Summer Internship Programme 2021

Oxford Particle Physics will run a Summer Internship Programme for undergraduate physics students. We anticipate taking about 6 students. Priority will be given to students in their second year and above.

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, discussions and seminars (currently taking place virtually).

The projects run for typically 8 weeks, nominally 5 July through to the end of August. Students will be paid as employees of the University, receiving a payment of £10.31 per hour (subject to tax and National Insurance deductions). The project is normally full-time but hours can be discussed with your supervisor. Projects are likely to be remote, but we will evaluate the possibility to have in person if possible.

Eligibility

Applications are welcome from students at institutes outside of Oxford. Unfortunately, due to UK visa regulations, we are only able to accept applications from candidates who do not require a visa to work in the UK. Note that from January 2021, this will also include students that live in the EU. EU students currently studying in the UK who have obtained Pre-Settled status are also welcome to apply. If you have queries about your personal circumstances, please get in touch with sue.geddes@physics.ox.ac.uk

How to apply

You should email a one-page-only application, in pdf format, to Sue Geddes (sue.geddes@physics.ox.ac.uk) by Monday of 1st week, 26 April 2021. Students should ask for a short academic reference letter to be emailed by the same date. Offers will be made in mid May 2021.

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

Detector performance studies for SNO+

Supervisor: Professor Steven Biller (steve.biller@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 has been replaced with liquid scintillator to provide unique sensitivity to a wide range of fundamental physics, including a search for neutrinoless double-beta decay with 130Te. The experiment has just completed transition from water to scintillator and is now fully operational and preparing for the introduction of 130Te next year. This project will therefore involve working with data and simulations to help assess the detector performance in this new mode with regard to event reconstruction and background levels. There will also be an opportunity to contribute to some prototype work on new liquid scintillator technologies.

The CERN Linear Electron Accelerator for R&D

Supervisor: Professor Philip Burrows (philip.burrows@physics.ox.ac.uk)
Duration: 8 weeks

The CERN Linear Electron Accelerator for R&D – has been commissioned and experiments are taking place on the beamline. The intern will have the opportunity to work on simulation studies for operating and upgrading the 220 MeV electron beamline. There are also opportunities for working on simulations of novel beam position monitors and high-gradient radio-frequency accelerating cavities.

Visualisation of neutrino oscillations

Supervisor: Dr Lukas Koch (lukas.koch@physics.ox.ac.uk), Dr Xianguo Lu (xianguo.lu@physics.ox.ac.uk)
Duration: 8 week

The software program VISOS(VISualisation of OScillations) is a project to illustrate neutrino oscillations. Its primary goal is to precisely explain this beyond-Standard-Model physics to the general public in an intuitive manner. It also has an attractive potential to help researchers in the field explore the phenomenology of neutrino oscillations in different parameter space. It is available online:

http://www-pnp.physics.ox.ac.uk/~luxi/visos/

In this project the student will improve the web application of VISOS.
One target is to enable users to easily create animations/videos of the simulations and save them for later use. For this the student will learn the use of state-of-the-art plotting and visualisation tools. This project requires a good understanding of web technologies and programming skills. A strong interest in neutrino physics is advantageous but not required.

Charming physics

Supervisor: Dr Sneha Malde (sneha.malde@physics.ox.ac.uk)
Duration: 8 week

Modern flavour physics measurements are complex beasts often reliant on some external or previous input or data driven calibration from data involving charm mesons. Improving our knowledge of these key inputs is important and can have high impact across a range of other studies. The project will focus on the analysis of real experimental data and will be computer based. The project will involve identifying charm signal decays of interest and determining the contaminating backgrounds that remain after selection. Simulated data will be studied to determine lineshapes and detection efficiencies, and these will be applied to the data to determine the signal yields through a fitting procedure. These yields will then be interpreted in terms of branching fractions or detection efficiencies depending on the decay channels pursued. The data will come from either the BESIII or the LHCb experiment.

PaMIr+: Interferometry on fast targets

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

The PaMIr team is very happy to offer a range summer project topics suitable for both remote and local participation during the summer vacation 2021. At most one of these projects can be funded through the department’s summer placement funds.

Scope of the summer projects
PaMIr is short for Phase Modulation Interferometry. The PaMIr group is developing a novel method to interferometrically measure rapid displacements with high accuracy and time resolution as well as low latency on a large number of interferometers simultaneously.

PaMIr+ summer placements will help to extend the PaMIr scope in two ways:

  1. To link the displacement to absolute distance measurements made with our own Frequency Scanning Interferomerty systems (FSI).
  2. To develop a portable, standalone single channel solution of PaMIr

Background of the PaMIr project
PaMIr is designed to become a plug-compatible extension to our FSI technology which is now used in its commercial form (Absolute Multiline™) in many scientific projects in accelerator science, particle physics, astrophysics and many industrial settings. Our technology already has applications in many large-scale science experiments. Among them are the alignment of the crab cavities in the upgrade HL-LHC, control of undulators at LCLS-II (Linac Coherent Light Source at SLAC), relative positioning of the primary and secondary mirrors of several next generation telescopes (GMT, EELT, KECK), as well as future measurements of deployable space antennae on satellites.

The high speed, continuous differential measurements from PaMIr can be used in dynamic control loops to measure rapidly time variable positions continuously over long periods. These are needed in many of the above science problems and in the control of robots and CNC production machines in industry which play a huge role in our societies.

The project and the group
The PaMIr project is funded through an innovation partnership grant, which has inputs from STFC and from our two industrial partners, VadaTech Plc and Etalon. The prospective summer students will become temporary members of the PaMIr group, which currently has five members at Oxford. Prof Armin Reichold (group leader), Dr Peter Qui (PDRA), Dr Jubin Mitra (senior FPGA engineer), Mr Mark Jones (analogue electronics engineer), Mr Rui Gao (FPGA engineer) and Mr Johan Fopma (Head of physics electronics engineering). We have enjoyed input from four summer students and an MPhys student to date who have been great contributors to our research. Seven further part time team members are working on the project in our partner organisations.

We are also collaborating with Prof Jonathan Huntley, Prof Pablo Ruiz and Dr Christos Pallikarakis from the University of Loughborough on aspects of frequency standards for FSI using data we took from the national institute of standards in Germany (PTB).

Summer placement opportunities 2021
This summer student opportunity offers a wide range of possible engagements with the PaMIr project. The activities suitable for a summer student fall into two broad categories and are listed below.

  1. PaMIr Measurements, Simulations and Analyses
    • Setting up a new fast motion stage system based on pneumatic actuators
    • Simultaneously measuring displacements with PaMIr and 4 other reference instruments (already set up)
    • Analysing PaMIr and reference instrument data with multiple algorithms and comparing them.
    • Determining the performance of PaMIr as a function of laser power
    • Comparing the performance of PaMIr with different stabilised lasers
    • Measurement with PaMIr at so called “critical distances”
  2. Extensions of Frequency Scanning Interferometry
    • Analysis of gas-cells absorption spectra and frequency comb measurements
      1. Fitting gas absorption cell spectra with Voigt-Functions
      2. Evaluating the accuracy of the above fits by comparison with the frequencies from a high precision frequency comb.
      3. Accelerating the above fits by porting them to a GPU using MATLAB’s GPU compute facility or the CUDA package.
    • Testing methods for the combination of FSI and PaMIr through simulations.

Requirements
The underlined projects above require access to the laboratory.
All other projects are suitable to some degree for a remote project if access to a well-functioning remote computing set-up and network connection is available to the student.

Work in the PaMIr group requires an understanding of second year wave optics, in particular lasers and interferometry.

General computer skills are also required for all of the above projects.

Skills useful for all of the above projects are a genuine interest and ideally some experience with programming in Matlab and/or C/C++ as well Git. For the lab work, skills in setting up optics and opto-mechanics will be beneficial

Preparing a Project: Tagging B hadrons in High energy jets

Supervisor: Professor Todd Huffman (todd.huffman@physics.ox.ac.uk
Duration: 8 weeks

The B hadron is the bound state of the bottom quark and one or more of the other, lighter quarks in the Particle Physics pantheon. It is often a “gateway particle” into more exotic areas of Physics because both top quarks and Higgs bosons predominately decay into b quarks which will eventually produce a B hadron within a jet of particles.

All B hadrons have a substantial lifetime of around 1.5 ps. This is sufficient to permit a slew of jet identification methods for the ATLAS experiment at the Large Hadron Collider. When a B hadron candidate is found within a jet of particles it is then labeled a b-jet, or the jet is said to have been “b-tagged”.

The ATLAS experiment uses many different methods of tagging and wraps them all up using a feed forward neural network called “DL1r” to generate a “score” which is used to determine if a jet is a b-jet, a light-jet, or a jet containing a charm quark progenitor. But this tagger tends to lose efficiency for b-jets, and has trouble rejecting light-jets, when the jet energies become large …meaning greater than 500 GeV.

One reason for this is the B-hadron’s lifetime is long enough, and the ATLAS energy is high enough, that Lorentz factors in excess of 100 are now not uncommon. Such B hadrons would survive long enough to decay within the detector itself. Further their energies would be so high that the hits in the pixel detector would cluster tightly. This property makes it difficult for all traditional methods of detecting b-jets.

The possibility that the hit numbers would “jump” from one layer to the next, because of a B decay, or that the hit clusters would be unique for B decays might well be a method that the neural network could employ to recover light-quark jet rejection and b-jet identification with the highest energy jets produced by the CERN Large Hadron Collider in the ATLAS experiment. The project would seek to study these effects by studying hit-based variables and then applying them to the DL1r neural network in order to uncover whether there is merit in this idea for b-jet tagging in the ATLAS experiment.

However, in order to offer an Oxford-style MPHYS project, preparation is needed. The data needs to be prepared and formatted. A suitable computing platform needs to be established and tested. And critically, documentation needs to be either copied or written such that the Oxford project student, can actually have the resources available to start the project. It is also necessary to take the project through several “test runs” to see how it works, and indeed, whether it would work well at all.

Below is a non-ordered list of what needs to be done over the summer:

  • Monte Carlo (MC) data run and the code needed to keep any variables of interest secured, understood, and tested.
  • Training and testing and then independent MC samples so prepared.
  • Data preparation steps documented for the project student.
  • Example feed-forward Neural Net dusted off and prepared for the pplxint machines.
  • Confirmation that default NN, when trained with the standard inputs, largely reproduces the expected results previously obtained for the jet energies in our MC samples.
  • Run through training and testing steps of NN with hit-based inputs as well as standard inputs to determine if improvements are on offer.
    • While doing this, fix bugs and document how to operate the code and how to generate the plots.
    • Do some research into different inputs, different NN internal configurations. In other words, find out if this will work and if it works well enough to be used as a project.
    • Explore how difficult the learning curve is to this process an what might be improved, then improve it if possible.
  • Produce a “Guide” or an equivalent to a “lab script” for this project to aid the student who will try it next term.