Thesis Topics

Below is a list of potential thesis topics for students starting in October 2021. We have a number of STFC studentships to use on topics of our choice.

Students with other funding are welcome to apply for any of the listed topics.

Running Experiments:

ATLAS

The New Energy Frontier

During 2015-2018 the LHC delivered proton-proton collisions at record-breaking energies and luminosity. We now are producing Higgs bosons in large numbers, allowing us to enter the "precision era" of Higgs physics. Precision measurements of Higgs properties will be performed to seek evidence for physics beyond the Standard Model. Our sensitivity to the production Dark Matter and other exotic particles is also better than it has ever been before. For us this is a very exciting time, with great opportunities to discover new particles, to test theories and to explore nature at smallest scales with the most powerful accelerator in the world. The period 2019-2020 will be an exciting one, as we explore the energy frontier, and prepare hardware, software and analysis improvements for the major detector upgrades planned for the years ahead.

The Oxford ATLAS group has a world-leading physics program with major responsibilities in the areas of:

Our Research Activities

The ATLAS detector ran successfully during LHC operations and recorded roughly 140/fb of proton-proton collision data which has not all been analysed yet. Major responsibilities of the Oxford ATLAS group include:


Thesis Topics

New PhD students are expected to work in a combination of the above areas. Each of our students spends one year or more at CERN.
ATLAS D.Phil supervisors are Alan Barr, Claire Gwenlan, Chris Hays, Todd Huffman, Richard Nickerson, Georg Viehhauser, Daniela Bortoletto, Ian Shipsey and Tony Weidberg.

Potential graduate students are encouraged to contact supervisors if they have any questions with regard to the thesis topics.

LHCb

B physics and CP violation at the LHC at CERN

LHCb makes precision studies of CP violation in the decays of beauty and charm hadrons ('heavy flavour physics') at the CERN LHC. LHCb searches for physics beyond the Standard Model by investigating departures from the unitarity of the CKM matrix and checking whether or not this provides a consistent picture of observed CP-violation. The experiment also has high sensitivity to new physics effects by looking for enhanced rates of heavy flavour decays that are otherwise very rare in the Standard Model, or in unexpected angular distributions of such decays.

The LHCb detector has already collected a wealth of data, the analysis of which will likely form a significant fraction of the doctorate work. The detector is currently being upgraded, coming online in 2022, and which will greatly increase the data collection rate. Major responsibilities of the Oxford group are on the Ring Imaging Cherenkov (RICH) counters and Vertex locator (VELO); the RICH detectors provide particle identification of pions, kaons and protons over the momentum range from 1 to 100 GeV/c, and the VELO reconstructs B-decay vertices to a precision of around 150μm. The group also leads efforts on the particle identification calibrations that are core to the real-time analysis strategy that LHCb are adapting for the start of data taking.

A new graduate student would be expected to work on a combination of the following areas:

• Undertake a significant data analysis; the Oxford LHCb group has broad physics interests which include CP violation, b-hadron decays involving tau leptons, rare B hadronic decays, charm mixing, electroweak physics including a measurement of the W mass, and central exclusive production. A major topic of the group is the measurement of the CKM angle gamma, with special interest in the family of channels B→ D(*)0 K(*) with the D0 decaying into 2-, 3- and 4-body final states. We are also active in searching for very rare beauty and charm channels, including the B→ Dµµ family of decays. A new student could expect to work in any one of the above areas, or develop an alternative analysis effort which is commensurate with the general interests of the group.

• Participate in the commissioning and operation of the RICH or VELO sub-systems, monitoring the performance of the detectors and their readout systems. Of particular interest is maintaining the calibration of the RICH system’s performance using real data, by selecting background-free samples of K’s and π’s from D*±→ D0 (→K π) π±, and Λ0 → pπ decays.

• Develop hardware or simulation for future LHCb upgrades, and which also have applications for other heavy flavour experiments. This could include studies of the physics performance, characterisation and design of future hybrid pixel detectors for precise measurement of heavy-flavour-decay vertices. Alternatively a student could work on the novel prototype TORCH detector to provide enhanced low-momentum particle identification, measuring time-of-flights to a precision of 15 ps.

A subset of the LHCb group are also involved with the BESIII experiment. BESIII, located in Beijing, uses electron positron collisions to create a charm hadron factory. Despite the radically different environments of LHCb and BESIII, there is a high level of synergy between them, and the combination of results is expected to lead to significant improvements in precision and sensitivity to new physics. There are opportunities for students to be involved in this exciting new venture as a part of their DPhil activities.

Students would usually be expected to spend a year or more at CERN as well as publishing much of their thesis work in peer-reviewed journals. Depending on the proposed thesis topic, the supervisors may be
Neville Harnew (neville.harnew@physics.ox.ac.uk),
Malcolm John (malcolm.john@physics.ox.ac.uk),
Sneha Malde (sneha.malde@physics.ox.ac.uk) or
Guy Wilkinson (guy.wilkinson@cern.ch).

Further information can be obtained from any of the above people, or from the LHCb-Oxford website https://www2.physics.ox.ac.uk/research/lhcb

T2K

Tokai to Kamioka Neutrino Oscillation Experiment

The Oxford T2K group is eager for new D.Phil students to join. We received our first data in November 2009 and have been taking data in both neutrino and anti-neutrino mode. The intensity of the neutrino beam is still increasing allowing for precision measurements. T2K has found the first hint that CP might not be a conserved symmetry in Neutrino Physics. For information about the group's activities and potential thesis analysis work, please see our home page at http://www2.physics.ox.ac.uk/research/t2k/thesis-topics

For more information, contact Professor Giles Barr (giles.barr@physics.ox.ac.uk), Professor Alfons Weber (alfons.weber@physics.ox.ac.uk) or Professor Dave Wark (dave.wark@physics.ox.ac.uk) or Dr Xianguo Lu (xianguo.lu@physics.ox.ac.uk)

Experiments in preparation:

ATLAS Upgrade

High-Luminosity Large Hadron Collider (HL-LHC)

The High-Luminosity Large Hadron Collider (HL-LHC) project will increase the luminosity of proton-proton collisions by a factor of 10 beyond the LHC’s design value. A more powerful LHC enables the observation of rare processes that occur below the current sensitivity level, extends searches for new physics, and allows precision measurements of the Higgs boson and other particles. The HL-LHC is currently expected to begin operations in the second half of 2026, with a nominal levelled instantaneous luminosity of L=7.5×1034cm2s1 corresponding to an average of roughly 140 inelastic pp collisions each beam-crossing. The machine will deliver an integrated luminosity of 3000/fb to the ATLAS experiment over ten years starting in 2025. This is a factor ten greater than the target of 300/fb to be delivered by 2023.

The ATLAS collaboration must replace many subdetectors to take full advantage of this accelerator upgrade. Oxford and the UK are leading the Inner Tracker Upgrade (ITk) in the production of the barrel strip silicon tracker and the forward pixel tracker for the upgraded ATLAS detector.

Precision Higgs Physics at HL-LHC

Simulation of events in the ITk with a pileup of 140

LZ

The nature of dark matter remains one of the biggest unsolved mysteries in modern science. A leading contender in the hunt for dark matter is the LUX-ZEPLIN experiment, which is the primary focus of the Oxford dark matter group. A 10 tonne liquid xenon time projection chamber will be housed at the Sanford Underground Research Facility in South Dakota, with the aim of directly detecting the interactions of dark matter particles with the xenon target. Due to its size, LZ will reach a sensitivity that will either lead to dark matter discovery or, in the absence of a signal, will eventually be limited by the irreducible neutrino background. For further detail, see http://lz.lbl.gov/ or http://www.sanfordlab.org/.

New students joining in October 2021 will do so at an exciting time with commissioning completing and physics data-taking at an early stage. There will be opportunities to participate in on-site activities as well as offline analysis. LZ is a multi-physics machine, with sensitivity to multiple dark matter paradigms over several orders of mass, and both standard-model and novel neutrino processes. Possible thesis topics could revolve around contributions to these high level analyses, but could also be on the important detailed efforts to understand the detector performance through data quality cuts, simulations and modelling. Lastly, with direct dark matter detection being a growing and increasingly competitive field, there are possibilities to undertake R&D work to inform the design of the next generation detector.

Supervisor: Professor Kimberly Palladino kimberly.palladino@physics.ox.ac.uk Professor Hans Kraus hans.kraus@physics.ox.ac.uk

DUNE

Liquid Argon detectors will play a major role in the future of neutrino physics. These high quality image detectors will allow studying neutrino interactions in great details. They have been chosen for the biggest neutrino project ever constructed (The Deep Underground Neutrino Experiment (DUNE)) and will provide the sensitivity required to study some of the big questions of neutrino physics such as the neutrino mass hierarchy and CP violation. To inform the final DUNE design, the collaboration is building a prototype that will be located at CERN. ProtoDUNE will acquire test-beam data from 2018 providing crucial data sets to understand the response of LAr detectors to different types of particles.

The DUNE group is currently looking to recruit PhD students. Several thesis topics are available within our group to work on DUNE and protoDUNE. The student would be expected to participate in studies to help understanding the physics reach of the future DUNE experiment as well as simulations to help make design decisions. The study topics within DUNE are vast and would allow the student to gain strong experience in programming, data simulation and analysis. In addition, the student would be expected to analyse data from protoDUNE.

For more information, contact Professor Giles Barr (giles.barr@physics.ox.ac.uk) or Professor Alfons Weber (alfons.weber@physics.ox.ac.uk) or Dr Xianguo Lu (xianguo.lu@physics.ox.ac.uk)

SNO+

Neutrino Physics at the SNOLAB facility in Canada

SNO+: Neutrino Physics at the SNOLAB facility in Canada

Some of the most exciting physics to emerge over the last decade has been in the field of neutrino physics. One of the forefront experiments here has been the Sudbury Neutrino Observatory (SNO), based in Canada, which was a recipient of the 2015 Nobel Prize in physics. The SNO group at Oxford have played a leading role in solving the "Solar Neutrino Problem" and clearly demonstrating, for the first time, that neutrinos exists as mixed states which allow them to apparently "oscillate" from one type to another. On the heels of this tremendously successful project, a follow-on experiment, SNO+, is being pursued with a remarkably diverse and interesting range of physics objectives. The main objective of this project is to sensitively search for a very rare process called "neutrinoless double beta decay." An observation of this would both permit a determination of the absolute neutrino masses and would establish that neutrinos act as their own antiparticles, which could have significant consequences for our understanding of the matter/antimatter asymmetry in the universe. This area of study is considered to be of extremely high importance in particle physics and the Oxford group has played a fundamental role in establishing the technique that will be used for this search. In addition, other physics goals include studies of low energy solar neutrinos, oscillations of reactor antineutrinos, searches for non-standard modes of nucleon decay, study of geo-neutrinos generated from within the earth, and to act as an important detector for neutrinos from galactic supernovae. The detector is currently being filled with liquid scintillator and isotope for neutrinoless double beta decay will be introduced in 2019. The incoming PhD student would participate in development, simulation, calibration, operation, analysis and the production of first results.

For further information, contact Professor Steve Biller (steven.biller@physics.ox.ac.uk) or visit the website http://snoplus.phy.queensu.ca/

LSST

The coalescence of a binary neutron star system produces both electromagnetic and gravitational waves (GW). In August 2017, the event designated GW170817 heralded joint observations of both types of radiation from such a coalescence, opening a new window into the physics of neutron stars, neutron-rich nucleosynthesis, and post-merger dynamics. Such multi-messenger detections can also provide the next generation of absolute distance measurements in the universe, leading to independent estimates of the Hubble constant. Over the next 10 years, we expect the LIGO-VIRGO detectors to accumulate several times the current number of GW detections, and therefore efficiently detecting the optical counterpart is essential to maximise science gains. The Large Synoptic Survey Telescope (LSST) will begin observing in 2020, and with its fast, deep and wide survey capabilities will play a critical role in this emerging field quickly to detect optical counterparts to GW events. A student on this experiment would begin by helping to develop an observing strategy for the LSST to accomplish this and other goals concurrently - this project would involve proposing modifications to the existing observing schedule, using sensor characterisation and commissioning data to lay the groundwork for and make the first measurement of the Hubble constant using gravitational wave triggers with the LSST. Potential supervisors: Dr Farrukh Azfar, Professor Ian Shipsey in collaboration with partners in the USA.

In addition, core-collapse supernovae are expected to produce neutrinos and gravitational waves in advance of electromagnetic radiation. As in the case of neutron star mergers, the LSST is positioned to be among the first optical telescopes to take measurements of such rare phenomena early in their lifecycle, and improve their localization for more detailed, spectroscopic, and longer-term follow-up by other telescopes. A student pursuing this project will work with the alert mechanisms of the LSST, gravitational wave detectors (e.g, GraceDB), and neutrino detectors (SNEWS), along with models of supernovae and detector responses in order to improve our ability to peer into the dynamics of these violent and yet highly creative forces in the universe.

Potential supervisors: Dr Jeff Tseng (jeff.tseng@physics.ox.ac.uk)
Dr Farrukh Azfar (farrukh.azfar@physics.ox.ac.uk)

R&D projects and the John Adams Institute

John Adams Institute for Accelerator Science

The John Adams Institute was founded in April 2004 as one of two Institutes of Accelerator Science in the UK. The institute is a joint venture between Oxford University, Royal Holloway, University of London and Imperial College London. The current R&D projects are focused on the area of synergy between laser and plasma physics and accelerators; on research towards novel compact light sources and FELs; on design studies for future colliders and neutrino factories; on development of advanced beam instrumentation and diagnostics; on development of new accelerator techniques for applications in medicine, energy, and other fields of science; and research towards upgrades for existing facilities such as ISIS, Diamond, LHC, and new facilities such as ESS and Future Circular Collider. The institute is developing connections with industry, aiming to render the benefits of accelerator science and technology accessible to society. The Institute also has a vigorous outreach programme. Opportunities in a wide variety of research areas exist, as indicated below.

The sections shown below describe the thesis topics available at JAI in Oxford. For more details about the past projects and about projects available at JAI in RHUL and Imperial, visit this page For further information see this page http://www.adams-institute.ac.uk/training/admissions/ and contact Professor Phil Burrows (philip.burrows@physics.ox.ac.uk).

The Rutherford-Appleton Laboratory may also offer joint RAL-Oxford Studentships in accelerator topics. For further information see this page http://www.stfc.ac.uk/ASTeC/Groups/Intense+Beams+Group/17527.aspx and contact Dr John Thomason (john.thomason@stfc.ac.uk).

Optimization of support structures for future trackers

Future collider experiments will require support structures and services which will use significantly less material than current systems. This can only be achieved with modern engineering techniques using advanced composite materials (e.g. ultra-high modulus carbon fibre, high-thermal conductivity materials), state-of-the art fabrication techniques (e.g. 3d printing) and a high level of integration (e.g. co-curing).

After design the performance of the solutions developed to meet this challenge needs to be verified. This comprises measurements of mechanical stability under various thermal and mechanical loads at the sub-μm level and verification of the thermal performance. Because of the unique requirements for HEP experiments a mix of existing state-of-the-art and to-be-developed measurement techniques are required for this task.

While these R&D activities have a strong connection to mechanical engineering they require a good understanding of topics across many fields of physics (mechanics, thermodynamics, and optics) and are a great opportunity to unleash all the things you suffered through in your undergraduate years to enable future breakthroughs in particle physics.

For more information on these topics contact Georg Viehhauser (georg.viehhauser@physics.ox.ac.uk).

Next-generation high-energy colliders, beam feedback, instrumentation and control

FONT - The FONT group http://www-pnp.physics.ox.ac.uk/~font/ is the international leader in ultra-fast nanosecond timescale beam feedback systems for future high-energy electron-positron colliders. These feedbacks are mandatory for steering and maintaining colliding beams in all currently conceivable linear collider designs. They are also needed in single-pass electron linacs where a high degree of transverse beam stability is required, such as X-ray FELs. The key elements of the feedback are fast, precision Beam Position Monitor signal processing electronics, fast feedback processors, and ultra-fast high-power drive amplifiers. These components are designed, fabricated and bench-tested in Oxford, and subsequently deployed in beamlines for testing with real electron beams of the appropriate charge and time structure.

We work currently mainly at the Accelerator Test Facility in Tsukuba, Japan, and at the CLIC Test Facility (CTF3) at CERN. The group typically visits Japan 4 times per year, for the purpose of testing our novel feedback systems. We are developing a new phase feed-forward correction system at CTF3 and this is an exciting new project for us. Graduate students play a key role in these beam tests, and there are also opportunities to spend time in Japan, at CERN (Geneva) and SLAC (California), as well as to give posters and papers at international conferences.

We are a young and dynamic research team. 20 D. Phil. theses have been completed or are in progress and our graduates have moved on to jobs at CERN, SLAC (USA), Brookhaven (USA), DESY (Germany) and ESS (Sweden).

Thesis supervisor: Professor Philip Burrows (philip.burrows@physics.ox.ac.uk)

Laser-Plasma Accelerators

In a laser wakefield accelerator an intense laser pulse propagating through a plasma excites a trailing plasma wave via the action of the ponderomotive force, which acts to expel electrons from the region of the laser pulse. The longitudinal electric field in this plasma wakefield can be as high as 100 GV / m, more than three orders of magnitude larger than that found in conventional RF accelerators such as those used at CERN. Particles injected into the correct phase of the plasma wave can therefore be accelerated to energies of order 1 GeV in only a few tens of millimetres. Laser-driven plasma accelerators could therefore drive novel, very compact sources of particles and ultrafast radiation.

Theoretical and experimental work on plasma accelerators in Oxford is undertaken by a collaboration of research groups in the sub-departments of Particle Physics and Atomic & Laser Physics. For this reason applications to work in this area should be made to the sub-departments of Atomic & Laser physics AND to Particle Physics.
Our work in this area is undertaken in our new high-power laser lab in Oxford, and at national laser facilities in the UK and elsewhere. We have recently been awarded a £2M, 4-year grant from EPSRC to support our research programme.

Further information on our research can be found on the laser-plasma accelerator group website

We are offering two DPhil projects to start in October 2021, as outlined below.

1. X-ray sources driven in all-optical plasma channels
Conventional electron-beam-driven light sources (i.e. synchrotrons and free-electron lasers) use electron bunches with energies of a few GeV. An Oxford-Berkeley collaboration were the first to generate electron beams with comparable energy from a laser-plasma accelerator. Reaching this energy requires the driving laser pulse, which has an intensity of around 10^18 W / cm^2, to be guided over several centimetres — well beyond the distance over which diffraction occurs.
In the first GeV-scale experiments, the laser pulse was guided in a plasma channel — a gradient refractive index waveguide made from plasma — generated by a capillary discharge. The drawback of this approach is that the discharge structure can be damaged by the driving laser pulse. The Oxford group has recently developed a new type of plasma channel generated by auxiliary laser pulses. Since they are free-standing, these channels are immune to laser damage, and hence they are very promising stages for future multi-GeV plasma accelerators operating at kilohertz pulse repetition rates.
In this project we will investigate further developments of these hydrodynamic optical-field-ionized (HOFI) plasma channels, and their application to the generation of incoherent keV X-rays via the transverse oscillation of the electron bunch in the plasma wakefield.

2. Multi-pulse laser wakefield accelerators
In a laser wakefield plasma accelerator, a short, intense laser pulse is used to drive a longitudinal density wave (a ‘plasma wave’) in a plasma. The electric fields (which constitute a ‘laser wakefield') within this wave are about 1000 times greater than the accelerating fields employed in a conventional, radio-frequency accelerator — and hence laser-plasma accelerators can generate high-energy beams from a very compact accelerator stage. Laser-driven plasma accelerators have already been demonstrated to generated electron beams with energies of several GeV.
To date, most work has been done with single driving pulses. These must have an energy of order 1 J and a duration shorter than the plasma period, which is around 100 fs. These demanding parameters can be generated by Ti:sapphire laser laser systems. However, Ti:sapphire lasers have very low efficiencies (< 0.1%) and (at these pulse energies) are limited to pulse repetition rates below 10 Hz.
Many potential applications of laser-plasma accelerators — such as light sources and future particle colliders — require operation at much higher pulse repetition rates (at least in the kilohertz range) and much higher ‘wall-plug’ efficiencies. New types of laser are becoming available which can meet these requirements, but they generate pulses in the picosecond range, which are too long to drive a plasma wave. If the output pulses of these lasers could be modulated, with a modulation spacing equal to the plasma period, then they could be used to resonantly excite the plasma wave in a plasma accelerator. We have recently shown that this is possible in a proof-of-principle experiment which employed temporally-stretched Ti:sapphire laser pulses.
In this project we will investigate methods for modulating long, high-energy laser pulses to form a train of short, low energy pulses. We will investigate multi-pulse laser wakefield accelerators (MP-LWFA) driven in this way, and will seek to demonstrate electron acceleration in a MP-LWFA for the first time.

For more information, please contact Prof. Simon Hooker (simon.hooker@physics.ox.ac.uk)

The Diamond Light Source and its Upgrade

Provision for Timing Mode Users at Multi-Bend Achromat Synchrotron Light Sources

A step-change in the design of electron storage-rings for synchrotron light sources is currently underway. The latest structures consist of cells of magnets with multiple bending magnets which reduce the electron beam emittance by an order of magnitude and provide a corresponding increase in the source brightness. One consequence of these designs is a substantial reduction in the electron beam lifetime. This is typically compensated for by using harmonic RF cavities to stretch the electron bunches and reduce the particle density. One drawback however is that the emitted x-ray pulses become longer than in previous designs, and the longitudinal dynamics of the circulating electron bunches become more complex. Within this context, the aim of the project is to study how best to meet the needs of timing-mode users, taking the Diamond-II storage ring as an example.
Three potential methods are proposed for study. The first is to use a hybrid filling pattern, in which the ring is filled with one long train of electron bunches to provide the light for the majority of users, and a single electron bunch in a gap for those studying time-dependent phenomenon. The second would be to use ‘pulse-picking by resonant excitation’, in which fast magnets are used to excite vertical oscillations in a single electron bunch. The light from this bunch can then be spatially separated from the remainder for use in timing experiments. The final method would be to use the harmonic cavity to compress the electron bunches rather than stretch them. This would reduce the x-ray pulse length, improving the temporal resolution for users. For each method, particle tracking studies are required to investigate how the electrons react to the applied conditions in order to determine the equilibrium bunch properties and maximum charge before it becomes unstable.
For more information about this project please contact Professor Philip Burrows (philip.burrows@physics.ox.ac.uk) or Dr. Ian Martin (ian.martin@diamond.ac.uk).

Intense Hadron Beams R&D

Collaborative projects between the John Adams Institute and ISIS Neutron and Muon Source may be available to interested applicants. The Intense Beams Group use a number of advanced accelerator physics methods in order to explore the ways to design high current and versatile proton accelerators for scientific, energy, medical or other applications. Existing PhD student projects include applications of the FFA (Fixed-Field Alternating Gradient) type of accelerator and the use of Paul traps to study dynamics in proton accelerators.

For more information please contact Dr Suzie Sheehy (suzie.sheehy@physics.ox.ac.uk) or Dr. Shinji Machida at STFC (shinji.machida@stfc.ac.uk)

The dynamics of charged particle beam in accelerators is a highly interdisciplinary research area crossing electromagnetism, analytical mechanics, and accelerators technology. The application of advanced techniques in nonlinear dynamics opens a number of new applications that extend performance and capabilities of existing machines. The PhD programme focuses on the investigation of beam dynamics in proximity of nonlinear resonances to manipulate the beam phase space distribution and tailor it for new injection and extraction schemes, or novel concepts in advanced radiation sources.

The programme will develop solid theoretical framework as well as advanced computer simulations in nonlinear beam dynamics for leptons. The PhD programme based at CERN however it will have access to experimental shifts at the Diamond Light Source as well as at the European Synchrotron Radiation Facility.

Super-Bright X-rays using Plasma Wigglers

Particle accelerators have made an enormous impact in all fields of natural sciences, from elementary particle physics, to the imaging of proteins and the development of new pharmaceuticals. Modern light sources have advanced many fields by providing extraordinarily bright, short X-ray pulses. Here we want the student to undertake a novel numerical study to characterise and optimise a plasma-based wiggler device.

Previous studies demonstrated that existing third generation light sources can significantly enhance the brightness and photon energy of their X-ray pulses by undulating their beams within plasma wakefields. This study showed that a three order of magnitude increase in X-ray brightness and over an order of magnitude increase in X-ray photon energy was achieved by passing a 3 GeV electron beam through a two-stage plasma insertion device. The production mechanism micro-bunches the electron beam and ensures the pulses are radially polarised on creation. We also demonstrated that the micro-bunched electron beam is itself an effective wakefield driver that can potentially accelerate a witness electron beam up to 6 GeV.

In this project, the student will simulate and help implement experimentally a novel extension to this concept, one where a single electron bunch experience the ponderomotive force of the X-rays and produces SASE radiation, ultimately leading to additional increases in brightness, into the XFEL regime.

For more information please contact Professor Peter Norreys (peter.norreys@physics.ox.ac.uk

MASSIF DPhil Projects

MASSIF is short for Metrology At Selected Science/Industry Interfaces. We work on selected world leading scientific projects from the accelerator, astro and particle physics fields and approach their extremely challenging metrology problems by developing commercially viable instruments that can help to solve them. We do this in close collaboration with both the relevant scientist to find an optimal solution for the science problem and with our industrial partners, Etalon (part of the Hexagon group) and VadaTech to ensure that the instruments we develop and they build achieve the biggest possible impact also in industrial applications.

Among the most challenging metrological problems in science is the alignment and stabilisation of next generation accelerator elements. These often guide or focus or otherwise manipulate nanometre sized beams over many kilometres. The future linear e+-e- colliders ILC, CLIC or FCCee even have to collide such beams after having travelled tens of kilometres requiring extremely precise alignment and nanometre level stabilisation of their elements. Many other accelerator physics project such as the HL-LHC, CEPC or certain medical accelerators face similarly formidable metrology challenges. Oxford Physics will play a leading role in developing metrology instruments that can solve these problems.

The next generation of particle physics detectors for these “Higss factories” will contain extremely low mass tracking detectors, spanning tens of cubic meters, which have to measure charged particle trajectories to micron accuracy. The development and assembly of these structures requires position survey and vibration sensing technology of very high performance which we develop at Oxford Physics.

In astrophysics, many of the next generation of large telescopes such as the GMTO (Giant Magellan Telescope), EELT (European Extremely Large Telescope, KECK, CCAT now called FYST (Fred Young Sub-millimeter Telescope), SRT (Sardina Radio Telescope), LMT (Large Millimetre Telescope) already decided to use the industrial version of Oxfords metrology instruments (Absolute Multiline™) to solve the survey and stabilisation problems of their very large mirrors.

Similarly, many large accelerator centres such as CERN, SLAC, GSI, PSI as well as national institutes of standards, among them (NPL, PTB, le cnam, INRiM), are already using our technology produced under license by Etalon.

A new DPhil student would work with us to understand the impact of metrology and stabilisation problems on the performance of scientific instruments (e.g. how does a future collider luminosity depend on the alignment and stabilisation of its elements), propose solutions to these problems and build and characterise prototype instruments that can deliver the proposed solution. This will involve computer simulations, optical design, DAQ software and finally prototype experiments and their data analysis. During all of this the student is in close collaboration with our industry partners, learning how to make these instruments and their related software and firmware producible, maintainable and commercially viable. The student will also learn about the specific additional requirement for our instruments when they are used in industrial applications where ease of operation, reliability, repairability, traceability, cost and many other factors play larger roles than they do in science applications.

Choosing which scientific problem to focus on is a complex task which will evolve during the first year of the DPhil. This happens by learning about the already existing capabilities of our instruments and the achievable improvements or additions in functionality while comparing these to the general range of problems present in specific science projects.

In any case, the science project ultimately chosen will be one in which Oxford Physics plays a leading role and is well equipped to make important contributions. The largest range of project clearly lies in accelerator physics (JAI) or the particle physics sub-department but collaborations with the astrophysics sub-department are also possible.

AWAKE experiment at CERN

The AWAKE experiment is a unique proton-driven plasma wakefield experiment, aiming to demonstrate acceleration of electrons to high energies (tens of GeV) via accelerating gradients in excess of 1GV/m. JAI/Oxford is leading the design of the electron injection beamline for AWAKE Run 2, as well as developing novel instrumentation systems for measuring co-propagating proton and electron beams. The latter are based on coherent Cherenkov diffraction radiation techniques. There is the opportunity to design and develop prototypes that can be tested with beams at AWAKE, as well as the CLEAR facility at CERN, and to contribute to advancement of AWAKE during Run 2.

To discuss specific project opportunities on AWAKE contact Professor Phil Burrows (philip.burrows@physics.ox.ac.uk)

Advances in particle-beam cancer therapy

Development of Linacs for Challenging Environments

STELLA (Smart Technologies to Extend Lives with Linear Accelerators), is a multidisciplinary effort to produce a comprehensive, linac-based, Radio Therapy system. The international STELLA collaboration, of which the JAI is a founder member, aims to transform the treatment of patients with cancer particularly in LMICs. It is apparent that linear accelerators in LMIC are down more often than those in wealthier countries. This is partly due to environmental factors, but also to lack of trained technical personnel, which increases not only the frequency of failures but the time to resolve them. To improve the recognition of problems and their nature, we aim to develop a system that uses machine learning and artificial intelligence to monitor the log files of a medical linac regularly to diagnose and predict issues, so that a warning system can be implemented. We have an extensive collaborative network in LMIC’s that would allow us eventually to implement such a system, enabling timely interventions.
For more information please contact Professor Manjit Dosanjh (Manjit Dosanjh@cern.ch

Development and exploitation of novel beams for the study of radiobiology

Very High-Energy Electron (VHEE) beams with energies in the range 100–200 MeV offer several advantages over conventional beams. In contrast to photon beams, VHEE beams of small diameter can be scanned and focused to conform to the tumour, thereby producing finer resolution for intensity-modulated treatments. The VHEE beams can be operated at very high dose rates, allowing the generation of the “FLASH effect”. Moreover, compared to proton-beam therapy, VHEE could constitute a superior alternative in terms of compactness, simplicity and ultimately cost-effectiveness. Before VHEE and VHEE-FLASH can be adopted for cancer treatment, it will be necessary to: characterise experimentally the properties of VHEE beams; establish the degree to which the VHEE technique improves penetration, focusing, and scanning; and determine the radiobiological effectiveness of VHEE in vitro and in vivo over a range of beam configurations including the FLASH regime. We propose to study physical beam characteristics and beam dosimetry for feasibility in both VHEE and FLASH irradiation with electrons in collaboration with the CLEAR team at CERN.
For more information please contact Professor Manjit Dosanjh (Manjit Dosanjh@cern.ch)

Modelling Biological and Flash effects in various modalities

The University of Oxford Radiation Oncology institute has developed a mathematical model to predict the biological effects of different modalities, including oxygen and FLASH effects, which depend on pulse height, length and overall dose delivered. This model will be tested by varying and refining the parameters to obtain a clinically usable model to predict effects in treatment. The model works for all charged particles (and by extension also for photons). Preliminary data have been obtained for lower-energy electrons (6MeV), at dose rates commensurate with the FLASH effect. Ideally the model will be tested at CERN. The CERN Linear Electron Accelerator for Research (CLEAR) test facility provides the 50-200MeV and high-charge beam necessary to deliver VHEE and FLASH therapy.
For more information please contact Professor Manjit Dosanjh (Manjit Dosanjh@cern.ch)