Summer Placement Programme 2017

Oxford Particle Physics is running a summer placement programme for undergraduate physics students. We anticipate taking about 18 students. Priority will be given to students in their second year and above. Unfortunately we cannot take students from outside the EU unless you already have a work permit.

Students will work with a supervisor in the department, usually a postdoctoral researcher or lecturer, on a self-contained project. Students are encouraged to take part in department life, joining researchers for coffee and discussions.

The projects run for typically 8 Weeks during the Oxford summer vacation. Students will be paid a subsistence of £230.00 per week. The project is full-time but hours can be discussed with your supervisor.

Applying

You should email a one-page-only application, in pdf format, to Sue Geddes (sue.geddes@physics.ox.ac.uk) by Sunday of 1st week, 23 April 2017. Students should ask for a short academic reference letter to be emailed by the same date. Offers will be made in mid May 2017.

On your 1-page application you should tell us why you are interested in the programme and which project(s) most interest you. Also include your contact details, your year and course, and contact details (including email) of your academic referee. Please also mention any computer programming experience and any previous research experience that you have had.

You are welcome to informally contact the supervisor(s) to find out more details about the projects that interest you. For any administrative issues, contact Sue Geddes (sue.geddes@physics.ox.ac.uk).

Projects

Longitudinal profile reconstruction of femtosecond electron bunches

Supervisor: Dr Ivan Konoplev (ivan.konoplev@physics.ox.ac.uk)
Duration: 8 weeks

Imaging of the longitudinal profile of femtosecond electron bunches is key to successful implementation of the next generation of state-of-the-art accelerators and their application for generation of coherent X-ray radiation. There are number of imaging techniques based on spectral analysis of coherent radiation generated by the electron bunches, but difficulties with the stability of the solutions (i.e. the uniqueness of final 1D image) are still present, especially for a bunches with complex shapes.

The project will develop a method to optimise the number of observations and their target frequencies to enable measurement of the longitudinal beam profile to a specific accuracy. The studies will be conducted using analytical and numerical models as well as spectral data observed at FACET, SLAC (Stanford University, USA). The proof of algorithm validity will be important part of this research project, as will the optimisation of the relevant numerical models.

The knowledge of programming techniques (MATLAB, Python, C) and mathematical methods (Fourier analysis, Complex function) is desirable for this project. The researcher will be working in team and it is expected to have a good communicational skills. It is expected that if the project is successful it will potentially lead to publication in one of the physics journals.

Study of asymmetric, dual-axis cavity for Energy Recovery LINAC

Supervisors: Dr Ivan Konoplev (ivan.konoplev@physics.ox.ac.uk) & Professor Andrei Seryi (andrei.seryi@physics.ox.ac.uk)
Duration: 8 weeks

High-brightness, intense sources of coherent X-ray radiation are extremely useful tools in science and used to probe matter of different kinds and in different states. These radiation sources are usually driven by particle accelerators such as synchrotrons and free electron lasers, vital tools which exist at only a few national laboratories around the globe. The size and energy consumption of such particle accelerators are key reasons for the restricted number of facilities and there are number of projects undergoing to develop more compact and affordable electron beam drivers.

This project is a part of a larger initiative to develop compact, superconducting, RF driven, high current energy recovery linear accelerator (LINAC). Such a LINAC can be used to generate high intensity X-Ray of properties comparable with radiation observed at large synchrotron or FEL facilities. The one of the main challenges of the project is to control and suppress high order modes inside accelerating/decelerating structures, which will be excited by the high current beam. These modes could interfere with the energy recovery and could potentially interrupt the beam transportation through the system. The main tasks will be development of a numerical model using CST microwave studio and experimental mapping of the field inside the cavity using equipment available in the RF laboratory.

The outcome of the project will contribute to the current UH-FLUX research program on development of compact source of coherent radiation. It is expected that the student who will take on this project is familiar with computer codding (MATLAB, C, Python) and EM theory. The researcher will be working in team with senior colleagues and good communication skills are expected. If the project is successful it may lead to a publication and good writing skills will be beneficial.

Selection of D(s)+ mesons in the π+π0 final state

Supervisor: Dr Malcolm John (malcolm.john@physics.ox.ac.uk)
Duration: 8 weeks

A charged D(s)+ meson is a bound state containing a charm and down-type quark. It decays to two strangeless mesons with a with a branching fraction up to 2%. Due to the very large charm production cross section at the LHC, millions of such decays occur each year but triggering on them is extremely challenging due to the lack of a vertex in this decay. However, it has recently been demonstrated (in unpublished work) that a signal is seen where the π0 meson is reconstructed in the rare eeγ 'Dalitz' final state. Such is the rate of charm production at the LHC, that LHCb now has on tape the largest sample of these decays ever reconstructed despite the low efficiency of the chosen decay mode.

In this project the student will derive an offline selection using preselection samples already made by the collaboration's central data processing. The student will need to understand all the physical characteristics related to this decay, comparing real data with simulation. The student will be expected to compare a simple cut-based selection and devise a competitive result using machine-learning algorithms. The project demands curiosity, interest and tenacity. Programming experience is useful but not expected. If the successful applicant is an Oxford undergraduate, the project would transfer well into a MPhys project.

Measuring the W boson mass

Supervisor: Dr Mika Vesterinen (mika.vesterinen@physics.ox.ac.uk)
Project duration: 8 weeks

Our current understanding of the fundamental constituents of matter, and the forces between them, is encapsulated in the Standard Model theory. It provides a remarkable resemblance of the behaviour that we observe in particle physics experiments. Yet it is known to be at best a low energy approximation of a more complete theory.

The CERN LHC is intended to uncover the next layer of fundamental physics.
A promising approach is to make ultra-precise measurements that can be compared to the predictions of the Standard Model. For example the Standard Model asserts a relationship between the masses of the W boson, Higgs boson, and top quark, which results from Quantum loop effects.A measured deviation from this prediction could indicate Quantum loops involving heavy new particles from beyond the Standard Model.
The sensitivity of this fundamental test is mostly limited by the precision with which we have been able to directly measure the mass of the W boson. This project will develop a method with which to measure the W boson mass using data from the LHCb experiment.

The student will devise methods which allow the W boson mass to be determined with the highest possible precision, by comparing real LHC collision data with theoretical simulations. They will develop computer software to perform this analysis. Reduced datasets for this purpose have been prepared at CERN, and stored on a local computer cluster in Oxford.

Beam studies for the Compact Linear Collider (CLIC) at CERN

Supervisor: Professor Phil Burrows (phil.burrows@physics.ox.ac.uk)
Duration: 8 weeks, starting date ideally around 26th June

The new CLEAR facility – CERN Linear Electron Accelerator for R&D – is being commissioned and first experiments will take place in 2017. The intern will have the opportunity to work on both hardware and simulation studies for setting up and operating the new 220 MeV electron beamline.

Absolute distance interferometry using a frequency comb

Supervisor: Dr Armin Reichold (armin.reichold@physics.ox.ac.uk)
Duration: 8 weeks

Frequency scanning interferometry is a technique for absolute distance measurements. In the incarnation referred to as dynamic FSI, developed at Oxford physics, it relies on the ability to measure the frequency of scanning laser using absorption spectroscopy on molecular excitations of gases such as acetylene or hydrogen cyanide. This technique has already generated a patent and four commercial licenses and is currently implemented as an industrial precision instrument (Absolute Multiline) through the German company Etalon AG.

In 2015 FSI measurements were made by Oxford Prof Armin Reichold at the German national institute of standards (PTB) in Braunschweig in which in addition to multiple gas absorption cells and a precision reference interferometer a state of the art, high precision frequency comb was used to record beat-patterns of the scanning lasers with the comb laser. This data has not yet been analysed and has a high potential to enable new ways for improving the spectroscopic methods used in FSI and hence improve the distance measurement accuracy.

This summer projects purpose will be to analyse the data with extensions of existing JAVA codes and/or new MATLAB codes in a variety of ways among which could be:

  1. Fitting the beat signals of the scanning lasers with the comb to obtain a highly precise frequency axis.
  2. Fitting the positions and widths of the peaks in the absorption spectra with Voigt functions instead of the simpler Gaussian functions used so far.
  3. Potentially performing the fits from 2. using a total chi-squared method in which errors in both axes can be considered.
  4. Comparing the results of the above fits to see how accurately the Gaussian fraction of the width of the peaks can be fit and hence how accurately the pressure of the gas cell can be determined.
  5. Comparing the results of the above fits to measure the relative spacing of the gas cell peaks
  6. Using these results to improve the distance measurement results.

The project is open ended and the data has not been analysed before. How many of the above points can be dealt with depends on the student and on the data. The data analysis aspects demand good analytical skills and good programming skills with some experience in Java preferred because the majority of existing analysis code is in Java.

Depending on the preferences of the students this project could also be directed towards the hardware aspects of the FSI technique. The full hardware for the above experiments (except for the frequency comb) is now available in Oxford together with a new high speed data acquisition system which can extend the capabilities of the technique significantly. Students with a desire to work more on the hardware side of this technique could participate in this aspect.

Novel laser polarisation state generation for particle acceleration

Supervisor: Dr Laura Corner (laura.corner@physics.ox.ac.uk)
Duration: 8 weeks

Recent experiments have shown that it is possible to directly accelerate electrons by tightly focusing radially polarised laser beams. These are usually created with expensive specialist optics that produce imperfectly polarised beams. We have opportunities for a summer student to work on generating these polarisation states directly from fibre lasers by a novel method of combining higher order spatial modes in fibre amplifiers. This project is predominantly experimental and would suit an independent student who is interested in lab work, but the project will also involve the theory and numerical modelling of these polarisation states and their properties.

A Flexible Algorithm for Online Optimisation of Particle Accelerator Performance

Supervisor: Professor Riccardo Bartolini (riccardo.bartolini@physics.ox.ac.uk)
Duration: 8 weeks

The overall performance of the electron storage ring is critically dependant on a large number of machine parameters. This performance can be characterised in a number of different ways, such as by measuring electron beam lifetime, transverse stability, injection efficiency, injection transients, instability thresholds and so on. However, it is frequently the case that improving one parameter comes at the cost of harming another. Similarly, given the large number of variables involved in optimising the ring performance, the true, global optimum solution may be difficult to identify using simple parameter scans. In order to address this problem, a flexible optimisation tool is required. This tool should be capable of optimising several parameters at once, using an arbitrary number of variables to achieve this goal (typically the strength of various magnets). It should be possible to apply the tool to any online optimisation problem, and not tied to any particular set of optimisation variables. The tool should also be able to cope with measurement noise on the parameters to be optimised.The main outcome of the project will be a fully-documented optimisation package (e.g. Matlab or Python) that can be used as a flexible tool in the Diamond control room. The project includes the investigation into existing genetic algorithms (e.g. Multiple-Objective Genetic Algorithms) and their benchmark and use in the optimisation of the Diamond storage ring with a series of dedicated experimental sessions.

The main benefits for the student include gaining knowledge and expertise in the fields of accelerator physics, numerical optimisation and software development. The student will develop communication skills through presenting the status of their work at regular group meetings. In addition, the student will have the opportunity to participate in machine studies of the existing Diamond accelerators.

Desirable criteria for applicants:

  • Good general physics knowledge
  • Good mathematical ability
  • Experience with using Matlab or Python

Constraints on Supersymmetric Dark Matter from recent LHC measurements

Supervisor: Professor Alan Barr (alan.barr@physics.ox.ac.uk)
Duration: 8 weeks

The make-up of dark matter is one of the outstanding problems of physics today. The world’s highest-energy collisions at the LHC have the potential to produce dark matter in the laboratory for the first time. This project will use very recent results from the LHC to constrain the parameters of leading models of Dark Matter. The methodology involves Monte Carlo simulation, high-performance computing and statistical interpretation. The project will be supervised by Prof Alan Barr, with further input from an existing Oxford graduate student who has also recently published in this field. If new insights are found, a further journal publication may result.

Simulation study of neutrino interactions in an argon gas TPC

Supervisors: Dr Justo Martin-Albo (justo.martin-albo@physics.ox.ac.uk) & Professor Alfons Weber (alfons.weber@stfc.ac.uk)
Duration: 8 weeks

Next-generation neutrino oscillation experiments, in order to meet their physics goals, will require a significant increase of our understanding of neutrinointeractions. In particular, nuclear effects such as nucleon correlations or final-state interactions introduce significant confusion and biases in the event reconstruction that result in large systematic uncertainties. Additional experimental data aretherefore required to clarify these issues and improve our current models describing neutrino-nucleus interactions. A gaseous detector offers unique capabilities for such a task: it can provide a high-resolution measurement of the charged tracks emitted from the neutrino interaction vertex, including, thanks to its low detection thresholds, those in the low energy region in which the differences between model predictions are most pronounced. The selected student would be expected to carryout Monte Carlo detector simulations, analyse their output and interpret the physics results. Candidates with interests in experimental particle physics, and/or particle physics phenomenology are encouraged to apply. Basic programming skills a and acquaintance with undergraduate-level nuclear and particle physics is preferred.

Improving Hadron Measurements in MINERvA Experiment

Supervisors: Dr Xianguo Lu (xianguo.lu@physics.ox.ac.uk) & Professor Alfons Weber (alfons.weber@stfc.ac.uk)

In future long baseline neutrino experiments, neutrino-nucleus interactions are used to measure neutrino properties with extreme precisions. One major systematic uncertainty in measuring the neutrino energy and the interaction cross sections---the two ingredients for a neutrino energy spectrum---comes from nuclear effects inherent in the interaction targets. For a better understanding of these effects, precise measurements of the final-state particles in neutrino-nucleus interactions have become exceedingly important. The MIENRvA Experiment in the US is a world leading experiment measuring neutrino interactions; while novel analysis methods are proposed, its performance beyond design is being pursued. This project focuses on developing new approaches to improve its hadron measurements, with the prospect to provide critical implications for future experiments.

The successful candidate is expected to analyse experimental data and to develop new methods to improve the sample quality for hadron kinematics. Candidates with interests in experimental particle physics, particularly in detector physics, are encouraged to apply. Basic programming skills and acquaintance with undergraduate-level nuclear and particle physics is preferred.

Model Study of Nuclear Effects in Electron-Nucleus Interactions

Supervisors: Dr Xianguo Lu (xianguo.Lu@physics.ox.ac.uk) & Professor Alfons Weber (alfons.weber@stfc.ac.uk)
Duration: 8 weeks

In future long baseline neutrino experiments, neutrino-nucleus interactions are used to measureneutrino properties with extreme precisions. One major systematic uncertainty in measuring the neutrino energy and the interaction cross sections---the two ingredients for a neutrino energy spectrum---comes from nuclear effects inherent in the interaction targets. Novel methods have been developed to study such effects [arXiv:1512.05748, 1507.00967]. This project explores the universality of these methods and investigates the possibility to apply them to electron-nucleus interactions to study nuclear effects with high precisions. The prospect of the project is to provide theoretical predictions for electron test beam measurements that are being prepared for future experiments.

The successful candidate is expected to carry out Monte Carlo simulations, to analyse the output, and to interpret the physics results. Candidates with interests in experimental particle physics, and/or particle physics phenomenology are encouraged to apply. Basic programming skills and acquaintance with undergraduate-level nuclear and particle physics is preferred.

Improvement of beam delivery systems for proton therapy

Supervisors: Dr Suzie Sheehy (suzie.sheehy@physics.ox.ac.uk) & Professor Frank Van den Heuvel (Oncology)
Duration: 8 weeks

Proton therapy is a precise form of radiotherapy using protons instead of X-rays. It holds great promise for hard to reach tumours and for childhood cancers, but requires a room-sized particle accelerator and a system of beamlines connecting to a gantry; a beam line that rotates 360 degrees around the patient. Not surprisingly, this system is large and quite expensive. In the future, one way to make this therapy more accessible will be to improve the cost, size and flexibility of the gantry, independent of the accelerator technology. In this project, the student will review existing gantry technologies and future requirements in collaboration with Oncology and then use an accelerator design code 'MAD-X' from CERN to model a new type of gantry based on fixed field magnets. This project would suit a student who is interested in particle accelerators and medical applications of physics. Some programming experience would be beneficial.

Lattice for the Future Circular Collider Hadron-Hadron (FCC-hh)

Supervisors: Professor Andrei Seryi (andrei.seryi@physics.ox.ac.uk) & Professor Emmanuel Tsesmelis (CERN)
Duration: 8 weeks

The aim of the studentship is to complete a project for the Future Circular Collider Hadron-Hadron (FCC-hh) Study.

The FCC Study is developing options for potential high-energy frontier circular colliders at CERN for the post-Large Hadron Collider (LHC) era. It has been launched as a result of the recommendation made in the 2013 update of the European Strategy for Particle Physics.
A description of the FCC in general is available at: https://espace2013.cern.ch/fcc/Pages/default.aspx
The principle parameters of the FCC-hh study are available at https://espace2013.cern.ch/fcc/Pages/Hadron-Collider.aspx

The objective of the project is to study the FCC-hh machine lattice for both a ring design and racetrack design. Starting from existing lattice designs, the project will develop a MAD-X simulation to calculate and optimise the parameters of beam dynamics and beam optics of the machine. The MAD-X software is a computational physics tool used in the field of particle accelerator design and simulation. The MAD-X scripting language is the de facto standard to describe particle accelerators, simulate beam dynamics and optimise beam optics.

Probing naturalness with Higgs measurements

Supervisor: Dr Chris Hays (chris.hays@physics.ox.ac.uk)
Duration: 8 weeks

This project will focus on Higgs measurements sensitive to new particles that can solve the naturalness problem (i.e., why the Higgs mass is at the electroweak scale when loop corrections should give it a much larger mass). Using supersymmetry as a concrete example, Monte Carlo samples will be generated for a range of the allowed parameter space. The Monte Carlo will then be used to identify the distributions most affected by the presence of the stop quark loop in Higgs boson production (i.e., the loop that solves the naturalness problem in supersymmetry).

Designing the Pixel Camera for the ATLAS upgrade

Supervisors: Professor Daniela Bortoletto (daniela.bortoletto@physics.ox.ac.uk) & Professor Ian Shipsey (ian.shipsey@physics.ox.ac.uk)
Duration: 8 weeks

The ATLAS experiment is designing a pixel camera for the upgrade to the Large Hadron Collider. Join an experienced team of physicists and engineers constructing and modifying CAD solid models and mechanical drawings for the camera. A person with experience in AutoCAD in particular Autodesk Inventor Professional 3D CAD software is preferred.

CMOS sensors for the ATLAS upgrade

Supervisors: Professor Daniela Bortoletto (daniela.bortoletto@physics.ox.ac.uk) & Professor Ian Shipsey (ian.shipsey@physics.ox.ac.uk)
Duration: 8 weeks

The ATLAS group has quite a number of CMOS sensors that will need to be tested and understood. CMOS sensors have the basic amplifier and data processing electronics built into the sensor itself and all of it laid out on the same silicon wafer. We are evaluating them to see if they can be suitable to use in the next ATLAS upgrade planned for 2022. A student need have only minimal programming experience but of course, anything might be useful. Much of the work will take place in the new OPMD clean room in the Hooke Building.

Understanding Pixel Module performance for the ATLAS upgrade

Supervisors: Professor Daniela Bortoletto (daniela.bortoletto@physics.ox.ac.uk) & Professor Ian Shipsey (ian.shipsey@physics.ox.ac.uk)
Duration: 8 weeks

The ATLAS group will be assembling pixel sensors for use in the ATLAS upgrade and must understand process control and the system level issues and performance of the full pixel sensors that are made in the OPMD facility in the Hooke building. The project involves helping with the construction and testing of pixel sensors in order to develop the capability to produce them en-masse for the ATLAS upgrade project. These sensors would be used in the LHC for the 2022 upgrade to the ATLAS detector.

Simulation and analysis of data from the initial water phase of SNO+

Supervisors: Professors Steve Biller (steven.biller@physics.ox.ac.uk) & Armin Reichold (armin.reichold@physics.ox.ac.uk)
Duration: 8 weeks

The SNO+ experiment builds on the highly successful Sudbury Neutrino Observatory, which found the first unambiguous proof of neutrino flavour transformation. In this new project, the central volume of heavy water will be replaced with liquid scintillator to provide unique sensitivity to a wide range of fundamental physics, chief among these being a world leading search for neutrinoless double beta decay using 130Te loaded into the scintillator volume. The experiment has just completed the initial water-fill and is in the process of taking, processing and analysing data in preparation for the transition to scintillator, which will take place over the summer. The selected student would be expected to carryout Monte Carlo detector simulations, analyse their output and interpret the physics results. Some chemistry work related to scintillator development for future phases may also be possible. Candidates with interests in experimental particle physics, and/or particle physics phenomenology are encouraged to apply. Basic programming skills and acquaintance with undergraduate-level nuclear and particle physics is preferred.