Runaway of fast electrons penetrating a thick absorber under the influence of an electric field

1975 ◽  
Vol 46 (4) ◽  
pp. 1824-1826 ◽  
Author(s):  
C. M. Bowden ◽  
J. F. Perkins ◽  
M. T. Raiford ◽  
R. A. Shatas
Keyword(s):  
Electric Field ◽  
Fast Electrons ◽  
Thick Absorber

scholarly journals Ion energy enhancement from TNSA plasmas obtained from advanced targets

2014 ◽  
Vol 32 (3) ◽  
pp. 383-389 ◽  
Author(s):  
L. Torrisi
Keyword(s):  
Electric Field ◽  
Double Layer ◽  
Laser Intensity ◽  
Laser Wavelength ◽  
Rear Side ◽  
Energetic Ions ◽  
Ion Energy ◽  
Fast Electrons ◽  
Surface Reflection ◽  
Laser Absorption

AbstractLaser generated plasmas from target normal sheath acceleration produce energetic ions from the rear side of the target due to the formation of a high directive electric field. Fast electrons are ejected from the rear side of the target and a successive Coulomb explosion is driven by the fast electrons generating a high electric field of double layer. The ion acceleration is mainly controlled by the laser intensity and by the square of the laser wavelength. Literature reports that at intensities of the order of 1018 W/cm2 and at wavelengths of about 1 µm the ion energy is of the order of 5 MeV/nucleon. The use of advanced targets realized with the aim to reduce the surface reflection, to increase the laser absorption coefficient and, with an optimal thickness, to increase the electric field of the double layer, permits to enhance the ion energy acceleration, so that the energy of 5.0 MeV per charge state can be reached at about 1016 W/cm2, as it will be presented and discussed.

scholarly journals Proton acceleration by fast electrons in laser–solid interactions

2002 ◽  
Vol 20 (2) ◽  
pp. 243-253 ◽  
Author(s):  
J.R. DAVIES
Keyword(s):  
Electric Field ◽  
Fast Electron ◽  
Proton Energy ◽  
High Energy ◽  
Dimensional Model ◽  
Proton Acceleration ◽  
Fast Electrons ◽  
One Dimensional ◽  
Long Pulse ◽  
Laser Solid Interactions

The emission of high-energy protons in laser–solid interactions and the theories that have been used to explain it are briefly reviewed. To these theories we add a further possibility: the acceleration of protons inside the target by the electric field generated by fast electrons. This is considered using a simple one-dimensional model. It is found that for relativistic laser intensities and sufficiently long pulse durations, the proton energy gain is typically several times the fast electron temperature. The results are very similar to those obtained for proton acceleration by electron expansion into vacuum.

CONDUCTION MECHANISMS IN IRRADIATED CdSe THIN FILMS

2001 ◽  
Vol 15 (03) ◽  
pp. 297-304
Author(s):  
G. STOENESCU
Keyword(s):  
Thin Films ◽  
Molecular Dynamics ◽  
Electric Field ◽  
Strong Electric Field ◽  
Thin Layers ◽  
Extended Version ◽  
Interaction Potentials ◽  
Fast Electrons ◽  
Potential Barriers ◽  
Conduction Mechanisms

Two conduction regimes defined by different roles of the intercrystalline barriers and crystallites respectively are analyzed for semiconducting polycrystalline vacuum evaporated CdSe thin layers, in strong electric field. We give an interpretation of the effect of fast electrons irradiation on these specific conduction mechanisms. The changing of some microscopic parameters (barrier lengths and potential barriers height) is calculated by fitting the experimental and theoretical I – E characteristics, both for irradiated and unirradiated films. In addition, an extended version of the Antisymmetrized Molecular Dynamics (AMD) method is implemented in order to study clustering aspects for both regimes and to compute the related interaction potentials.

Emission of extraordinary waves from an inhomogeous plasma

1995 ◽  
Vol 54 (3) ◽  
pp. 261-283
Author(s):  
R. Croci
Keyword(s):  
Magnetic Field ◽  
Electric Field ◽  
Analytical Form ◽  
Equilibrium Density ◽  
Fast Electrons ◽  
Plasma Slab ◽  
Model Equations ◽  
The Fourier Transform ◽  
Electron Gyrofrequency ◽  
Theoretical Results

The asymptotic solution of the system of Vlasov and Maxwell equations for a plasma slab with a given current distribution is derived for weak absorption and weak equilibrium density inhomogeneity, but without the usual restriction that the perpendicular wavelengths be larger than the Larmor radii of the thermal particles. The equilibrium magnetic field is homogeneous. No model equations or phenomenological assumptions are introduced, except that the interaction of the components of the electric field parallel and perpendicular to the equilibrium magnetic field (corresponding to the ordinary and extraordinary waves in a homogeneous plasma) has been neglected. The electric field in vacuum is determined by a condition on the analytical form of the Fourier transform of the field that must necessarily also apply to the exact solution. The example presented to illustrate the results considers the emission at the harmonics of the electron gyrofrequency of a population of fast electrons in a plasma with cold ions; the theoretical results are in a very good qualitative agreement with experiment.

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