Merging beams study of ionization of positive ions by electrons

1972 ◽  
Vol 327 (1570) ◽  
pp. 317-328 ◽  
Keyword(s):  
Experimental Data ◽  
Energy Range ◽  
Cross Sections ◽  
Atomic Nitrogen ◽  
Efficiency Curve ◽  
Entire Energy Range ◽  
Positive Ions ◽  
Entire Energy ◽  
Product Ions ◽  
Scaling Rule

The technique of beam superposition is employed in the experimental study of ionization of He+, N+ and 0+ by electrons. The electron energy range extends up to 300 eV. The primary and product ions are mass selected. Relative cross-sections for ionization are obtained as a function of the laboratory energy of the electrons. The experimental data for He+ and N+ are quite consistent with published values of the absolute cross-sections for these systems. By using Thomson’s classical scaling rule for isoelectronic systems, the cross-sections for ionization of O+ are calculated from those for ionization of atomic nitrogen. These values, when normalized to the relative ionization efficiency curve obtained experimentally here, show close overlap over the entire energy range.

scholarly journals Interpretation of Cosmic Ray Composition: the Pathlength Distribution

1981 ◽  
Vol 94 ◽  
pp. 107-108
Author(s):  
R. J. Protheroe ◽  
J. F. Ormes
Keyword(s):  
Chemical Composition ◽  
Interstellar Medium ◽  
Energy Range ◽  
Cross Sections ◽  
Cosmic Ray ◽  
Forthcoming Paper ◽  
Ionization Loss ◽  
Entire Energy Range ◽  
Entire Energy ◽  
Energy Dependent

The chemical composition of cosmic ray nuclei with 3≤Z≤28 between ~100 MeV/nuc and a few hundred GeV/nuc are compared with a consistent set of propagation calculations. These include the effects of spallation (energy-dependent cross sections are used), escape and ionization loss in the interstellar medium and deceleration in the solar cavity. This has enabled a consistent study of the cosmic ray pathlength distribution to be made over this entire energy range. Details of the propagation calculation are left to a forthcoming paper.

ELASTIC SCATTERING OF 28Si–27Al IN A REALISTIC OPTICAL POTENTIAL

1996 ◽  
Vol 05 (03) ◽  
pp. 533-541 ◽  
Author(s):  
M. RASHDAN
Keyword(s):  
Experimental Data ◽  
Elastic Scattering ◽  
Cross Section ◽  
Cross Sections ◽  
Differential Cross ◽  
Optical Potential ◽  
Realistic Model ◽  
Entire Energy Range ◽  
Entire Energy ◽  
Soft Core Potential

Within a realistic model for the optical potential between nuclei based on the solution of the Bethe-Goldstone equation with the Reid soft-core potential, the differential cross-sections of the 28 Si –27 Al system, recently measured at energies around the Coulomb barrier, are calculated. The experimental data are well-reproduced over the entire energy range without any adjustable parameters to fit the cross-section.

scholarly journals Energy Dependence of Total Cross Sections for Reactions with 4, 6he, 6, 7, 9li Nuclei

KnE Energy ◽  
2018 ◽  
Vol 3 (1) ◽  
pp. 21
Author(s):  
Yu Penionzhkevich ◽  
Yu Sobolev ◽  
V Samarin ◽  
M Naumenko
Keyword(s):  
Experimental Data ◽  
Energy Range ◽  
Numerical Solution ◽  
Energy Dependence ◽  
Cross Sections ◽  
Beam Energy ◽  
Microscopic Analysis ◽  
Time Dependent ◽  
Total Cross Sections ◽  
Good Agreement

The paper presents the results of measurement of the total cross sections for reactions 4,6He + Si and 6,7,9Li + Si in the beam energy range 5−50 A⋅MeV. The enhancements of the total cross sections for reaction 6He + Si compared with reaction 4He + Si, and 9Li + Si compared with reactions 6,7Li + Si have been observed. The performed microscopic analysis of total cross sections for reactions 6He + Si and 9Li + Si based on numerical solution of the time-dependent Schrödinger equation for external neutrons of projectile nuclei 6He and 9Li yielded good agreement with experimental data.

Evaluation of Optical Model Potential Using Neutron Induced Cross Section Reaction for Spherical Uranium-238 Isotope up to 20MeV

2015 ◽  
Vol 59 ◽  
pp. 26-34
Author(s):  
Iman Tarik Al-Alawy ◽  
Ronak Ikram Ali
Keyword(s):  
Experimental Data ◽  
Energy Range ◽  
Cross Section ◽  
Cross Sections ◽  
Optical Model ◽  
Threshold Energy ◽  
Model Potential ◽  
Model Parameters ◽  
Incident Neutron ◽  
Optical Model Potential

The evaluation are based on mainly on the calculations of the nuclear optical model potential and relevant parameters are collected and selected from References Input Parameter Library (RIPL) which is being developed under the international project coordinated by the International Atomic Energy Agency (IAEA). The analyzing of a complete energy range has done starting from threshold energy for each reaction. The cross sections are reproduced in fine steps of incident neutron energy with 0.01MeV intervals with their corresponding errors. The recommended cross sections for available experimental data taken from EXFOR library have been calculated for all the considered neutron induced reactions for U-238 isotopes. The calculated results are analyzed and compared with the experimental data. The optimized optical potential model parameters give a very good agreement with the experimental data over the energy range 0.001-20MeV for neutron induced cross section reactions (n,f), (n,tot), (n,el), (n,inl), (n,2n), (n,3n), and (n,γ) for spherical U-238 target elements.

scholarly journals Statistical model calculations of the 7Li +11 Β reaction

2019 ◽  
Vol 10 ◽  
pp. 165
Author(s):  
C. Tsabaris ◽  
C. T. Papadopoulos ◽  
R. Vlastou ◽  
A. A. Pakou ◽  
P. A. Assimakopoulos ◽  
...  
Keyword(s):  
Experimental Data ◽  
Statistical Model ◽  
Energy Range ◽  
Cross Section ◽  
Compound Nucleus ◽  
Cross Sections ◽  
Coulomb Barrier ◽  
Reaction Channel ◽  
Model Calculations ◽  
The Individual

The 7Li + 11 Β reaction has been studied in the energy range from a little below to about three times the Coulomb barrier by measuring the cross section of the 7- ray transitions in the residual nuclei produced. Statistical compound nucleus calculations have been performed in order to interpret the experimental data as well as to extract cross sections of the individual exit channels. The statistical compound nucleus theory can reproduce rather well the absolute j - ray and the various reaction channel excitation functions.

scholarly journals Optical Model Potential Using CINDA Library for Neutron Induced Cross Section Reactions for Spherical Uranium-235,238 Isotopes

2015 ◽  
Vol 60 ◽  
pp. 66-73
Author(s):  
Iman Tarik Al-Alawy ◽  
Ronak Ikram Ali
Keyword(s):  
Experimental Data ◽  
Energy Range ◽  
Cross Section ◽  
Cross Sections ◽  
Optical Model ◽  
Threshold Energy ◽  
Model Potential ◽  
Model Parameters ◽  
Incident Neutron ◽  
Optical Model Potential

The calculation are based mainly on the nuclear optical model potential and relevant parameters are collected and selected from References Input Parameter Library (RIPL) which is being developed under the international project coordinated by the International Atomic Energy Agency (IAEA). The analyzing of a complete energy range has done starting from threshold energy for each reaction. The cross sections are reproduced in fine steps of incident neutron energy with 0.01MeV intervals with their corresponding errors. The recommended cross sections for available experimental data taken from CINDA library have been calculated for all the considered neutron induced reactions for spherical U-235 and U-238 isotopes. The calculated results are analyzed and compared with the experimental data. The optimized optical potential model parameters give a very good agreement with the experimental data over the energy range 0.001-20MeV for neutron induced cross section reactions (n,f), (n,tot), (n,el), (n,inl), (n,2n), (n,3n), and (n,γ) for spherical U-235 and U-238 target elements.

Modified Heisenberg's Approach for the Mean Charged Hadron Multiplicity in High Energy Collisions

1978 ◽  
Vol 33 (4) ◽  
pp. 493-497
Author(s):  
D. C. Ghosh ◽  
I. K. Daftari ◽  
D. K. Bhattacharjee ◽  
S. C. Naha ◽  
A. Roy Chowdhury ◽  
...  
Keyword(s):  
Energy Range ◽  
High Energy ◽  
Charged Hadron ◽  
Entire Energy Range ◽  
Hadron Multiplicity ◽  
Entire Energy ◽  
High Energy Collisions ◽  
The Mean ◽  
Hadronic Collisions ◽  
Remarkable Agreement

The semiempirical formulation of Ghosh et al. for the energy dependence of multiplicity in hadronic collisions has been applied to account for the experimental multiplicity data of π±p and K±p collisions. A remarkable agreement has been found over the entire energy range.

Positron–Helium Scattering Cross Sections and Phase Shifts below 19 eV

1973 ◽  
Vol 51 (14) ◽  
pp. 1565-1572 ◽  
Author(s):  
B. Jaduszliwer ◽  
D. A. L. Paul
Keyword(s):  
Energy Range ◽  
Cross Section ◽  
Cross Sections ◽  
Phase Shifts ◽  
S Wave ◽  
Wave Phase ◽  
Entire Energy Range ◽  
Nice Agreement ◽  
Scattering Cross Sections ◽  
D Wave

The total cross sections for elastic scattering of positrons in the energy range from 4 to 19 eV have been measured by the method of transmission. By varying a magnetic field applied along the axis of the scattering chamber the transmitted fraction of the beam is altered, from which individual phase shifts can be extracted. s-, p-, and d-wave phase shifts are given over the entire energy range. The s-wave phase shifts are in agreement with values published by Drachman in 1968, while the p- and d-wave phase shifts are intermediate between values calculated by the same author in 1966 and 1971. The experimental results agree with those of Costello et al., and marginally with our own 1972 results, but are significantly different from those of Canter et al. We compute that the Ramsauer minimum in the diffusion cross section must be 0.04πa02 at 1.6 eV while the minimum in the total cross section is 0.11πa02 at 2.1 eV. The shoulder breadth observed in annihilation experiments is in nice agreement with what one would predict from our phase shifts.

Electron Impact Ionization Cross Sections of N2 and O2

1975 ◽  
Vol 53 (11) ◽  
pp. 1044-1046 ◽  
Author(s):  
Suresh Chandra ◽  
Udit Narain
Keyword(s):  
Experimental Data ◽  
Energy Range ◽  
Electron Impact ◽  
Cross Sections ◽  
Impact Ionization ◽  
Electron Impact Ionization ◽  
Ionization Cross ◽  
Ionization Cross Sections ◽  
Good Agreement

The ionization cross sections of N2 and O2 have been calculated in the energy range from threshold to 20 keV using a modified approach. The results are in good agreement with the available experimental data.

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