force Microscopy

Prof. J Hobbs - F07

Bacteria have a stiff cell wall that maintains their shape and prevents them from exploding due to osmotic pressure. This cell wall is made of a complex polymer that is found in bacteria but not in animals, and is therefore the target for many antibiotics including penicillin. A knowledge of the physical properties of the cell wall is important if we are to gain an understanding of the physics of these relatively simple living systems, but also has potential for application in the development of new strategies for killing bacteria. In this project the atomic force microscope (AFM) will be used to mechanically probe the cell wall of bacteria, using the sharp AFM tip to deform the wall material in a controlled manner so as to be able to probe whether the wall has different mechanical behaviour in different directions (i.e. anisotropic mechanical properties). The project will involve learning how to use the AFM, application to a biological sample, and analysis of the resultant data using physics models.

Writing at the Nanoscale with Atomic Force Microscopy

Prof. J Hobbs - F07

Atomic force microscopy allows matter to be imaged and manipulated at the nanometre scale. The way in which it works is remarkably simples, taking a sharp probe and dragging it over the surface to 'feel' the structure, and yet it is capable of obtaining images with molecular and even atomic resolution. In this project the Department's new atomic force microscope (AFM) will be used, initially for imaging purposes, but then to explore its capabilities for nanoscale writing with the tip on a range of materials.

Watching Polymers Crystallise with the Atomic Force Microscope

Prof. J Hobbs - F07

Polymers are ubiquitous in modern life, and thin polymer coatings are used in applications from the high tech. to the mundane. However, there are still large areas of polymer physics that are poorly understood, one particularly important example being what controls the morphology of polymers during the process of crystallization. At length scales close to the molecular size (i.e. nanometres) there is remarkably scarce information about the process of crystallization and the kinetics of growth. The aim of this project is to use the atomic force microscope (AFM) to follow crystal growth in situ with nanometre resolution. The project will involve learning how to use the AFM and then using it to image a biodegradable thermoplastic during growth with the aim of exploring the resolution that it is possible to obtain.

Foundations of Quantum Mechanics

Dr P Kok - E12a

Quantum mechanics is a very counterintuitive theory, where particles behave as waves and cats can apparently be alive and dead at the same time. In this project you will study what we can and cannot say about the reality of quantum systems, and how we should interpret the wave function.

This project has a heavy mathematical component.

Measurements at the Heisenberg Limit

Dr P Kok - E12a

Precision measurements are the beating heart of physics. Every time we invented a way to measure something more precisely, new physical phenomena were found. When we repeat measurements of a quantity N times, the error in the measurement is given by 1/√N. However, when we use quantum entanglement, we can improve on this precision. In this project you will discover how.

Laser Optical Beams carrying Non-Zero Orbital Angular Momentum

Dr D Krizhanovskii - E16

Quantised orbital angular momentum (OAM) is associated with topological singularities occurring in many physical systems in optics, condensed matter, cosmology and fundamental particles, characterized by a phase winding of an integer multiple of 2π around a core. Structured light with OAM has been studied for a broad range of applications including quantum information, topological photonics and optical forces. The aim of this project will be to learn how to manipulate laser optical beams using a spatial light modulator or specially designed structured optical elements. The student will develop a technique allowing to induce both amplitude and phase modulation on light and to create twisted optical beams with non-zero OAM. Furthermore, interferometric techniques will be applied to measure spatial phase variations and to characterise such laser optical vortices.

Spectroscopy of Exciton Polaritons

Dr D Krizhanovskii (E16) & M Sich

There is a strong world interest in the study of hybrid light-matter particles in semiconductor microcavities and waveguides, where strong interactions between the photonic mode and exciton results in the formation of polariton quasiparticles. The exciton component leads to very strong spin-dependent polariton-polariton interactions, which already resulted in interesting phenomena such as superfluid-like behaviour, non-equilibrium condensation, vortices and solitons. Giant optical nonlinearity in polariton systems potentially may lead to development of devices of novel functionality for all-optical signal processing.

This project concerns participation in ultrafast optical experiments to study polariton solitons and condensation. You will learn the tricks of fine optical measurements and low temperature techniques. Data analysis will be performed using Matlab or C++.

Design of Optical Microstructures for On-Chip Nonlinear Optical Circuits

Dr D Krizhanovskii (E16) & P Walker

Polaritons are novel 2D quasiparticles, which form in semiconductor microcavities due to strong exciton-photon coupling. Strong optical nonlinearity in polariton systems due to an excitonic component enables the formation of solitons, which are localised non-spreading non-diffracting wave-packets. Potentially solitons can be used in all-optical ultrafast signal processing, since they can be switched on and off on a picosecond timescale, and have well-defined shape and amplitude.

This project concerns the design of optical microstructures for guiding polariton solitons and constructing polariton soliton logic gates. Linear propagation of polaritons in structures of different geometries (Y-splitter/combiner, Mach-Zahnder interferometer etc) will be simulated using available FDTD software. Nonlinear soliton phenomena will also be investigated at a later stage, and a comparison with the experimental observations will be made.

Has Dark Matter been Discovered?

Dr V Kudryavtsev - E45

A few years ago one of the experiments searching for weakly interacting massive particles (WIMPs) expected to constitute the dark matter in the Universe, reported the positive signal from WIMPs. The aim of this project is to investigate whether the claim made by this group is serious by comparing its results with those from other experiments, and to design a new experiment that will be able to test the observed signal.

Students working on this project will study astrophysical and cosmological evidences for dark matter, learn basic principles of WIMP dark matter detection and experimental techniques. At the end of the project students will present their critical analysis of the reported observation of WIMPs and the conceptual design of a new experiment able to test these results.

Designing a Dark Matter Experiment

Dr V Kudryavtsev - E45 & E Korolkova

This project involves Monte Carlo modelling of a future dark matter experiment LZ as part of a large project in the particle physics group. LZ will exploit a two-phase liquid xenon technology for dark matter detection. When designing a high-sensitivity experiment, one of the crucial problems is to ensure a low background rate from various possible sources, including cosmic rays. This project will involve simulations of background radiations for LZ.

This project is suitable for a student with good computational skills.

Muon Tomography for Carbon Storage Monitoring

Dr V Kudryavtsev - E45 & D Woodward

This project is linked to the development of the technology for carbon storage monitoring using cosmic-ray muons. The students are expected to carry out a Monte Carlo modelling for a muon detector positioned in a borehole beneath the geological repository that stores the carbon dioxide.

This project is suitable for a student with good computational skills.

Setting a Limit on WIMP Interactions from a Dark Matter Search Experiment

Dr V Kudryavtsev - E45

A student will be given data from the existing dark matter experiment and will need to convert these data into limits on the cross-section of WIMP interactions with normal matter.

To do this, the student will need to learn the principles of WIMP detection, experimental techniques and data analysis procedures. They will also need to learn the method of calculating limits on cross-sections based on experimental data. The student will write a computer program (in their preferred programming language) that calculates such limits from available data.

This project is suitable for a student with good computational skills.

Temperature Dependent Spectroscopy of Perovskite Semiconductors

Prof. DG Lidzey - D18

Perovskites are a class of solution-processable semiconductors that are generally characterised by a crystal structure ABX3, and are of great interest for optoelectronics, and are a 'hot topic' in condensed matter research. Recently, they have been shown to work with an efficiency that almost matches that of crystalline silicon when fabricated into a photovoltaic device.

At Sheffield, we have a broad programme into the development of perovskite photovoltaics, and in this project you will perform some basic spectroscopy measurements on a series of perovskite materials. In particular, you will measure photoluminescence emission and optical absorption of a range of different materials as a function of temperature from room temperature to 4K. Your objective is to determine whether known changes in the crystal structure are reflected by changes in the absorption or emission spectra, or emission efficiency.

Monitoring the Neutron and Gamma Emission of the Pulsed Neutron Fusion Generator

Dr. J. McMillan - D36a

A technique to monitor the flux of a pulsed neutron generator has been developed using a plastic scintillation detector shielded with a substantial thickness of lead or bismuth. The project will involve optimizing the design of this detector and testing it on the Sheffield generator.

(To make arrangements to discuss this project, contact via e-mail at

Testing Predictions: How Accurate is the Weather Forecast?

Dr. M. Malek - E34b

This is a data analysis project that will utilise an array of statistical tools to evaluate the prediction we experience most: weather forecasts.

You will first decide upon your data sets by choosing which quantities to track. These can include continuous variables (such as temperature) as well as discrete conditions like "sunny", "cloudy", "rainy". You will also select sources of forecasts, ranging from seven to sixteen days in advance.

You will then accumulate your data by charting these ten day forecast for at least a month. These data will be binned into individual calendar days; each day will have entries for each prediction, plus the actual weather as recorded on the day.

Whilst accumulating your data, you will develop your analysis techniques. These can include statistical methods such as linear regression, Kolmogorov-Smirnov tests, and hypothesis tests. With the aid of a literature search, you will also select at least one method to serve as the null hypothesis (e.g., the 'persistence model', which predicts that the weather will stay the same as the current day).

Once sufficient data has been acquired, you will apply the analyses that you have developed. You will evaluate the mean difference and standard deviation of each period of prediction, and you will determine the probability (p-value) we can trust each of your chosen weather forecasts.

Although there is no explicit physics content in this project, the analysis techniques you will learn and use are widely employed in physics research.

Science Communication in Unconventional Settings

Dr. M. Malek - E34b

As creators of knowledge, scientists have an obligation to share what we learn with the general public. This is partly a moral duty and partly a practical, financial one - our research is largely supported by grants that are funded by the taxpayer. In addition to being an important responsibility, science outreach can be fun!

Over the course of this semester, you will design and execute an innovative public engagement project. You will have considerable flexibility in choosing the form and content of the project. Depending on the choice of topic, you may not be required to have the necessary expertise to deliver the science content of this project; however, you will be expected to make arrangements to find a speaker / presenter / etc. who can do so.

You will also have the benefit of my own connections in this area; for example, I recently worked with Physics Unbound, a charity specialising in physics outreach events, to organise a 'Cocktails & Physics' evening in Sheffield. Similarly, in October 2015, I partnered with the Curzon Cinema to organise a 'Back To The Future Day' science evening. Additionally, I am teaching the 'Topical Science' module as part of the Faculty of Science's MSc in Science Communication; you will have the opportunity to speak to students on this course to discuss ideas for your project.

Reconstructing Neutrino Events in a Liquid Argon Detector

Dr. M. Malek - E34b

Liquid argon (LAr) time projection chambers are an emerging technology for neutrino detection, and the heart of the US-based neutrino programme. The argon provides a dense target for neutrino interactions, which produce significant amounts of ionisation and scintillation light for detection. Particle identification is derived from the energy deposited during travel; finely spaced wires combined with digital sampling provides exception resolution.

The University of Sheffield in involved in several upcoming LAr neutrino experiments, including the Short-Baseline Near Detector (SBND) at Fermilab, and ProtoDUNE at CERN. In preparation for these experiments, a strong event reconstruction is required.

For this project, you will work within the LArSoft framework to develop parts of the neutrino reconstruction. Possible areas of focus include electron lifetime estimation, calorimetry cross-checks / calibration, and track matching. You will be aided by the existing efforts in our group, but will be expected to produce your own work. No previous experience with the LArSoft framework is expected; however, strong programming skills will be necessary.

Although not required, this project has the potential to extend into a 4th year project (and possibly beyond).

Developing a New Type of Neutron Detector

Dr. M. Malek - E34b

Neutron detection has a wide variety of applications, ranging from particle physics to nuclear reactor monitoring to nuclear threat reduction. The element with the greatest ability to capture neutrons is Gadolinium, which has a 'cross-section' for neutron capture of 49,000 barns (five orders of magnitude greater than common elements like Hydrogen).

In recent years, particle physics experiments have employed liquid scintillator detectors loaded with Gadolinium, and there has been extensive R&D into using a Gd-water solution. However, another common detection technology - plastic scintillator - has not yet been adapted to work with Gadolinium.

In this project, you will be provided with a set of Gd-lined rods of plastic scintillator. Using optical fibres and photomultiplier tubes, you will be able to detect when light is produced within these rods. Under supervision, you will work with a neutron and gamma source to take data, which you will then analyse. A primary goal of this project will be to distinguish between actual neutron captures and electromagnetic backgrounds (i.e., photons, or gamma radiation).

Teaching Quantum Mechanics in a Macroscopic Classroom

Dr. M. Malek - E34b

When applying to a physics course at university, many A level students write that one of the main reasons they wish to study physics is quantum mechanics. This is unsurprising, as the subject includes strange phenomena not seen in the macroscopic world, including 'God' playing dice with the universe, and 'spooky action at a distance'.

Although a fascinating subject, one of the primary challenges in teaching quantum mechanics is a lack of easy demonstrations. Whereas classical physics lectures benefit from pendula, springs, and spinning bicycle wheels, it is not possible to bring a 'particle in a box' into LT.1 and ask students to measure the uncertainty in its position and momentum. There are inherent physical limitations in studying the microscopic world in a macroscopic classroom.

This project will draw on the quantum mechanics portion of PHY250/251. You will design a series of aids to describe the concepts taught in those lectures. It will be necessary to demonstrate your own understanding of level 2 quantum mechanics as you produce innovative tools to complement the existing lecture series and enhance student learning.

A Prototype Device for Detecting Early-Onset Parkinson's Disease

Dr. M. Mears - D29

Recent work suggests that changes in cerebellar function can be seen through changes to normal muscle control. This project will design and test a prototype device that aims to detect these shifts in muscle tremor, as part of a new collaboration with the Medical School at The University Of Manchester.

Students will not need any particular expertise in experimental work as this initial prototype will be a very simple system. However some experience with LabView would be useful although by no means essential.

Developing a Sperm Count Device

Dr. M. Mears - D29

Infertility affects 1 in 6 couples in developing countries (higher in the developing world) and problems with the male partner are a contributory factor in up to 50% of cases. It is often difficult to begin a diagnosis of male factor infertility due to the embarrassment of speaking to a GP and producing an on-site sample at the clinic.

This project will investigate the potential for a table top sperm counter than can be used by non- specialists or, in the future, available as a home testing kit. The experimental nature of this project will involve the design, development and testing of a light-based detector. No prior knowledge of biology is necessary, as in true physicist style we first consider sperm to be identical spheres in a pure medium.

Phase Transitions of Thin Polymer Films

Dr. M. Mears - D29

Thin polymer films exhibit strange behaviour when going through their glass transition. Unlike the solid to liquid phase transition, the temperature at which glass films vitrify to a molten state depends upon film thickness, polymer size, and thermal history. This project will involve determining the glass transition profile of films using a number of techniques, and modelling this behaviour based upon our current understanding of the phase transition process.

Solving the Problem Solving Problem

Dr. M. Mears - D29

One of the key skills in physics is problem solving, the often-trained ability to be presented with an abstract problem and to construct a logical framework in which to solve, or at least approximate, the problem. However most students are taught in a way that encourages only a surface or rote understanding of the topic - remember this, then repeat it in the exam, then forget all about it. The aim of this project is to develop a resource that can support the development of problem solving skills. It is likely that the project will involve some sort of online resource (videocast, animation, etc) but the specific style chosen can be up to you, within reason of course! You will also need to consider how to test the engagement and effectiveness of your chosen intervention.

Optimizing Image Analysis for Optical Super-resolution Microscopy

Dr N Olivier - F31

Localization Microscopy is a method of optical super-resolution microscopy that relies on the stochastic blinking of fluorophores to record large number of sparse images of a sample. This raw data is then processed, and the individual molecules are localized to reconstruct a high resolution image.

This project consists in improving an existing Matlab code to process raw super-resolution microscopy images, and in particular optimizing the identification of false positives.

Benchmarking High Density Software Super-resolution Microscopy

Dr N Olivier - F31

Localization Microscopy is a method of optical super-resolution microscopy that relies on the stochastic blinking of fluorophores to record large number of sparse images of a sample. This raw data is then processed, and the individual molecules are localized to reconstruct a high resolution image.

This project consists in implementing several high density algorithms (written in Python) and benchmarking them on real data

Dark Matter - Evidence, Main Candidates and Relic Density

Prof. L Roszkowski - E34

The project will consist of three parts. In the first, the students will collect evidence for the existence of dark matter. In the second, they will learn about the main particle candidates for the solution of the dark matter enigma. In the third, they will be expected to estimate the relic density of weakly interacting massive particles by numerically solving the Boltzmann equation which describes the production of a popular class of non-relativistic dark matter particles in the early Universe.

Supersymmetry and the Higgs Boson

Prof. L Roszkowski - E34

The students will examine whether the Higgs boson that has been discovered at the Large Hadron Collider can possibly constitute a hint for physics beyond the Standard Model, in particular for supersymmetric models. Pros and cons will be examined. The students will be expected to numerically evaluate the Higgs boson mass in supersymmetric models and compare it with the measured value.

Development of Liquid Argon Particle Detector Technology for Neutrino Physics

Prof. N Spooner - E23

Liquid argon produces scintillation light when particles like gamma-rays or neutrinos interact in the medium. Reconstruction of such events in 3D then allows a very powerful technique for neutrino physics studies as is being proposed for the up-coming $1B mega-experiment DUNE in the USA. In this project you will participate in development of charge and light readout technology concepts relevant to DUNE using small test liquid argon facilities in the laboratory.

The project best suits a pair of students with strong interest in gaining technical hardware skills in such areas as cryogenics, detector physics, vacuum techniques and optics.

(Requires two students working together.)

Searches for Dark Matter with the DRIFT Directional Detector

Prof. N Spooner - E23

In this project the student will work on real data from the DRIFT experiment that is searching for Weakly Interacting Massive Particles (WIMPs) that likely make up the 90% of matter in the Universe known as Dark Matter. DRIFT records the direction of nuclear recoils induced by the elastic scatter of WIMPs off target nuclei in a low pressure gas detector running in the UK's deep underground laboratory at Boulby, 1.1 km below ground. The task will be to understand and use new analysis computer code to examine current dark matter data taken by the experiment with a view to helping to develop more sensitive techniques for searching for these WIMP particles. This is a software project where the student will learn coding concepts and the physics of gas particle detectors in relation to dark matter searches and particle or nuclear physics.

(Requires two students working together.)

Computer Simulations for the COSINE-100 Dark Matter Search in South Korea

Prof. N Spooner - E23

COSINE-100 is a new experiment just started in South Korea searching for Weakly Interacting Massive Particles (WIMPs) that likely make up the 90% of matter in the Universe known as Dark Matter. The experiment uses sodium iodide scintillator to look for an annual modulation in the flux of particle interactions that likely should arise due to the Earth's orbit around the Sun. The project involves using existing GEANT4 computer simulations to assess the background in the experiment due to natural radioactivity in and around the detector. The student will learn computer programming skills, operation and analysis of results in relation to the physics of dark matter and other particle interactions in matter such as from neutrons and gammas.

(Requires two students working together.)

Efficient Light Extraction from Luminescent Nanostructures in Optoelectronic Applications and Nanoscience Research

Prof A Tartakovskii - E24

Many materials emit light under optical and electrical excitation. This can be used in opto-electronic applications such as light-emitting diodes, and in research, where optical spectroscopy is used to understand the internal structure of nano-materials. Efficient light-extraction from these devices and materials is fundamentally important in achieving energy efficient lighting and displays and in experiments where properties of individual molecules or nano-structures are studied. Here we will consider how this is achieved using many examples ranging from semiconductor quantum wells to novel 2D materials and luminescent molecules.

Principles of Magnetic Resonance

Prof A Tartakovskii - E24

This project aims to simulate the spin-echo experiment in an ensemble of nuclear spins. You will use MATLAB or another programming language for writing the code. First, you will simulate the dephasing of the nuclear spin ensemble, leading to a fast decay of the nuclear magnetic resonance (NMR) signal. You will then computationally apply the spin-echo method (including multiple spin-echo) to simulate the revival of the NMR signal and will find what effect this has on its spectral properties.

Computer Simulation of Particle Orbits in a Circular Storage Ring

Prof L Thompson - E41

The basic equations of motion of a particle in a storage ring can be expressed in matrix form. The project requires a computer program to be written that uses these equations of motion to simulate the operation of a simple storage ring. The properties of the storage ring (e.g. acceptance) as a function of some of the ring's physical parameters such as the ratio of the dipolar to quadrupolar field strength, number of gaps in the ring, etc. are subsequently investigated.

Development of a Peak Finding and Fitting Algorithm for the Treatment of HPLC Spectra

Prof L Thompson - E41

Identifying peaks in data is a common requirement in different experiments, e.g. in performing gamma ray spectroscopy. In this case a number of spectra taken using High Pressure Liquid Chromatography will be used. The task is to write a computer algorithm to locate the peaks in the data and to estimate the size of the peaks. Ideally this should be done with a user friendly graphical interface.

The Computer Simulation of Ray Tracing in a Plastic Scintillator

Prof L Thompson - E41

The aim is to develop a computer simulation of a tile of plastic scintillator to estimate the overall efficiency of the scintillator when a charged particle passes through it. The simulation will need to describe the geometry of the scintillator tile and will consider effects such as reflections and absorption in the material, both of which are wavelength dependant. The simulation will use ray tracing techniques to track the paths of individual scintillation photons to 4 points on the tile where photons are collected, by wavelength-shifting optical fibres, for subsequent transport to a photosensor. The effects of the use of reflective materials to wrap the tile and of refractive index coupling materials in and around the tile-fibre interface on the overall efficiency will also be investigated.

Position Reconstruction in Plastic Scintillator

Prof L Thompson - E41

The project will start with a period of data collection of data from 4 photosensors linked to optical fibres that run through a stack of tiles of plastic scintillator. Data will be acquired when cosmic ray muons pass through the scintillator stack. Once the data have been taken a period of data analysis will concentrate on using the data to attempt to reconstruct exactly where, on the scintillator stack, a cosmic ray muon passed though. This analysis will use chi-squared minimisation methods to calculate a probability for where the muon struck the scintillator and will compare that with knowledge of the actual position to estimate an efficiency for reconstructing the correct position.

The Physics of SCUBA Diving

Dr T Vickey - D26

The student selecting this project will get to explore the physics associated with diving. The project will focus on one or more physical principles such as pressure, buoyancy, sound and/or light, and these will be explored in depth and in a quantitative way. Computer simulations will be used by the student to explore theoretical concepts and explain (quantitatively) what one experiences while diving.

Semiconductor Detectors in Particle Physics

Dr T Vickey - D26

The students selecting this project will review the concepts behind silicon detectors and the importance of their role in active collider experiments. There will be an opportunity for some hands-on work with silicon detectors in the new Sheffield Semiconductor Detector Facility (SSDF) in the Department of Physics and Astronomy.

Dielectric Multilayers

Prof. D Whittaker - E12B

High reflectivity Bragg mirrors are made from alternating layers of dielectric materials, with high and low refractive index. By altering one of these layers, it is easy to make a cavity which traps light in the structure. In this project, you will use the transfer matrix method to calculate the properties of dielectric multilayers, and investigate different types of cavity design. Many of the concepts involved are directly analogous to the electronic band structure theory which will be studying in PHY330.

Lorenz Waterwheel

Prof. D Whittaker - E12B

The Lorenz waterwheel is a nice example of a chaotic mechanical system (it is, in fact, related to a model of convection in the atmosphere). Under the right flow conditions, from time to time it will change its direction of rotation. The aim of this project is to build a waterwheel, and study enough chaos theory to understand why it behaves as it does.

The Upside-Down Pendulum

Prof. D Whittaker - E12B

A simple pendulum is in stable equilibrium only when it hangs vertically below its pivot. It also has an unstable equilibrium, with the bob vertically above the pivot. However, this vertically up position can be made stable if the pivot oscillates up and down at a suitable frequency. The aim of this project is to model this effect on a computer, and build a physical pendulum to investigate the stability which is obtained.