scholarly journals Laser-Assisted (e, 2e) Collisions in the Symmetric/Asymmetric Coplanar Geometry

Atoms ◽  
2019 ◽  
Vol 7 (2) ◽  
pp. 40
Author(s):  
Abdelkader Makhoute ◽  
Driss Khalil ◽  
Imane Ajana
Keyword(s):  
Cross Section ◽  
Born Approximation ◽  
Laser Field ◽  
Target Atom ◽  
Wave Functions ◽  
Final States ◽  
Triple Differential Cross Section ◽  
Comprehensive Survey ◽  
Direction Of Polarization ◽  
Target Wave

In this review, we present a comprehensive survey of laser-assisted (e, 2e) reactions. The influence of a laser field on the dynamics of (e, 2e) collisions in atomic hydrogen is analyzed in the symmetric and asymmetric coplanar geometries. Particular attention is devoted to the construction of the dressed (laser-modified) target wave functions, in both the initial and final states. The calculation is performed in the framework of Coulomb-Volkov-Born approximation, where the initial and final electrons are described by Volkov wave functions, while the interaction of the incident electron with the target atom is treated in the first and the second Born approximation. The state of the ejected electron is described by a Volkov/Coulomb-Volkov wave function. A detailed account is also given of the techniques we have used to evaluate the scattering amplitudes. The influence of the laser parameters (frequency, intensity, and direction of polarization) on the angular distribution of the ejected electron is discussed, and a number of illustrative examples are given. The structure of the triple differential cross section in the vicinity of resonances is also analyzed.

Rearrangement collisions: two-particle exchange

1964 ◽  
Vol 277 (1369) ◽  
pp. 206-213 ◽  
Keyword(s):  
Energy Dependence ◽  
Cross Section ◽  
Born Approximation ◽  
High Energy ◽  
Electron Exchange ◽  
Final States ◽  
Particle Exchange ◽  
Exchange Cross Section

It is shown that the first Bom approximation for the exchange of two uncorrelated electrons should vanish. A formalism for the T matrix is presented which has this property. The high-energy result for the two-electron exchange cross-section previously calculated in first Born approximation behaves like E -7 . This result is in error due to a lack of orthogonality of initial and final states. When this is corrected the result for uncorrelated electrons has an energy dependence E -11 . The introduction of correlation gives terms behaving like E -10 which cannot be calculated unam biguously.

Bremsstrahlung linear polarization

1989 ◽  
Vol 67 (6) ◽  
pp. 545-561
Author(s):  
W. Del Bianco ◽  
M. Carignan
Keyword(s):  
Differential Cross Section ◽  
Cross Section ◽  
Cross Sections ◽  
Linear Polarization ◽  
Differential Cross ◽  
Born Approximation ◽  
Gamma Ray ◽  
High Energy ◽  
Scattered Electron ◽  
Triple Differential Cross Section

The dependence of the bremsstrahlung perpendicular and parallel triple differential cross sections and the linear polarization on the angles and energies of the incident and scattered electron and of the emitted gamma-ray has been studied in the high-energy small-angle hypothesis. The expression used for the bremsstrahlung triple differential cross section is valid in the Born approximation and for an unscreened Coulomb potential of the nucleus.

CORRELATED NUCLEON EMISSION IN PERIPHERAL RELATIVISTIC HEAVY ION COLLISIONS

1993 ◽  
Vol 08 (13) ◽  
pp. 2287-2296
Author(s):  
L. L. BARZ ◽  
A. F. R. de TOLEDO PIZA
Keyword(s):  
Cross Section ◽  
Born Approximation ◽  
Heavy Ion Collisions ◽  
Short Range ◽  
Heavy Ion ◽  
Relativistic Heavy Ion Collisions ◽  
Final States ◽  
Ion Collisions ◽  
Nucleon Emission ◽  
Short Range Correlations

The effects of short range correlations for two nucleon emission in peripheral relativistic heavy ion collisions are investigated. The cross section is calculated in Born approximation with properly orthogonalized initial and final states.

Resonance charge transfer between H(1s) and H + calculated by means of an approximation based on an expansion in atomic eigenfunctions

1961 ◽  
Vol 264 (1319) ◽  
pp. 547-557 ◽  
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Atomic Hydrogen ◽  
High Energy ◽  
Wave Functions ◽  
Final States ◽  
Energy Limit ◽  
Full Account ◽  
The Cross ◽  
Resonance Charge

An expression for the cross-section describing electron capture by protons in atomic hydrogen is derived from an expansion based on atomic wave functions. Full account is taken of momentum transfer and of the non-orthogonality of the wave functions of the initial and final states by the method due to Bates. The cross-sections have been computed for proton energies from 100 to 1 MeV. In the low energy limit, the results agree with the p.s.s. calculations of Dalgarno & Yadav and in the high energy limit with the calculations of Brinkm an & Kramers.

Second Born approximation to the Bremsstrahlung differential cross-section

1959 ◽  
Vol 253 (1272) ◽  
pp. 103-120 ◽  
Keyword(s):  
Differential Cross Section ◽  
Pair Production ◽  
Cross Section ◽  
Coulomb Potential ◽  
Differential Cross ◽  
Born Approximation ◽  
Yukawa Potential ◽  
Final States ◽  
The Cross ◽  
Cross Section Differential

In this paper we calculate the second Born approximation contribution to the Bremsstrahlung cross-section differential in both the photon and electron angles. This is divergent if a Coulomb potential is considered, but it is found, on following the idea of Dalitz (1951), that all observable quantities turn out to be finite when we perform the calculation for a Yukawa potential and take the limit of zero screening. It is shown that this is true to order Z 3 in the differential cross-section before it is averaged over spins, and the cross-section is calculated explicitly for the case of an unpolarized beam when the final states of polarization are not observed. Further, it is pointed out that the same methods can be applied satisfactorily in the case of pair production.

scholarly journals Schalenmodell-Approximation für drei Körper im Ausgangskanal / Shell-Model Approach for Three Body Final States

1973 ◽  
Vol 28 (2) ◽  
pp. 185-205
Author(s):  
A. Grauel
Keyword(s):  
Energy Distribution ◽  
Shell Model ◽  
Cross Section ◽  
Scattering Theory ◽  
Wave Functions ◽  
Final States ◽  
S Matrix ◽  
Coulomb Effects ◽  
Three Body ◽  
Model Approach

A scattering theory for reactions with three-particle channels above the two-particle threshold is developed. The S-matrix-technique is used for the calculation of the extended S-matrix. Correlated two-particle wave functions in the exit channels are employed to describe the exact two-particle continuum. For the usual shell model only a few partial waves dominate. The cross section depends on the energy-distribution between the two outgoing nucleons. Numerical results are presented for the model (d, 2n)-reaction exciting 0+ -states in O16 without Coulomb-effects. The treatment is restricted to three (2p2h)-states with the particles in the (sd)-shell and holes in the p-shell.

Paarerzeugung durch langsame geladene Teilchen im Coulombschen Feld

1961 ◽  
Vol 16 (2) ◽  
pp. 155-161
Author(s):  
E. Hara
Keyword(s):  
Total Cross Section ◽  
Cross Section ◽  
Correction Factor ◽  
Born Approximation ◽  
Plane Waves ◽  
Coulomb Field ◽  
Pair Creation ◽  
Wave Functions ◽  
Heavy Particles ◽  
Order Of Magnitude

The pair creation cross section for heavy particles in the COULOMB field is calculated using SCBRÖDINGER-COULOMB wave functions for the heavy incident particles and plane waves for the created pair. It is shown that the order of magnitude of the cross section thus obtained is given by the product of the value deduced by HEITLER and NORDHEIM 1 with BORN approximation, and the SOMMERFELD correction factor, which is known for the emission of Bremsstrahlung. The total cross section is computed for proton energies of 8 m c2, 12 m c2 and 16 m c2. It turns out to be smaller than the result of HEITLER and NORDHEIM by several orders of magnitude.

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