Thomas Audet
A5070249661- Laser-Plasma Interactions and Diagnostics
- Laser-induced spectroscopy and plasma
- Particle Accelerators and Free-Electron Lasers
- Laser-Matter Interactions and Applications
- Advanced Surface Polishing Techniques
- Laser Design and Applications
- Pulsed Power Technology Applications
- High-pressure geophysics and materials
- Particle accelerators and beam dynamics
- Particle Detector Development and Performance
- Atomic and Molecular Physics
- Respiratory Support and Mechanisms
- Airway Management and Intubation Techniques
- Ion-surface interactions and analysis
- Magnetic confinement fusion research
- Astrophysical Phenomena and Observations
- Gyrotron and Vacuum Electronics Research
- X-ray Spectroscopy and Fluorescence Analysis
- Gout, Hyperuricemia, Uric Acid
- Astrophysics and Cosmic Phenomena
- Plasma Diagnostics and Applications
- Crystallography and Radiation Phenomena
- Cardiac Arrest and Resuscitation
- Tracheal and airway disorders
- Genital Health and Disease
Queen's University Belfast
2021-2024
Université de Sherbrooke
2024
Université Laval
2023
Université Paris-Sud
2013-2020
Centre National de la Recherche Scientifique
2013-2020
Université Paris-Saclay
2015-2020
Laboratoire de Physique des Gaz et des Plasmas
2013-2019
Lund University
2014
Abstract This report presents the conceptual design of a new European research infrastructure EuPRAXIA. The concept has been established over last four years in unique collaboration 41 laboratories within Horizon 2020 study funded by Union. EuPRAXIA is first project that develops dedicated particle accelerator based on novel plasma acceleration concepts and laser technology. It focuses development electron accelerators underlying technologies, their user communities, exploitation existing...
The Horizon 2020 Project EuPRAXIA ("European Plasma Research Accelerator with eXcellence In Applications") is preparing a conceptual design report of highly compact and cost-effective European facility multi-GeV electron beams using plasma as the acceleration medium. accelerator will be based on laser and/or beam driven approach used for photon science, high-energy physics (HEP) detector tests, other applications such X-ray sources medical imaging or material processing. started in November...
The dynamics of ionization-induced electron injection in high density (∼1.2 × 1019 cm−3) regime laser wakefield acceleration is investigated by analyzing the betatron X-ray emission. In such operation, normalized vector potential exceeds injection-thresholds both ionization-injection and self-injection due to self-focusing. this regime, direct experimental evidence early on-set into plasma wave given mapping emission zone inside plasma. Particle-In-Cell simulations show that injection, its...
Abstract Objective Intubation practices changed during the COVID-19 pandemic to protect healthcare workers from transmission of disease. Our objectives were describe intubation characteristics and outcomes for patients tested SARS CoV-2 infection. We compared between testing COV-2 positive with those negative. Methods conducted a health records review using Canadian Emergency Department Rapid Response Network (CCEDRRN) registry. included consecutive eligible who presented one 47 EDs across...
The stability of beams laser wakefield accelerated electrons in dielectric capillary tubes is experimentally investigated. These are found to be more stable charge and pointing than the corresponding a gas jet. Electron with an average 43 pC standard deviation 14% generated. fluctuations partly correlated pulse energy. scatter electron measured as low 0.8 mrad (rms). High beam improved beams.
Simulations of ionization-induced injection in a laser driven plasma wakefield show that high-quality electron injectors the 50--200 MeV range can be achieved gas cell with tailored density profile. Using PIC code Warp parameters close to existing experimental conditions, we concentration ${\mathrm{N}}_{2}$ hydrogen profile is an efficient parameter tune beam properties through control interplay between loading effects and varying accelerating field For given configuration, moderate...
Ionization-induced electron injection was investigated experimentally by focusing a driving laser pulse with maximum normalized potential of 1.2 at different positions along the plasma density profile inside gas cell, filled mixture composed 99%H2+1%N2. Changing focus position relative to cell entrance controls accelerated bunch properties, such as spectrum width, energy, and charge. Simulations performed using 3D particle-in-cell code WARP realistic give results that are in good agreement...
Sub-micron defects represent a well-known fundamental problem in manufacturing since they can significantly affect performance and lifetime of virtually any high-value component. Positron annihilation spectroscopy is arguably the only established method capable detecting down to sub-nanometer scale but, date, it works for surface studies, with limited resolution. Here, we experimentally numerically show that laser-driven systems overcome these limitations, by generating ultra-short positron...
We report on a study controlled trapping of electrons, by field ionization nitrogen ions, in laser wakefield accelerators variable length gas cells. In addition to ionization-induced the density plateau inside cells, which results wide, but stable, electron energy spectra, regime localized down-ramp at exit is found. The resulting spectra are peaked, with 10% shot-to-shot fluctuations peak energy. Ionization-induced electrons way trap and accelerate large number thus improving efficiency...
In the design of laser plasma electron injectors for multi-stage driven wakefield accelerators, control density is a key element to stabilize acceleration process. A cell with variable parameters used confine gas and tailor profile. The filling process was characterized both experimentally by fluid simulations. Results show good agreement between experiments Simulations were also study effect each on distribution possibility finely
The dynamics of electron acceleration driven by laser wakefield is studied in detail using the particle-in-cell code WARP with objective to generate high-quality bunches narrow energy spread and small emittance, relevant for injector a multistage accelerator. Simulation results, experimentally achievable parameters, show that an $\ensuremath{\sim}11%$ can be obtained ionization-induced injection mechanism mm-scale length plasma. By controlling focusing moderate power tailoring longitudinal...
Abstract The Horizon 2020 project EuPRAXIA (European Plasma Research Accelerator with eXcellence In Applications) is producing a conceptual design report for highly compact and cost-effective European facility multi-GeV electron beams accelerated using plasmas. will be set up as distributed Open Innovation platform two construction sites, one focus on beam-driven plasma acceleration (PWFA) another site laser-driven (LWFA). User areas at both sites provide access to free-electron laser pilot...
The rapid progress that plasma wakefield accelerators are experiencing is now posing the question as to whether they could be included in design of next generation high-energy electron-positron colliders. However, typical structure accelerating wakefields presents challenging complications for positron acceleration. Despite seminal proof-of-principle experiments and theoretical proposals, experimental research plasma-based acceleration positrons currently limited by scarcity beams suitable...
Plasma accelerators present one of the most suitable candidates for development more compact particle acceleration technologies, yet they still lag behind radiofrequency (RF)-based devices when it comes to beam quality, control, stability and power efficiency. The Horizon 2020-funded project EuPRAXIA ("European Research Accelerator with eXcellence In Applications") aims overcome first three these hurdles by developing a conceptual design international user facility based on plasma...
In this work, we experimentally study the effects of nitrogen concentration in laser wakefield acceleration electrons a gas mixture hydrogen and nitrogen. A 15 TW peak power pulse is focused to ionize gas, excite plasma wave accelerate up 230 MeV. We find that at dopant concentrations above 2% total divergence increased high energy are emitted preferentially with an angle ±6 mrad, leading forked spatio-spectral distribution associated direct (DLA). However, can gain more have lower than 4...
The risk of occupational exposure during endotracheal intubation has required the global Emergency Medicine (EM), Anesthesia, and Critical Care communities to institute new COVID- protected guidelines, checklists, protocols. This survey aimed deepen understanding changes in practices across Canada by evaluating pre-COVID-19, early-COVID-19, present-day periods, elucidating facilitators barriers implementation, provider impressions effectiveness safety made.We conducted an electronic,...
In laser-driven wakefield, ionization induced injection is an efficient way to inject electrons in the plasma wave. A detailed study on beam dynamics under influence of loading effects, which can be controlled by concentration nitrogen impurity introduced hydrogen gas was conducted. For a specific value this percentage, final energy high-energy electron bunch becomes nearly independent trapped positions, thus leading small dispersion. We also show that emittance mainly determined process.
Abstract The EuPRAXIA project aims at designing the world's first accelerator based on advanced plasma-wakefield techniques to deliver 5 GeV electron beams that simultaneously have high charge, low emittance and energy spread, which are required for applications by future user communities. Meeting this challenging objective will only be possible through dedicated effort. Many injection/acceleration schemes been explored means of thorough simulations in more than ten European research...
We describe laboratory experiments to generate x-ray photoionized plasmas of relevance accretion-powered sources such as neutron star binaries and quasars, with significant improvements over previous work. A key quantity is referenced, namely the photoionization parameter, defined ξ=4πF/ne where F flux ne electron density. This normally meaningful in an astrophysical steady-state context, but also commonly used literature a figure merit for that are, necessity, time-dependent. demonstrate...