A5018015925- Laser-Plasma Interactions and Diagnostics
- Laser-induced spectroscopy and plasma
- Laser-Matter Interactions and Applications
- Magnetic confinement fusion research
- High-pressure geophysics and materials
- Particle Accelerators and Free-Electron Lasers
- Atomic and Molecular Physics
- Particle Detector Development and Performance
- Ion-surface interactions and analysis
- Nuclear Physics and Applications
- Laser Design and Applications
- Chemical and Physical Properties of Materials
- Gyrotron and Vacuum Electronics Research
- Archaeology and Historical Studies
- Dust and Plasma Wave Phenomena
- Electron and X-Ray Spectroscopy Techniques
- Biblical Studies and Interpretation
- Advanced Chemical Physics Studies
- Neutrino Physics Research
- Quantum, superfluid, helium dynamics
- Medieval History and Crusades
- Hispanic-African Historical Relations
- Electrohydrodynamics and Fluid Dynamics
- Advanced X-ray Imaging Techniques
- Medieval Iberian Studies
Heinrich Heine University Düsseldorf
2014-2022
Institute of Applied Physics
2017
RCA (United States)
1983-1986
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 We propose a new approach based on an all-optical set-up for generating relativistic polarized electron beams via vortex Laguerre-Gaussian (LG) laser-driven wakefield acceleration. Using pre-polarized gas target, we find that the topology of resolves depolarization issue injected electrons. In full three-dimensional particle-in-cell simulations, incorporating spin dynamics Thomas-Bargmann Michel Telegdi equation, LG laser preserves polarization by more than 80% while assuring...
Thermally grown SiO2 layers on Si were bombarded with He+, Ar+, and Xe+ ions at energies between 0.5 2 keV subsequently studied by XPS. Chemical shifts of the 2p O 1s peaks not observed as a result sputtering. Apparently, oxide is reduced ion bombardment. However, widths increase dose energy. A steady state peak width was obtained each energy for doses above 2×1017 cm−2. Steady dependence species explained model based mean-projected range. Peak broadening can be an in disorder that results...
The acceleration of polarized electrons and protons in strong laser plasma fields is a very attractive option to obtain beams the GeV range. We investigate feasibility particle without destroying an initial polarization, taking into account all relevant mechanisms that could cause polarization losses, i.e. spin precession described by T-BMT equation, Sokolov-Ternov effect Stern-Gerlach force. Scaling laws for (de-)polarization time caused these effects reveal dominant limiting rotation...
We investigate the precession of electron spins during beam-driven plasma-wakefield acceleration based on density down-ramp injection by means full three-dimensional (3D) particle-in-cell (PIC) simulations. A relativistic beam generated via, e.g., laser wakefield acceleration, serves as driving source. It traverses prepolarized gas target and accelerates polarized electrons via excited wakefield. derive criteria for parameters limitation injected flux to preserve a high degree polarization...
Tin oxide thin films were exposed to an rf excited hydrogen plasma (100 mTorr) for various times. The system was operated in a self-biased mode. X-ray photoelectron spectroscopy analysis of vacuum transferred samples shows that SnO2 is reduced. A self-limiting layer elemental Sn forms on the reduced film thickness ∼10 Å.
We study hollow plasma channels with smooth boundaries for laser-driven electron acceleration in the bubble regime. Contrary to uniform case, laser forms no optical shock and etching at front. This increases effective phase velocity energy gain. The longitudinal field has a plateau that allows mono-energetic acceleration. observe as low 10^{-3} r.m.s. relative witness beam uncertainty each cross-section 0.3% total spread. By varying density profile inside deep channel, fields can be adjusted...
This document provides detailed information on the status of Advanced and Novel Accelerators techniques describes steps that need to be envisaged for their implementation in future accelerators, particular high energy physics applications. It complements overview prepared update European Strategy particle physics, a description field. The scientific priorities community are described each technique acceleration able achieve accelerating gradient GeV~range or above. ALEGRO working group...
A method of generating spin-polarized proton beams from a gas jet by using multipetawatt laser is put forward. With currently available techniques producing prepolarized monatomic gases photodissociated hydrogen halide molecules and petawatt lasers, with energy $\ensuremath{\gtrsim}50$ MeV $\ensuremath{\approx}80%$ polarization are proved to be obtained. Two-stage acceleration spin dynamics protons investigated theoretically means fully self-consistent three-dimensional particle-in-cell...
We introduce a first full analytical bubble and blow-out model for radially inhomogeneous plasma in quasi-static approximation. For both cases we calculate the accelerating focusing fields. In our also assume thin electron layer that surrounds wake field configuration within. Our theory holds arbitrary radial density profiles reduces to known models limit of homogeneous plasma. From previous study hollow channels with smooth boundaries laser-driven acceleration regime know pancake-like laser...
We propose a filter method to generate electron beams of high polarization from bubble and blow-out wakefield accelerators. The mechanism is based on the idea identifying all electron-beam subsets with low filtering them out an X-shaped slit placed immediately behind plasma accelerator. To find these we investigate dependence between initial azimuthal angle spin single electrons during trapping process. This shows that transverse spins preserve their orientation injection if they are...
Article Über die Invarianz der Stabilität bei einem Phasenraum-Homöomorphismus. was published on January 1, 1964 in the journal Journal für reine und angewandte Mathematik (volume 1964, issue 213).
We report on the concept of an innovative source to produce polarized proton/deuteron beams a kinetic energy up several GeV from laser-driven plasma accelerator. Spin effects have been implemented into particle-in-cell (PIC) simulation code VLPL (Virtual Laser Plasma Lab) make theoretical predictions about behavior proton spins in laser-induced plasmas. Simulations spin-polarized targets show that polarization is conserved during acceleration process. For experimental realization, HCl...
Based on the already existing analytical theory of strongly-nonlinear wakefield (which is called "bubble") in transversely inhomogeneous plasmas, we study particular behavior non-loaded (empty) bubbles and with accelerated bunches. We obtain an expression for shape a bubble general case verify it particle-in-cell (PIC) simulations. derive method calculation acceleration efficiency arbitrary The influence flat-top electron bunches studied. It also shown that possible to achieve homogeneous...
An analytical model of a plasma bubble (a wake wave in the strongly nonlinear regime) transversely inhomogeneous is generalised to an arbitrary profile electron sheath at its boundary. Within framework this generalisation we have found potential within and shown that envelope described by second-order equation, similar equation less general theory. We also determined domain parameters which considerably simplified no longer depends on sheath.
Based on a model of plasma wakefield in the strongly nonlinear (bubble) regime, we develop lowest-order perturbation theory for components electromagnetic fields inside and outside bubble using assumption small thickness electron sheath boundary bubble. Unlike previous models, derive simple explicit expressions not only vicinity center bubble, but whole volume (including areas driving or accelerated bunches) as well it. Moreover, apply results to case radially non-uniform and, particular,...
We report on the concept of an innovative laser-driven plasma accelerator for polarized proton (or deuteron) beams with a kinetic energy up to several GeV. In order model motion particle spins in plasmas, these have been implemented as additional degree freedom into Particle-in-Cell simulation code VLPL. For experimental realization, HCl gas-jet target is under construction, where polarization determined Lamb-shift polarimeter. The final experiments, aiming at first observation beam from...
An extended analytical model for particle dynamics in fields of a highly-nonlinear plasma wake field (the bubble or blow out regime) is derived. A recently proposed piecewise (Kostyukov et al., New J. Phys., {\bf 12}, 045009 (2010)) generalized to include time dependent radius and full solution the acceleration direction. Incorporation cavity required simulate trapping properly. On other hand, it shown that previously reported does not reproduce formation mono energetic peak spectrum. The...
Abstract The generation of polarized particle beams still relies on conventional accelerators, which are typically very large in scale and budget. Concepts based laser-driven wakefield acceleration have strongly been promoted during the last decades. Despite many advances understanding fundamental physical phenomena, one largely unexplored issue is how spins influenced by huge magnetic fields plasma and, thus, highly can be produced. realization laser-plasma accelerators for now being...
We propose a new method for analytical self-consistent description of the excitation strongly nonlinear wakefield (a bubble) excited by an electron bunch. This makes it possible to calculate shape bubble and distribution electric field in based only on properties driver, without relying any additional parameters. The results are verified particle-in-cell simulations show good correspondence. A complete solution cylindrical drivers scaling laws other plasma accelerator parameters depending...
Some recent experiments have shown that the beam load in bubble and blow-out is located a volume as small few μm3. Now, we show what kinds of inner structures are possible such high dense electron ensemble. Our analysis starts from first principles model for relativistically corrected mutual interaction phenomenological model. Discussing 2D 3D configurations, that, depending on bunch emittance, might be highly ordered configuration, less but still state, or configuration where each performs...
Available analytical wakefield models for the bubble and blow-out regime of electron-plasma acceleration perfectly describe important features like shape, fields, trapping ratio, achievable energy, energy distribution radial emittance. As we show, wakefields with an extremely small amplitude these fail to accelerating electric field its divergence in rear. Since prominent parameter regimes Trojan horse photocathode injection exhibit this feature, it is great importance work out that fix...