A5009827531- Particle Accelerators and Free-Electron Lasers
- Particle accelerators and beam dynamics
- Laser-Plasma Interactions and Diagnostics
- Radiation Detection and Scintillator Technologies
- Particle Detector Development and Performance
- Radiation Therapy and Dosimetry
- Magnetic confinement fusion research
- Particle physics theoretical and experimental studies
- Quantum Chromodynamics and Particle Interactions
- Advanced Radiotherapy Techniques
- Superconducting Materials and Applications
- Atomic and Subatomic Physics Research
- Plasma Diagnostics and Applications
- Radiation Effects in Electronics
- Medical Imaging Techniques and Applications
- Atomic and Molecular Physics
- VLSI and Analog Circuit Testing
- Nuclear Physics and Applications
- Laser-induced spectroscopy and plasma
- Laser-Matter Interactions and Applications
- High-Energy Particle Collisions Research
- Photocathodes and Microchannel Plates
- Formal Methods in Verification
- Analog and Mixed-Signal Circuit Design
- Ionosphere and magnetosphere dynamics
University College London
2013-2024
University of London
2020
Lead City University
2020
Google (United States)
2019
European Organization for Nuclear Research
2016
Imperial College London
2003-2008
RCA (United States)
2005
University of Cambridge
2003
Princeton Microwave Technology (United States)
1976
High energy particle accelerators have been crucial in providing a deeper understanding of fundamental particles and the forces that govern their interactions. In order to increase or reduce size accelerator, new acceleration schemes need be developed. Plasma wakefield acceleration, which electrons plasma are excited, leading strong electric fields, is one such promising novel technique. Pioneering experiments shown an intense laser pulse electron bunch traversing plasma, drives fields 10s...
There is growing interest in the radiotherapy community application of FLASH radiotherapy, wherein dose delivered to entire treatment volume less than a second. Early pre-clinical evidence suggests that these extremely high rates provide significant sparing healthy tissue compared conventional without reducing damage cancerous cells. This has been reflected proton therapy community, with early tests indicating effect also present rate irradiation.In order deliver clinically relevant doses at...
The Advanced Proton Driven Plasma Wakefield Acceleration Experiment (AWAKE) aims at studying plasma wakefield generation and electron acceleration driven by proton bunches. It is a proof-of-principle R&D experiment CERN the world׳s first experiment. AWAKE will be installed in former CNGS facility uses 400 GeV/c beam bunches from SPS. experiments focus on self-modulation instability of long (rms ~12 cm) bunch plasma. These are planned for end 2016. Later, 2017/2018, low energy (~15 MeV)...
New acceleration technology is mandatory for the future elucidation of fundamental particles and their interactions. A promising approach to exploit properties plasmas. Past research has focused on creating large-amplitude plasma waves by injecting an intense laser pulse or electron bunch into plasma. However, maximum energy gain electrons accelerated in a single stage limited driver. Proton bunches are most drivers wakefields accelerate TeV scale stage. An experimental program at CERN—the...
We give direct experimental evidence for the observation of full transverse self-modulation a long, relativistic proton bunch propagating through dense plasma. The exits plasma with periodic density modulation resulting from radial wakefield effects. show that is seeded by ionization front created using an intense laser pulse copropagating bunch. extends over length following seed point. By varying one order magnitude, we frequency scales expected dependence on density, i.e., it equal to...
The seeded self-modulation of a relativistic, charged particle bunch in plasma is shown to grow both along the and plasma, resulting transverse wakefield amplitudes that far exceed initial seed values.
Proton therapy can achieve a highly targeted treatment by utilising the advantageous dosimetric characteristics of Bragg Peak. Protons traversing through material will deposit their maximum energy at Peak ionisation and other interactions, transferring minimal excess dose to surrounding tissue organs. This rate loss is also quantified linear transfer (LET), which indicative radiation quality radiobiological effects. However it challenging physical quantity measure, as characterisation fields...
We propose and use a technique to measure the transverse emittance of laser-wakefield accelerated beam relativistic electrons. The is based on simultaneous measurements electron divergence given by $v_{\perp}/v_{\parallel}$, measured longitudinal spectrum $\gamma_\parallel$ bunch size in bubble $r_{\perp}$. latter obtained via measurement source x-rays emitted accelerating bubble. \textit{normalised} RMS $<0.5$ $\pi$ mm$\:$mrad as an upper limit for spatially gaussian, spectrally...
AWAKE is a proton-driven plasma wakefield acceleration experiment. % We show that the experimental setup briefly described here ready for systematic study of seeded self-modulation 400\,GeV proton bunch in 10\,m-long rubidium with density adjustable from 1 to 10$\times10^{14}$\,cm$^{-3}$. short laser pulse used ionization vapor propagates all way along column, suggesting full vapor. occurs bunch, at time and follows affects bunch.
Abstract Recently, it has been proposed that a mixed helium/carbon beam could be used for online monitoring in carbon ion therapy. Fully stripped, the two species exhibit approximately same mass/charge ratio and hence potentially accelerated simultaneously synchrotron to energy per nucleon. At nucleon, helium ions have about three times range of ions, which allow simultaneous use treatment imaging. In this work, measurements simulations PMMA phantoms as well anthropomorphic irradiated...
Abstract Objective . Small-field dosimetry is an ongoing challenge in radiotherapy quality assurance (QA) especially for radiosurgery systems such as CyberKnife TM The objective of this work to demonstrate the use a plastic scintillator imaged with commercial camera measure output factor system. describes dose on central axis function collimator size, and fundamental part QA integral data used treatment planning Approach A self-contained device consisting solid was build portable Pelicase....
The Front End Test Stand (FETS) under construction at RAL is a demonstrator for front end systems of future high power proton linac. Possible applications include linac upgrade the ISIS spallation neutron source, new sources, accelerator driven sub-critical systems, neutrino factory etc. Designed to deliver 60mA H-minus beam 3MeV with 10% duty factor, FETS consists brightness ion magnetic low energy transport (LEBT), 4-vane 324MHz radio frequency quadrupole, medium (MEBT) containing speed...
The purpose of this study is to characterize the magnitude and depth dose buildup in pencil beam scanning proton therapy.We simulate integrated depth-dose curve realistic beams a water phantom using Geant4 Monte Carlo toolkit. We independently electronic protonic components as function energy from 40 400 MeV, both with without an air gap.At clinical energies, over distance about 1 mm leads reduction at basal layer (0.07 mm) by up 6% compared if no effect were present. Protonic reduces 16%...
The ISIS H− Penning surface plasma source has been developed to produce beam currents up 70mA and pulse lengths 1.5ms at 50Hz. This paper details the investigation into extraction transport in an attempt understand emittance try improve emittance. A scintillator profile measurement technique assess performance of different electrode apertures, geometries, postextraction acceleration configurations. work shows that present extraction, transport, postacceleration system are suboptimal further...
The AWAKE Collaboration has been formed in order to demonstrate proton-driven plasma wakefield acceleration for the first time. This technique could lead future colliders of high energy but a much reduced length when compared proposed linear accelerators. CERN SPS proton beam CNGS facility will be injected into 10 m cell where long bunches modulated significantly shorter micro-bunches. These micro-bunches then initiate strong with peak fields above 1 GV/m that harnessed accelerate bunch...
We study experimentally the longitudinal and transverse wakefields driven by a highly relativistic proton bunch during self-modulation in plasma. show that wakefields' growth amplitude increase with increasing seed as well charge using maximum radius of distribution measured on screen downstream from externally injecting electrons measuring their final energy. Measurements agree trends predicted theory numerical simulations validate our understanding development self-modulation. Experiments...
The commissioning and operation of a particle therapy centre requires an extensive set detectors for measuring various parameters the treatment beam. Among key devices are beam range quality assurance. In this work, novel telescope based on plastic scintillator read out by large-scale CMOS sensor is presented. detector made stack 49 sheets with thickness 2-3 mm active area 100 × mm2, resulting in total physical 124.2 mm. This compact design avoids optical artefacts that common other...
In this article, we briefly summarize the experiments performed during first Run of Advanced Wakefield Experiment, AWAKE, at CERN (European Organization for Nuclear Research). The final goal AWAKE 1 (2013 - 2018) was to demonstrate that \unit[10-20]{MeV} electrons can be accelerated GeV-energies in a plasma wakefield driven by highly-relativistic self-modulated proton bunch. We describe experiment, outline measurement concept and present results. Last, our plans future.
Purpose Recently, there has been increasing interest in the development of scintillator‐based detectors for measurement depth–dose curves therapeutic proton beams (Beaulieu and Beddar [2016], Phys Med Biol ., 61 :R305–R343). These allow single beam parameters such as range or reconstruction full three‐dimensional dose distribution. Thus, scintillation could play an important role quality assurance, online monitoring, imaging. However, light output scintillator a function deposition is...
We study experimentally the effect of linear plasma density gradients on self-modulation a 400\,GeV proton bunch. Results show that positive/negative gradient in/decreases number micro-bunches and relative charge per micro-bunch observed after 10\,m plasma. The measured modulation frequency also in/decreases. With largest positive we observe two frequencies in power spectrum. are consistent with changes wakefields' phase velocity due to adding slow during growth predicted by theory.