On the effective recombination cross-section and distribution function of free carriers relative to ionized centres

1971 ◽  
Vol 3 (6) ◽  
pp. 427-437 ◽  
Author(s):  
V.V. Antonov-Romanovskii ◽  
Yu.H. Kalnin
Keyword(s):  
Distribution Function ◽  
Cross Section ◽  
Free Carriers

The probe particle scattering cross-section off the many-fermion systems in the impulse approximation

2021 ◽  
Author(s):  
Yahya Younesizadeh ◽  
Fayzollah Younesizadeh
Keyword(s):  
Experimental Data ◽  
Distribution Function ◽  
Spectral Function ◽  
Cross Section ◽  
Response Function ◽  
Momentum Distribution ◽  
Impulse Approximation ◽  
System Response ◽  
Probe Particle ◽  
Momentum Distribution Function

In this work, we study the differential scattering cross-section (DSCS) in the first-order Born approximation. It is not difficult to show that the DSCS can be simplified in terms of the system response function. Also, the system response function has this property to be written in terms of the spectral function and the momentum distribution function in the impulse approximation (IA) scheme. Therefore, the DSCS in the IA scheme can be formulated in terms of the spectral function and the momentum distribution function. On the other hand, the DSCS for an electron off the [Formula: see text] and [Formula: see text] nuclei is calculated in the harmonic oscillator shell model. The obtained results are compared with the experimental data, too. The most important result derived from this study is that the calculated DSCS in terms of the spectral function has a high agreement with the experimental data at the low-energy transfer, while the obtained DSCS in terms of the momentum distribution function does not. Therefore, we conclude that the response of a many-fermion system to a probe particle in IA must be written in terms of the spectral function for getting accurate theoretical results in the field of collision. This is another important result of our study.

scholarly journals Electron Transport in Argon - Hydrogen Mixtures

1980 ◽  
Vol 33 (6) ◽  
pp. 975 ◽  
Author(s):  
GN Haddad ◽  
RW Crompton
Keyword(s):  
Experimental Data ◽  
Distribution Function ◽  
Cross Section ◽  
Transport Coefficients ◽  
Velocity Distribution Function ◽  
Significant Error ◽  
Cross Section Data ◽  
Section Data ◽  
Hydrogen Mixtures ◽  
Legendre Expansion

The transport coefficients υdr and D⊥/μ have been measured in mixtures of 0.5 % and 4 % hydrogen in argon. All measurements were made at 293 K. It is shown that for these mixtures the use of the solution of the Boltzmann equation based on the two-term Legendre expansion of the velocity distribution function introduces no significant error in the analysis of the transport data. All the experimental data have been predicted to within � 3.5 % using previously published cross section data.

DEGENERACY EFFECT ON THE COMPTON SCATTERING POWER

2011 ◽  
Vol 26 (17) ◽  
pp. 1273-1279 ◽  
Author(s):  
M. MAHDAVI ◽  
B. KALEJI
Keyword(s):  
Distribution Function ◽  
Electron Temperature ◽  
Compton Scattering ◽  
Cross Section ◽  
Electron Distribution ◽  
Electron Distribution Function

The Compton scattering is one of the loss processes in fusion media. In this paper the Compton cross-section is calculated in three limits of temperature, non-relativistic, relativistic and ultra-relativistic temperatures. By considering the electron distribution function for all the temperature limits, we found the power of Compton scattering in degenerate media. These results show that the Compton scattering power increases with decreasing electron temperature. So, in degenerate conditions, the Compton loss processes decrease in fusion media.

scholarly journals On the Growth Mechanism of Grains in a Primordial Stage of the Solar Nebula

1974 ◽  
Vol 65 ◽  
pp. 21-35 ◽  
Author(s):  
A. Carusi ◽  
A. Coradini ◽  
C. Federico ◽  
M. Fulchignoni ◽  
G. Magni
Keyword(s):  
Distribution Function ◽  
Cross Section ◽  
Statistical Approach ◽  
Gaseous Medium ◽  
Solar Nebula ◽  
Velocity Distribution Function ◽  
Particle Capture ◽  
Small Particles ◽  
Fluctuation Effect ◽  
Protoplanetary Nebula

Grain accretion processes in a protoplanetary nebula have been studied regarding: (a) the distribution function of grain velocities; (b) electrostatic and electromagnetic mechanisms between grains. The velocity distribution function has been investigated for grains embedded in a turbulent gaseous medium. Results have been obtained for protoplanetary nebula densities ranging from 10−19 to 10−10 g cm−3. Considering interactions between two grains, photoelectrically charged by galactic ultraviolet flux and by charged-particle capture, and solid-solid interactions (dipole fluctuation effect), the authors estimate the physical cross section σ(v) with respect to the geometric one σ0. Then a statistical approach for an assembly of grains gives the accretion or destruction rates for these small particles. Therefore, according to their characteristic velocities, the following processes have been studied: rupture, fusion, vaporization.

Photo-induced Dissociation and Optical Cross Section of Si-H and S-H Complexes in GaAs and AlGaAs

2002 ◽  
Vol 719 ◽  
Author(s):  
M. Barbé ◽  
F. Bailly ◽  
J. Chevallier ◽  
S. Silvestre ◽  
D. Loridant-Bernard ◽  
...  
Keyword(s):  
Carrier Concentration ◽  
Cross Section ◽  
Cross Sections ◽  
Electronic Excitation ◽  
Surface States ◽  
Antibonding State ◽  
Free Carriers ◽  
Bonding State ◽  
Uv Illumination ◽  
Optical Cross Section

AbstractIn GaAs, (Si,H) complexes are efficiently dissociated at 300 K by photons with energies above 3.5 eV. Their optical cross-section is 10-19-10-18 cm2. This dissociation is the result of an electronic excitation of the Si-H bond of the complex from a bonding state to an antibonding state. (Si,H) and (S,H) complexes in AlGaAs alloys are also dissociated under UV illumination with optical cross-sections similar to GaAs. In passivated 2D AlGaAs-GaAs heterostructures, the evolution of the extra sheet carrier concentration at low photon densities presents a loss of free carriers attributed to the filling of surface states. In AlGaAs and in 2D AlGaAs-GaAs heterostructures, the replacement of hydrogen by deuterium in the complexes shows that the (Si,D) and (S,D) complexes are significantly more stable than the (Si,H) and (S,H) complexes as previously found in GaAs:Si,H.

Investigation of the Nonstationary Energy Distribution of an Atomic Collision Cascade

2019 ◽  
pp. 40-49
Author(s):  
A.A. Aleksandrov ◽  
V.A. Akatev ◽  
E.V. Metelkin ◽  
E.Yu. Baryscheva
Keyword(s):  
Distribution Function ◽  
Kinetic Equation ◽  
Energy Distribution ◽  
Cross Section ◽  
Approximate Solutions ◽  
Boltzmann Kinetic Equation ◽  
Interaction Cross Section ◽  
Atomic Collision ◽  
Distinctive Features ◽  
Nonstationary Distribution

In this paper, we derive a nonstationary distribution function describing the energy distribution of the cascade of moving atoms taking into account their multiplication. The function was derived by solving the Boltzmann kinetic equation. The development of the cascade was considered for the materials consisting of atoms of the same type without taking into account the binding energy of atoms at the crystal lattice sites. The scattering of moving atoms is assumed to be elastic and spherically symmetrical in a center-of-inertia system, and the interaction cross-section is assumed to be constant. The use of these assumptions allows us to derive simple analytic formulas for the nonstationary energy distribution function for the cascade and analyze its main distinctive features. The results obtained allow evaluating the accuracy of various approximate solutions.

scholarly journals INTRINSIC CHARM IN PROTON AND J/ψ PHOTOPRODUCTION AT HIGH ENERGIES

1994 ◽  
Vol 09 (12) ◽  
pp. 1083-1092 ◽  
Author(s):  
V. A. SALEEV
Keyword(s):  
Distribution Function ◽  
Quantum Chromodynamics ◽  
Cross Section ◽  
Gluon Fusion ◽  
Dominant Contribution ◽  
Charm Quarks ◽  
High Energies ◽  
Intrinsic Charm ◽  
Nonrelativistic Quark Model ◽  
Hera Collider

J/ψ and open charm photoproduction on charm quarks in a proton via partonic subprocess γc → J/ψc are discussed based on the perturbative theory of quantum chromodynamics and nonrelativistic quark model. It is shown that the value and energy dependence of the cross-section for such process depend remarkably on the choice of charm distribution function in a proton. In the region of small z = EJ/Eγ < 0.2 the contribution of the γc → J/ψc subprocess in the inelastic J/ψ photoproduction spectra is larger than the contribution of the photon-gluon fusion subprocess. At the energy range of HERA collider charm quarks contribution in the total inclusive J/ψ photoproduction cross-section may be equal to 60% of the dominant contribution of photon-gluon fusion mechanism.

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