Cross-sections for elastic collisions in cesium gas interactions

Vacuum ◽  
1981 ◽  
Vol 31 (4-5) ◽  
pp. 211-212
Keyword(s):  
Cross Sections ◽  
Elastic Collisions ◽  
Gas Interactions

Cross sections for elastic collisions in cesium–gas interactions

1980 ◽  
Vol 58 (11) ◽  
pp. 1649-1650 ◽  
Author(s):  
E. Bernabeu ◽  
J. M. Alvarez
Keyword(s):  
Total Cross Section ◽  
Cross Section ◽  
Cross Sections ◽  
Noble Gas ◽  
Experimental Results ◽  
Molecular Gas ◽  
Elastic Collisions ◽  
Gas Interactions

The shift and broadening constants for D1, D2 lines of Cs – noble gas and Cs – light molecular gas(H2, N2) systems are reported. The total cross section for elastic collisions is calculated from our experimental results. Some considerations are made on the mixing between 62P1/2 and 62P3/2 for these systems.

Zur biologischen Wirksamkeit elastischer Kernstöße

1965 ◽  
Vol 20 (8) ◽  
pp. 764-772 ◽  
Author(s):  
H. Jung
Keyword(s):  
Energy Loss ◽  
Enzymatic Activity ◽  
Cross Section ◽  
Cross Sections ◽  
Proton Energy ◽  
Nuclear Collision ◽  
Thin Layers ◽  
Elastic Collisions ◽  
Nuclear Collisions ◽  
Sharp Minimum

Extremely thin layers of ribonuclease were irradiated with slow protons and the differential inactivation cross section determined for various proton energies in the range from 0.8 to 60 keV. At higher proton energies the inactivation cross section is not strongly dependent on energy but with decreasing proton energy it decreases rapidly, reaches a sharp minimum at 1.2 keV and increases again at still smaller energies. By comparing the experimentally determined inactivation cross sections with the cross sections for energy loss in elastic nuclear collisions and in ionizations, respectively, elastic collisions were demonstrated to destroy, in fact, the enzymatic activity of ribonuclease. The energy required for an inactivation by nuclear collision is only one fourth of the energy necessary for an inactivation by ionization.

scholarly journals Collisions of Nucleons with Atoms: Calculated Cross Sections and Monte Carlo Simulation

2021 ◽  
Vol 9 ◽  
Author(s):  
Francesc Salvat ◽  
José Manuel Quesada
Keyword(s):  
Monte Carlo ◽  
Cross Sections ◽  
Nuclear Reactions ◽  
Impact Ionization ◽  
Neutron Transport ◽  
Emission Spectra ◽  
Monte Carlo Code ◽  
Dose Distributions ◽  
Elastic Collisions ◽  
Proton Impact

After a summary description of the theory of elastic collisions of nucleons with atoms, we present the calculation of a generic database of differential and integrated cross sections for the simulation of multiple elastic collisions of protons and neutrons with kinetic energies larger than 100 keV. The relativistic plane-wave Born approximation, with binding and Coulomb-deflection corrections, has been used to calculate a database of proton-impact ionization of K-shell and L-, M-, and N-subshells of neutral atoms These databases cover the whole energy range of interest for all the elements in the periodic system, from hydrogen to einsteinium (Z = 1–99); they are provided as part of the penh distribution package. The Monte Carlo code system penh for the simulation of coupled electron-photon-proton transport is extended to account for the effect of the transport of neutrons (released in proton-induced nuclear reactions) in calculations of dose distributions from proton beams. A simplified description of neutron transport, in which neutron-induced nuclear reactions are described as a fractionally absorbing process, is shown to give simulated depth-dose distributions in good agreement with those generated by the Geant4 code. The proton-impact ionization database, combined with the description of atomic relaxation data and electron transport in penelope, allows the simulation of proton-induced x-ray emission spectra from targets with complex geometries.

The elastic scattering of slow positrons by hydrogen atoms

1964 ◽  
Vol 278 (1375) ◽  
pp. 479-489 ◽  
Keyword(s):  
Elastic Scattering ◽  
Hydrogen Atom ◽  
Differential Equations ◽  
Cross Sections ◽  
Hydrogen Atoms ◽  
Elastic Collisions

Cross-sections are calculated for the elastic collisions of slow positrons by hydrogen atom s by the use of an approximation in which virtual positronium production and polarization of the atom by the positron are allowed for, the latter by the method of polarized orbitals. The coupled integro-differential equations involved are solved by electronic computation. Very satisfactory results are obtained as judged by comparison with other methods.

scholarly journals On the slowing down of neutrons in various substances containing hydrogen

1935 ◽  
Vol 150 (871) ◽  
pp. 709-728 ◽  
Keyword(s):  
Present State ◽  
Cross Sections ◽  
Elastic Collisions ◽  
Neutron Bombardment ◽  
Slowing Down ◽  
Series Of Experiments ◽  
The Cross ◽  
The Way

Fermi and his collaborators have recently reported that a very large increase in the yield of the radioactivity induced in certain substances by neutron bombardment can be obtained, when the energy of the neutrons has been reduced by elastic collisions with hydrogen nuclei. In order to determine as far as possible the nature of the processes involved, we have performed a series of experiments, using substances containing various proportions of other elements (which absorb or scatter the neutrons) in addition to hydrogen. At the present state of knowledge it is impossible to give an exact account of the phenomena, since, for example, the way in which the cross-sections for scattering and absorption of neutrons by various elements vary with the velocity of the neutrons is not known, but we believe that these experiments lead to a description which is consistent with all the known facts, as well as being highly plausible, even though we have not been able to exclude the possibility of alternative explanations.

Zur biologischen Wirksamkeit elastischer Kernstöße

1969 ◽  
Vol 24 (3) ◽  
pp. 328-332 ◽  
Author(s):  
Horst Jung ◽  
Klaus Kürzinger
Keyword(s):  
Energy Loss ◽  
Cross Section ◽  
Cross Sections ◽  
Proton Energy ◽  
Thin Layers ◽  
Elastic Collisions ◽  
E Coli ◽  
Nuclear Collisions ◽  
The Cross

Dry infectious DNA of bacteriophage ΦΧ174 was irradiated in extremely thin layers with slow protons and the differential inactivation cross section determined for various proton energies in the range from 0.8 to 50 keV. Above 5 keV the inactivation cross section is independent of proton energy, it reaches a shallow minimum between 1 and 1.5 keV, and increases slightly at still smaller energies. By comparing the experimentally determined inactivation cross sections with the cross sections for energy loss in elastic nuclear collisions and in ionizations, respectively, elastic collisions were demonstrated to destroy the ability of ΦΧ-DNA to give rise to intact bacteriophage in spheroplasts of E. coli K12.

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