K. Pépitone
A5051783436- Particle Accelerators and Free-Electron Lasers
- Particle accelerators and beam dynamics
- Laser-Plasma Interactions and Diagnostics
- Superconducting Materials and Applications
- Gyrotron and Vacuum Electronics Research
- Pulsed Power Technology Applications
- Magnetic confinement fusion research
- Particle Detector Development and Performance
- Laser-induced spectroscopy and plasma
- Atomic and Molecular Physics
- Laser-Matter Interactions and Applications
- Laser Design and Applications
- Radiation Therapy and Dosimetry
- Plasma Diagnostics and Applications
- Magnetic Properties of Alloys
- Electron and X-Ray Spectroscopy Techniques
- Superconductivity in MgB2 and Alloys
- Photocathodes and Microchannel Plates
- Advancements in Photolithography Techniques
- Hemoglobin structure and function
- Ion-surface interactions and analysis
- Advanced Electron Microscopy Techniques and Applications
- High-pressure geophysics and materials
- Terahertz technology and applications
- Particle physics theoretical and experimental studies
Uppsala University
2018-2024
Campbell Collaboration
2022
European Organization for Nuclear Research
2016-2020
Centre d'Études Scientifiques et Techniques d'Aquitaine
2012-2017
Commissariat à l'Énergie Atomique et aux Énergies Alternatives
2012-2017
Czech Technical University in Prague
2016
Centre Lasers Intenses et Applications
2014
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...
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)...
Abstract The energy deposition of ions in dense plasmas is a key process inertial confinement fusion that determines the α-particle heating expected to trigger burn wave hydrogen pellet and resulting high thermonuclear gain. However, measurements ion stopping are scarce mostly restricted velocities where theory agrees with data. Here, we report experimental data at low projectile near Bragg peak, force reaches its maximum. This parameter range features largest theoretical uncertainties...
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.
We show in experiments that a long, underdense, relativistic proton bunch propagating plasma undergoes the oblique instability, which we observe as filamentation. determine threshold value for ratio between transverse size and skin depth instability to occur. At threshold, outcome of experiment alternates filamentation self-modulation (evidenced by longitudinal modulation into microbunches). Time-resolved images density distribution reveal grows an observable level late along bunch,...
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.
Plasma wakefield acceleration is a promising technology to reduce the size of particle accelerators. The use high energy protons drive wakefields in plasma has been demonstrated during Run 1 AWAKE programme at CERN. Protons 400 GeV drove that accelerated electrons 2 under 10 m plasma. collaboration now embarking on with main aims demonstrate stable accelerating gradients 0.5–1 GV/m, preserve emittance electron bunches and develop sources scalable 100s metres beyond. By end 2, scheme should...
Experimental results show that hosing of a long particle bunch in plasma can be induced by wakefields driven short, misaligned preceding bunch. Hosing develops the plane misalignment, self-modulation perpendicular plane, at frequencies close to electron frequency, and are reproducible. Development depends on misalignment direction, its growth extent proton charge. Results have main characteristics theoretical model, relevant other plasma-based accelerators represent first characterization...
Next generation ion therapy magnets both for gantry and accelerator (synchrotron) are under investigation in a recently launched European collaboration that, the frame of H2020 HITRI <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">plus</i> I.FAST programmes, has obtained some funding work packages on superconducting magnets. Design technology will be developed synchrotron -especially- gantry, taking as reference beams 430 MeV/nucleon ions...
In the framework of Future Circular Collider Study a new septum magnet concept ("SuShi") has been developed, and prototype was built at Wigner RCP, tested FREIA facility Uppsala University. The uses canted cosine theta (CCT)-like superconducting passive shield to create zero-field high-field region within its aperture. SuShi is first CCT with both winding layers simultaneously impregnated wax. Details construction will be presented, special emphasis on wax impregnation procedure which deals...
A long, narrow, relativistic charged particle bunch propagating in plasma is subject to the self-modulation (SM) instability. We show that SM of a proton can be seeded by wakefields driven preceding electron bunch. timing reproducibility and control are at level small fraction modulation period. With this seeding method, we independently amplitude seed with charge growth rate Seeding leads larger than instability case.
The AWAKE collaboration prepares a proton driven plasma wakefield acceleration experiment using the SPS beam at CERN. A long bunch extracted from interacts with high power laser and 10 m rubidium vapor cell to create strong wakefields allowing sustained electron acceleration. probe these is created by an accelerator consisting of rf-gun booster structure. This source should provide beams intensities between 0.1 1 nC, lengths 0.3 3 ps emittance order 2 mm mrad. structure accelerate electrons...
A prototype CCT dipole magnet developed by a collaboration between Swedish universities, industry and CERN will be tested at Uppsala University. This 1 m long double-aperture can provide field strength of 3.3 T 85 in 70 mm aperture with an integrated 2.8 Tm. It is intended to replace the current LHC orbit corrector magnets which are reaching end their expected life due radiation load. The new designed handle dose upgrade high-luminosity LHC, deliver about ten times dose. must therefore more...
In the frame of high-luminosity upgrade project for large hadron collider, new twin aperture beam orbit corrector magnets will be installed near recombination dipole (D2). These are 2.2 m long canted cosine theta NbTi dipoles, with two independently powered apertures oriented such that their field vectors perpendicular to each other and direction beams. A 0.5 model magnet in single double configuration a full-length prototype were built tested at CERN. this paper, performance these 1.9 K...
We report the lifetime of intense-laser (2×10^{19} W/cm^{2}) generated relativistic electron pulses in solids by measuring time evolution their Cherenkov emission. Using a picosecond resolution optical Kerr gating technique, we demonstrate that electrons remain as long 50 picoseconds-more than 1000 times longer incident light pulse. Numerical simulations propagation and emitted radiation with Monte Carlo geant4 package reproduce striking experimental findings.
Self-modulation is a beam–plasma instability that useful to drive large-amplitude wakefields with bunches much longer than the plasma skin depth. We present experimental results showing that, when increasing ratio between initial transverse size of bunch and depth, occurs later along bunch, or not at all, over fixed length because amplitude decreases. show cases for which self-modulation does develop, we introduce simple model discussing conditions it would occur after any length. Changing...
For the high luminosity upgrade of CERN large hadron collider, lower β* quadrupole magnets based on advanced Nb <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> Sn conductors will be installed each side ATLAS and compact muon solenoid (CMS) experiment insertion zones. As part technological developments needed to achieve required field gradient 132.6 T/m within a 150-mm aperture, short length model magnets, named MQXFS, are tested both at...
The study of the dynamic response materials induced by electron beams requires precise knowledge beam when it interacts with material. In this framework, CESAR generator is used at CESTA. drives a field emission diode that delivers single-shot intense pulse (≈1 MV, 300 kA, and 100 ns). propagates into gas-filled chamber where focused magnetic onto an aluminum target. analysis characteristics target position allows us to estimate initial conditions required for hydrodynamic simulations....
In the context of CERN's high-luminosity upgrade project (HL-LHC) for Large Hadron Collider (LHC), a new double aperture beam orbit corrector magnets will be installed near recombination dipole (D2). These 2.2 m long NbTi dipoles are built with canted cosine theta (CCT) technique. The two independently powered apertures oriented such that their field vectors perpendicular to each other and direction beams. A full-length prototype was tested at CERN in SM18 test facility. Here we present...
The high-average current electron gun low energy electrons from a thermionic cathode at high intensity is the prototype of drive beam source for Compact Linear Collider project. electromagnetic design was done originally with 2D simulations to minimize emittance high-current operation (of order 8 A) 140 keV. This paper reports on first experimental measurements extraction and transport. For time, 3D tracking simulations, which take into account precisely cathode–grid geometry, have been...
Intense electron beams can be used to study the dynamical response of materials under shocks in order adjust models developed for hydrodynamics simulations. We present this paper a characterization produced field emission diode coupled generator RKA at CEA/CESTA. Cherenkov emission, by beam interacting fused silica disk, was observed fast optical cameras estimate homogeneity. GEANT4 simulations were performed transfer function target and optimize anode foil. First, we chose best cathode...
The AWAKE collaboration prepares a proton driven plasma wakefield acceleration experiment using the SPS beam at CERN. A long bunch extracted from interacts with high power laser and 10 m rubidium vapour cell to create strong wakefields allowing sustained electron acceleration. probe these is supplied by 20 MeV accelerator. accelerator consists of an RF-gun short booster structure. This source should provide beams intensities between 0.1 1 nC, lengths 0.3 3 ps emittance order 2 mm mrad. wide...
Silicon carbide (SiC) composite high-energy varistors have been demonstrated as a viable alternative to linear resistors energy extraction devices during an abrupt loss of superconductivity in magnet, called quench. These typically installed external the cryostat at ambient temperatures, but for some superconducting magnets it may be beneficial mount within vacuum, gaseous environment, or submerged liquid cryogens. Varistors are semiconductors and therefore exhibit temperature-dependent...