Modelling properties of hard x-rays generated by the interaction between relativistic electrons and very intense laser beams

2009 ◽  
Vol 42 (2) ◽  
pp. 025601 ◽  
Author(s):  
Alexandru Popa
Keyword(s):  
Intense Laser ◽  
Laser Beams ◽  
Relativistic Electrons ◽  
X Rays

scholarly journals Polarization effects in collisions between very intense laser beams and relativistic electrons

2012 ◽  
Vol 30 (4) ◽  
pp. 591-603 ◽  
Author(s):  
Alexandru Popa
Keyword(s):  
Electron Beams ◽  
Intense Laser ◽  
Laser Beams ◽  
Relativistic Electrons ◽  
X Rays ◽  
Relativistic Electron Beams ◽  
Linearly Polarized ◽  
Promising Source ◽  
Good Agreement ◽  
Scattered Beam

AbstractThe interaction between laser and relativistic electron beams is a promising source of very energetic X rays. We present an accurate model for the collisions between very intense linearly polarized laser beams, corresponding to relativistic parameters of the order of unity or greater, and electrons having energies up to 100 MeV. Our approach uses only one approximation, namely it neglects the radiative corrections. We consider the two cases in which the laser field polarization is either perpendicular or parallel to the plane defined by the directions of propagation of the laser beam and electron beam, and calculate accurately the properties of the σ and π polarized scattered beams. The angle between the directions of the laser and electron beams, denoted by θL, is allowed to have arbitrary values, so that the widely analyzed 180° and 90° geometries, in which the two beams collide, respectively, head on and perpendicularly, are particular cases. We prove that the polarization properties of the scattered beam depend on the angle θL. By varying this angle, the polarization of the scattered beam can be varied between the two limit configurations in which the electromagnetic field of the scattered beam is σ or π polarized with respect to the scattering plane. Our theoretical results are in good agreement with experimental results published in literature. Our model shows that current technologies can be used to produce hard harmonics of the scattered radiations. These harmonics can have relatively high intensities comparable to the intensities of the first harmonics, and energies higher than 1 MeV. Our results lead to the possibility to realize an adjustable photon source with both the energy and polarization of the scattered radiations accurately controlled by the value of the θL angle.

Measurements of parametric X-rays from relativistic electrons in silicon crystals

1987 ◽  
Vol 21 (1-4) ◽  
pp. 49-55 ◽  
Author(s):  
Yu.N. Adishchev ◽  
A.N. Didenko ◽  
V.V. Mun ◽  
G.A. Pleshkov ◽  
A.P. Potylitsin ◽  
...  
Keyword(s):  
Relativistic Electrons ◽  
X Rays ◽  
Silicon Crystals

scholarly journals Self-compression of two co-propagating laser pulse having relativistic nonlinearity in plasma

2017 ◽  
Vol 35 (4) ◽  
pp. 722-729
Author(s):  
S. Kumar ◽  
P. K. Gupta ◽  
R. K. Singh ◽  
R. Uma ◽  
R. P. Sharma
Keyword(s):  
Laser Beam ◽  
Pulse Width ◽  
Pulse Compression ◽  
Group Velocity Dispersion ◽  
Refractive Index Profile ◽  
Intense Laser ◽  
Laser Beams ◽  
Critical Parameters ◽  
Beam Power ◽  
Laser Beam Intensity

AbstractThe study proposes a semi-analytical model for the pulse compression of two co-propagating intense laser beams having Gaussian intensity profile in the temporal domain. The high power laser beams create the relativistic nonlinearity during propagation in plasma, which leads to the modification of the refractive index profile. The co-propagating laser beams get self- compressed by virtue of group velocity dispersion and induced nonlinearity. The induced nonlinearity in the plasma broadens the frequency spectrum of the pulse via self-phase modulation, turn to shorter the pulse duration and enhancement of laser beam intensity. The nonlinear Schrodinger equations were set up for co-propagating laser beams in plasmas and have been solved in Matlab by considering paraxial approximation. The propagation characteristics of both laser beams inside plasma are divided into three regions through the critical divider curve, which has been plotted between pulse width τ01 and laser beam power P01. Based on the preferred value of critical parameters, these regions are oscillatory compression, oscillatory broadening, and steady broadening. In findings, it is observed that the compression of the laser beam depends on the combined intensity of both beams, plasma density, and initial pulse width.

A METHOD FOR PARTIAL DECAPITATION OF CHICKEN EMBRYOS; ITS LIMITATIONS AS A SUBSTITUTE FOR ADENOHYPOPHYSECTOMY – AN EVALUATION OF "EQUIVALENT" METHODS IN AMNIOTES

1975 ◽  
Vol 80 (3_Suppla) ◽  
pp. S3-S28 ◽  
Author(s):  
T. W. Betz
Keyword(s):  
Laser Beams ◽  
X Rays ◽  
Embryo Mortality ◽  
Chicken Embryos ◽  
Quantitative Studies ◽  
Sources Of Variation

ABSTRACT A procedure for partial decapitation, some apparent and possible sources of variation, implications, limitations and validation of the operation as "adenohypophysectomy" are described and considered. Usually 75% of "fertilized" eggs contain embryos eligible for surgery at ~38 hours of incubation and often 90 % of these can be operated upon successfully. The procedure requires 1.5 to 2 minutes per embryo. Mortality is high, but enough partially decapitated embryos can be obtained for quantitative studies even to the onset of hatching. Other apparently less accurate, precise, efficient and/or simple ways to remove adenohypophyseal influence during development in amniote embryos include: electro-cautery or -coagulation, X-rays, laser beams, inhibitors, anti-sera and decapitation. Surgical partial decapitation is a practical device for adenohypophyseal developmental endocrinology of chicken embryos.

scholarly journals Radio and X-ray connection in radio mini-halos: Implications for hadronic models

2020 ◽  
Vol 640 ◽  
pp. A37 ◽  
Author(s):  
A. Ignesti ◽  
G. Brunetti ◽  
M. Gitti ◽  
S. Giacintucci
Keyword(s):  
Magnetic Field ◽  
Large Fraction ◽  
Cosmic Ray ◽  
Physical Parameters ◽  
Model Parameters ◽  
Relativistic Electrons ◽  
X Rays ◽  
X Ray ◽  
Hadronic Model ◽  
Radio Halos

Context. A large fraction of cool-core clusters are known to host diffuse, steep-spectrum radio sources, called radio mini-halos, in their cores. Mini-halos reveal the presence of relativistic particles on scales of hundreds of kiloparsecs, beyond the scales directly influenced by the central active galactic nucleus (AGN), but the nature of the mechanism that produces such a population of radio-emitting, relativistic electrons is still debated. It is also unclear to what extent the AGN plays a role in the formation of mini-halos by providing the seeds of the relativistic population. Aims. In this work we explore the connection between thermal and non-thermal components of the intra-cluster medium in a sample of radio mini-halos and we study the implications within the framework of a hadronic model for the origin of the emitting electrons. Methods. For the first time, we studied the thermal and non-thermal connection by carrying out a point-to-point comparison of the radio and the X-ray surface brightness in a sample of radio mini-halos. We extended the method generally applied to giant radio halos by considering the effects of a grid randomly generated through a Monte Carlo chain. Then we used the radio and X-ray correlation to constrain the physical parameters of a hadronic model and we compared the model predictions with current observations. Results. Contrary to what is generally reported in the literature for giant radio halos, we find that the mini-halos in our sample have super-linear scaling between radio and X-rays, which suggests a peaked distribution of relativistic electrons and magnetic field. We explore the consequences of our findings on models of mini-halos. We use the four mini-halos in the sample that have a roundish brightness distribution to constrain model parameters in the case of a hadronic origin of the mini-halos. Specifically, we focus on a model where cosmic rays are injected by the central AGN and they generate secondaries in the intra-cluster medium, and we assume that the role of turbulent re-acceleration is negligible. This simple model allows us to constrain the AGN cosmic ray luminosity in the range ∼1044−46 erg s−1 and the central magnetic field in the range 10–40 μG. The resulting γ-ray fluxes calculated assuming these model parameters do not violate the upper limits on γ-ray diffuse emission set by the Fermi-LAT telescope. Further studies are now required to explore the consistency of these large magnetic fields with Faraday rotation studies and to study the interplay between the secondary electrons and the intra-cluster medium turbulence.

Generation of cluster-type entangled coherent states using weak nonlinearities

2011 ◽  
Vol 11 (1&2) ◽  
pp. 124-141
Author(s):  
Nguyen B. An ◽  
Kisik Kim ◽  
Jaewan Kim
Keyword(s):  
Coherent States ◽  
Single Photon ◽  
Optical Devices ◽  
Phase Shifters ◽  
Intense Laser ◽  
Laser Beams ◽  
Beam Splitters ◽  
Photo Detectors ◽  
Cluster Type ◽  
Entangled Coherent States

We propose a scheme to generate a recently introduced type of entangled coherent states using realistic weak cross-Kerr nonlinearities and intense laser beams. An intense laser can be filtered to make a faint one to be used for production of a single photon which is necessary in our scheme. The optical devices used are conventional ones such as interferometer, mirrors, beam-splitters, phase-shifters and photo-detectors. We also provide a detailed analysis on the effects of possible imperfections and decoherence showing that our scheme is robust against such effects.

Sign in / Sign up

Export Citation Format

Share Document