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monoenergetic-electrons
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Effects of Target Profile on X-Rays Produced by Mono-Energetic Electrons Generated by Femtosecond Lasers
, M.Sc. Thesis Sharif University of Technology ; Sadighi Bonabi, Rasoul (Supervisor)
Abstract
Considering the generation of quasi-monoenergetic electrons with femto-second Lasers, producing X-Rays using these electrons is of interest. Lately, higher efficiencies of x-ray generation have been demonstrated by bombardment of different metal slabs, with quasi-monoenergetic electrons instead of Maxwellian electrons. The goal of this research is to study how changing the geometry of the target will affect efficiency and angular distribution of generated X-rays. The electron source is defined using a theoretical model and experimental data. MCNP4C code has been utilized to simulate the collisions of these electrons with a metal target. Intensity and quality of generated X-Rays are obtained...
A complete accounting of the monoenergetic electron parameters in an ellipsoidal bubble model
, Article Physics of Plasmas ; Volume 17, Issue 3 , 2010 ; 1070664X (ISSN) ; Rahmatollahpur, S ; Sharif University of Technology
2010
Abstract
A reliable analytical expression for the potential of plasma waves with phase velocities near the speed of light is derived. The presented ellipsoid cavity model is more consistent than the previous spherical model and it explains the monoenergetic electron trajectory more accurately especially in the relativistic regime. The electron energy spectrum is also calculated and it is found that the energy distribution ratio of electrons ΔE/E for the ellipsoid model in the here reported condition is about 10%, which is less than half that of the spherical model (25%) and it is in good agreement with the experimentally measured value of 12% under the same condition. The experimental measurements...
Production of Relativistic Mono-Energetic Electron Beams by Using Terawatt and Femtosecond Laser Pulses
, M.Sc. Thesis Sharif University of Technology ; Sadighi Bonabi, Rasoul (Supervisor)
Abstract
In general cases, the generated electron beam with interaction of high intense and ultra short laser with gas plasma targets has large distributed energy spectrum (100%) that is called Quasi-maxwellian energy spectrum. Recently, in some experimental and 3D-PIC simulation results, a narrow band electron energy spectrum has observed that is called Quasi-monoenergetic electron. We approximated that these electrons have Gaussian distribution. High quality quasi-monoenergetic electron beam can focus in small spot. Therefore, there are many applications such as medical applications, crystallography with electron scattering, spectroscopy with soft energy and ultra fast x-ray, photonuclear...
Potential and energy of the monoenergetic electrons in an alternative ellipsoid bubble model
, Article Physical Review A - Atomic, Molecular, and Optical Physics ; Volume 81, Issue 2 , 2010 ; 10502947 (ISSN) ; Rahmatallahpur, S ; Sharif University of Technology
Abstract
The electron acceleration in the bubble regime is considered during the intense laser-plasma interaction. The presented ellipsoid cavity model is more consistent than the previous spherical model, and it explains the monoenergetic electron trajectory more accurately. At the relativistic region, the maximum energy of electrons in the ellipsoid model is about 24% more than the spherical model, and this is confirmed by PIC and the measured experimental results reported here. The electron energy spectrum is also calculated, and it is found that the energy distribution ratio of electrons ΔE/E for the ellipsoid model in the here reported condition is about 11% which is less than the one third that...
New ellipsoid cavity model for high-intensity laser-plasma interaction
, Article Plasma Devices and Operations ; Volume 16, Issue 2 , 2008 , Pages 105-114 ; 10519998 (ISSN) ; Sadighi Bonabi, R ; Afarideh, H ; Sharif University of Technology
2008
Abstract
In this work we present an ellipsoid cavity regime for the production of a bunch of quasi-monoenergetic electrons. The electron output beam is more effective than the periodic plasma wave method or the plasma-channel-guided method. A hyperbola, parabola or ellipsoid path is described for the electron trajectory motion in this model. A dense bunch of relativistic electrons with a quasi-monoenergetic spectrum is self-generated here. The obtained results show a smaller width for the electron energy spectrum in comparison with the previous results. We found that there are optimum conditions to form the ellipsoid cavity. Laser beam properties (such as the spot size, power and pulse duration) and...
Electron trajectory evaluation in laser-plasma interaction for effective output beam
, Article Chinese Physics B ; Volume 19, Issue 6 , 2010 ; 16741056 (ISSN) ; Sadighi Bonabi, R ; Afarideh, H ; Sharif University of Technology
2010
Abstract
Using the ellipsoidal cavity model, the quasi-monoenergetic electron output beam in laser-plasma interaction is described. By the cavity regime the quality of electron beam is improved in comparison with those generated from other methods such as periodic plasma wave field, spheroidal cavity regime and plasma channel guided acceleration. Trajectory of electron motion is described as hyperbolic, parabolic or elliptic paths. We find that the self-generated electron bunch has a smaller energy width and more effective gain in energy spectrum. Initial condition for the ellipsoidal cavity is determined by laser-plasma parameters. The electron trajectory is influenced by its position, energy and...