scholarly journals Attosecond betatron radiation pulse train

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Vojtěch Horný ◽  
Miroslav Krůs ◽  
Wenchao Yan ◽  
Tünde Fülöp
Keyword(s):  
Laser Pulse ◽  
Electron Bunch ◽  
Spatial Modulation ◽  
Diagnostic Tools ◽  
X Ray ◽  
Particle In Cell ◽  
Potential Applications ◽  
Order Of Magnitude ◽  
Wavelength Radiation ◽  
Plasma Accelerators

Abstract High-intensity X-ray sources are essential diagnostic tools for science, technology and medicine. Such X-ray sources can be produced in laser-plasma accelerators, where electrons emit short-wavelength radiation due to their betatron oscillations in the plasma wake of a laser pulse. Contemporary available betatron radiation X-ray sources can deliver a collimated X-ray pulse of duration on the order of several femtoseconds from a source size of the order of several micrometres. In this paper we demonstrate, through particle-in-cell simulations, that the temporal resolution of such a source can be enhanced by an order of magnitude by a spatial modulation of the emitting relativistic electron bunch. The modulation is achieved by the interaction of the that electron bunch with a co-propagating laser beam which results in the generation of a train of equidistant sub-femtosecond X-ray pulses. The distance between the single pulses of a train is tuned by the wavelength of the modulation laser pulse. The modelled experimental setup is achievable with current technologies. Potential applications include stroboscopic sampling of ultrafast fundamental processes.

scholarly journals Determining the duration of an ultra-intense laser pulse directly in its focus

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Felix Mackenroth ◽  
Amol R. Holkundkar
Keyword(s):  
Laser Pulse ◽  
Electron Bunch ◽  
Particle Dynamics ◽  
Intense Laser ◽  
Intense Laser Pulse ◽  
Static Properties ◽  
Precise Knowledge ◽  
Order Of Magnitude ◽  
Laser Metrology ◽  
Full Intensity

AbstractUltra-intense lasers facilitate studies of matter and particle dynamics at unprecedented electromagnetic field strengths. In order to quantify these studies, precise knowledge of the laser’s spatiotemporal shape is required. Due to material damage, however, conventional metrology devices are inapplicable at highest intensities, limiting laser metrology there to indirect schemes at attenuated intensities. Direct metrology, capable of benchmarking these methods, thus far only provides static properties of short-pulsed lasers with no scheme suggested to extract dynamical laser properties. Most notably, this leaves an ultra-intense laser pulse’s duration in its focus unknown at full intensity. Here we demonstrate how the electromagnetic radiation pattern emitted by an electron bunch with a temporal energy chirp colliding with the laser pulse depends on the laser’s pulse duration. This could eventually facilitate to determine the pulse’s temporal duration directly in its focus at full intensity, in an example case to an accuracy of order 10% for fs-pulses, indicating the possibility of an order-of magnitude estimation of this previously inaccessible parameter.

scholarly journals Coherent short wavelength radiation via picosecond Nd:glass lasers

2002 ◽  
Vol 20 (1) ◽  
pp. 59-65 ◽  
Author(s):  
H. KURODA ◽  
T. OZAKI ◽  
A. ISHIZAWA ◽  
T. KANAI ◽  
K. YAMAMOTO ◽  
...  
Keyword(s):  
Harmonic Generation ◽  
Laser System ◽  
High Harmonic ◽  
X Rays ◽  
X Ray ◽  
Particle In Cell ◽  
Cell Simulation ◽  
Wavelength Radiation ◽  
Hydrodynamic Code ◽  
Scale Length

The generation of coherent soft X rays is studied using a terawatt picosecond Nd:glass laser system. Two different methods are investigated as candidates for efficient generation of such radiation, namely, longitudinally pumped transient collisional excitation nickel-like molybdenum X-ray laser, and high-harmonic generation from solid–vacuum interfaces. In the course of experiments on longitudinally pumped X-ray lasers, unexpected jetlike structures are observed in the visible emission of the molybdenum plasma, extending over a length of several millimeters. An interesting characteristic of this phenomena is that clear jets are observed only for longitudinal pump intensities between 5 × 1014 and 7 × 1014 W/cm2. The effects of a finite scale length density gradient on surface harmonics is also investigated. The efficiency of harmonic generation from near-solid density plasma is found to increase by a factor of 2 to 3 when using prepulses. The scale length of the preplasma is simulated using a one-dimensional hydrodynamic code, and the increase in efficiency is verified to be in accordance with particle-in-cell simulation results.

scholarly journals Numerical simulations of generation of high-energy ion beams driven by a petawatt femtosecond laser

Nukleonika ◽  
2015 ◽  
Vol 60 (2) ◽  
pp. 229-232
Author(s):  
Jarosław Domański ◽  
Jan Badziak ◽  
Sławomir Jabłoński
Keyword(s):  
Laser Pulse ◽  
Mass Density ◽  
Ion Beam ◽  
High Energy ◽  
Particle In Cell ◽  
Ion Energies ◽  
Linearly Polarized ◽  
Order Of Magnitude ◽  
Cell Simulation ◽  
Pulse Polarization

Abstract This contribution presents results of a Particle-in-Cell simulation of ion beam acceleration via the interaction of a petawatt 25 fs laser pulse of high intensity (up to ~1021 W/cm2) with thin hydrocarbon (CH) and erbium hydride (ErH3) targets of equal areal mass density (of 0.6 g/m2). A special attention is paid to the effect that the laser pulse polarization and the material composition of the target have on the maximum ion energies and the number of high energy (>10 MeV) protons. It is shown that both the mean and the maximum ion energies are higher for the linear polarization than for the circular one. A comparison of the maximum proton energies and the total number of protons generated from the CH and ErH3 targets using a linearly polarized beam is presented. For the ErH3 targets the maximum proton energies are higher and they reach 50 MeV for the laser pulse intensity of 1021 W/cm2. The number of protons with energies higher than 10 MeV is an order of magnitude higher for the ErH3 targets than that for the CH targets.

scholarly journals Generation and application of ultrashort X-ray pulses

2001 ◽  
Vol 19 (1) ◽  
pp. 15-22 ◽  
Author(s):  
D. VON DER LINDE ◽  
K. SOKOLOWSKI-TINTEN ◽  
CH. BLOME ◽  
C. DIETRICH ◽  
P. ZHOU ◽  
...  
Keyword(s):  
Laser Pulse ◽  
Time Resolution ◽  
Short Wavelength ◽  
Pulse Width ◽  
Extreme Ultraviolet ◽  
Small Scale ◽  
X Ray ◽  
Laser Pulse Width ◽  
Wavelength Radiation ◽  
Short Wavelength Radiation

Relatively small-scale laser-driven sources of short wavelength radiation covering a range from the extreme ultraviolet to the hard X-ray regime are now available. Because the duration of the X-ray pulses is comparable to, or shorter than the laser pulse width, it is possible to carry out X-ray measurements with picosecond or femtosecond time resolution.

scholarly journals NUMERICAL SIMULATION OF PLATEAU FORMATION BY AN ELECTRON BUNCH ON THE DISTRIBUTION OF AN ACCELERATING WAKEFIELD IN A PLASMA

2020 ◽  
pp. 47-49
Author(s):  
V.I. Maslov ◽  
R.T. Ovsiannikov ◽  
N. Delerue ◽  
V. Kubytskyi ◽  
I.P. Levchuk ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Electron Bunch ◽  
Plasma Accelerator ◽  
The Self ◽  
Promising Candidate ◽  
Particle In Cell ◽  
The Past ◽  
Self Consistent ◽  
Plasma Accelerators

Over the past decade the production of multi-gigaelectrons from laser-driven and electron-bunch-driven plasma accelerators has been successfully demonstrated. However, applications require improvements of accelerated bunch size and its energy spread. One promising candidate to satisfy these requirements is to externally inject an electron bunch into an electron-bunch-driven plasma accelerator. We present studies on the optimization of the self-consistent distribution of an accelerating wakefield of plateau type, which can lead to improvement of final quality of the externally injected and accelerated electron bunch, using simulations with the particle-in-cell code LCODE. We quantified the effect of the injected bunch density on the plateau formation in the blowout regime.

In-Plane Uniaxial Magnetic Anisotropy of Cobalt Doped Y3Fe5O12 Epitaxial Films

1999 ◽  
Vol 603 ◽  
Author(s):  
Darren Dale ◽  
G. Hu ◽  
Vincent Balbarin ◽  
Y. Suzuki
Keyword(s):  
Uniaxial Anisotropy ◽  
Pulsed Laser ◽  
Epitaxial Films ◽  
Laser Deposition ◽  
X Ray Diffraction ◽  
X Ray ◽  
Garnet Films ◽  
Integrated Devices ◽  
Potential Applications ◽  
Order Of Magnitude

AbstractIn an effort to develop a magnetic biasing layer for potential applications in integrated devices, we have grown thin films of Y3Fe5O12 with increased uniaxial anisotropy by doping with varying Co2+, concentration. To compensate for the charge differential between Co2+ and Fe3+, Ge4+ and Ce4+ are substituted for Fe3+ and y3+, respectively. These garnet films, prepared using pulsed laser deposition on (110) oriented Gd3Ga5O12 substrates, exhibit excellent crystallinity as determined from X-ray diffraction and Rutherford backscattering spectroscopy. The addition of Co2+ in Y3Fe5O12 films enhances the in-plane uniaxial anisotropy over an order of magnitude, depending on composition.

Development of a method for multielemental determination in water by EDXRF with radioisotopic source of 238Pu.

2019 ◽  
Vol 7 (2A) ◽  
Author(s):  
Camilo Fuentes Serrano ◽  
Juan Reinaldo Estevez Alvares ◽  
Alfredo Montero Alvarez ◽  
Ivan Pupo Gonzales ◽  
Zahily Herrero Fernandez ◽  
...  
Keyword(s):  
Thin Layer ◽  
Expanded Uncertainty ◽  
Considerable Decrease ◽  
X Ray ◽  
Precipitation Efficiency ◽  
Method Of Determination ◽  
Sensitivity Curves ◽  
Order Of Magnitude ◽  
Metrological Parameters

A method for determination of Cr, Fe, Co, Ni, Cu, Zn, Hg and Pb in waters by Energy Dispersive X Ray Fluorescence (EDXRF) was implemented, using a radioisotopic source of 238Pu. For previous concentration was employed a procedure including a coprecipitation step with ammonium pyrrolidinedithiocarbamate (APDC) as quelant agent, the separation of the phases by filtration, the measurement of filter by EDXRF and quantification by a thin layer absolute method. Sensitivity curves for K and L lines were obtained respectively. The sensitivity for most elements was greater by an order of magnitude in the case of measurement with a source of 238Pu instead of 109Cd, which means a considerable decrease in measurement times. The influence of the concentration in the precipitation efficiency was evaluated for each element. In all cases the recoveries are close to 100%, for this reason it can be affirmed that the method of determination of the studied elements is quantitative. Metrological parameters of the method such as trueness, precision, detection limit and uncertainty were calculated. A procedure to calculate the uncertainty of the method was elaborated; the most significant source of uncertainty for the thin layer EDXRF method is associated with the determination of instrumental sensitivities. The error associated with the determination, expressed as expanded uncertainty (in %), varied from 15.4% for low element concentrations (2.5-5 μg/L) to 5.4% for the higher concentration range (20-25 μg/L).

TEM Studies and Contact Resistance of Au/Ni/Ti/Ta/n-GaN Ohmic Contacts

2003 ◽  
Vol 764 ◽  
Author(s):  
D.N. Zakharov ◽  
Z. Liliental-Weber ◽  
A. Motayed ◽  
S.N. Mohammad
Keyword(s):  
Contact Resistance ◽  
Ohmic Contacts ◽  
High Resolution Electron Microscopy ◽  
X Ray ◽  
Electron Energy Loss Spectrometry ◽  
Resolution Electron ◽  
Order Of Magnitude ◽  
Contact Surfaces ◽  
Electron Energy Loss ◽  
Magnitude Difference

AbstractOhmic Ta/Ti/Ni/Au contacts to n-GaN have been studied using high resolution electron microscopy (HREM), energy dispersive X-ray spectrometry (EDX) and electron energy loss spectrometry (EELS). Two different samples were used: A - annealed at 7500C withcontact resistance 5×10-6 Ω cm2 and B-annealed at 7750C with contact resistance 6×10-5 Ω cm2. Both samples revealed extensive in- and out-diffusion between deposited layers with some consumption ofGaNlayerand formation of TixTa1-xN50 (0<x<25) at the GaN interface. Almost an order of magnitude difference in contact resistances can be attributed to structure and chemical bonding of Ti-O layers formed on the contact surfaces.

Translocations In Space-Time and Simultaneous States of the Universe: Convergent Quantifications and Alternative Solutions from the Principles of Physics for the Challenges of “Time Travel” and “Parallel Universes”

2016 ◽  
pp. 4058-4069
Author(s):  
Michael A Persinger
Keyword(s):  
Single Photon ◽  
Rest Mass ◽  
Space Time ◽  
Hydrogen Line ◽  
Magnetic Forces ◽  
Universal Space ◽  
Potential Applications ◽  
Order Of Magnitude ◽  
Alternative Solutions ◽  
The Universe

                                Translation of four dimensional axes anywhere within the spatial and temporal boundaries of the universe would require quantitative values from convergence between parameters that reflect these limits. The presence of entanglement and volumetric velocities indicates that the initiating energy for displacement and transposition of axes would be within the upper limit of the rest mass of a single photon which is the same order of magnitude as a macroscopic Hamiltonian of the modified Schrödinger wave function. The representative metaphor is that any local 4-D geometry, rather than displaying restricted movement through Minkowskian space, would instead expand to the total universal space-time volume before re-converging into another location where it would be subject to cause-effect. Within this transient context the contributions from the anisotropic features of entropy and the laws of thermodynamics would be minimal.  The central operation of a fundamental unit of 10-20 J, the hydrogen line frequency, and the Bohr orbital time for ground state electrons would be required for the relocalized manifestation. Similar quantified convergence occurs for the ~1012 parallel states within space per Planck’s time which solve for phase-shift increments where Casimir and magnetic forces intersect.  Experimental support for these interpretations and potential applications is considered. The multiple, convergent solutions of basic universal quantities suggest that translations of spatial axes into adjacent spatial states and the transposition of four dimensional configurations any where and any time within the universe may be accessed but would require alternative perspectives and technologies.

scholarly journals A pH-Responsive Foam Formulated with PAA/Gemini 12-2-12 Complexes

2021 ◽  
Vol 5 (3) ◽  
pp. 37
Author(s):  
Hernán Martinelli ◽  
Claudia Domínguez ◽  
Marcos Fernández Leyes ◽  
Sergio Moya ◽  
Hernán Ritacco
Keyword(s):  
Surface Tension ◽  
Dynamic Surface Tension ◽  
Foam Formation ◽  
Ph Responsive ◽  
Dynamic Surface ◽  
X Ray ◽  
Equilibrium Surface Tension ◽  
Potential Applications ◽  
The Stability ◽  
Air Interfaces

In the search for responsive complexes with potential applications in the formulation of smart dispersed systems such as foams, we hypothesized that a pH-responsive system could be formulated with polyacrylic acid (PAA) mixed with a cationic surfactant, Gemini 12-2-12 (G12). We studied PAA-G12 complexes at liquid–air interfaces by equilibrium and dynamic surface tension, surface rheology, and X-ray reflectometry (XRR). We found that complexes adsorb at the interfaces synergistically, lowering the equilibrium surface tension at surfactant concentrations well below the critical micelle concentration (cmc) of the surfactant. We studied the stability of foams formulated with the complexes as a function of pH. The foams respond reversibly to pH changes: at pH 3.5, they are very stable; at pH > 6, the complexes do not form foams at all. The data presented here demonstrate that foam formation and its pH responsiveness are due to interfacial dynamics.

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