Measurements of total collision cross section for dimers of simple atoms and molecules in the glory- and transition region

1976 ◽  
Vol 40 (2) ◽  
pp. 336-338 ◽  
Author(s):  
A. van Deursen ◽  
J. Reuss
Keyword(s):  
Transition Region ◽  
Cross Section ◽  
Collision Cross Section ◽  
Atoms And Molecules ◽  
Total Collision

scholarly journals The scattering of high-energy neutrons by protons and the law of interaction between nucleons

1949 ◽  
Vol 197 (1051) ◽  
pp. 505-523 ◽  
Keyword(s):  
Angular Distribution ◽  
Cross Section ◽  
Interaction Potential ◽  
Yukawa Potential ◽  
Collision Cross Section ◽  
High Energy ◽  
Radial Variation ◽  
Potential Shape ◽  
Total Collision ◽  
Exchange Properties

Calculations have been carried out of the angular distribution and total collision crosssection to be expected in the case of the scattering of neutrons of energy in the range 83 to 250 MeV by protons. Bom’s approximation has been used in these calculations, and a large variety of possible shapes and ranges for the radial variation of the interaction potential have been investigated. For each case the radial variation of the central and non-central parts of the interaction was taken to be the same. The conditions for the validity of this approximation are discussed. Although only fair at the lower end of the energy range studied it should give reasonable results at the upper end of the range, especially in the case of potentials other than the spherical well. The exchange properties of the interaction should be capable of deduction from the general shape of the angular distribution of the scattering curves. It is more difficult to obtain evidence about the exact form of the radial variation of the interaction potential from the angular distribution curves because, for any given potential shape, a wide variety of different predicted angular distributions are obtained by varying the range of the interaction. Potentials of the exponential and Yukawa type, however, show a greater concentration of the scattering into angles near 0 and 180° than is the case for a spherical well interaction. The total collision cross-section depends quite markedly both on the exchange properties and radial variation of the interaction. Closest agreement with the measurements of total cross-section for 90 MeV neutrons are given for a symmetrical interaction with a radial variation in the form of a Yukawa potential of range 1*18 x 10~13 cm., although this interaction predicts too large a value for the ratio of the differential cross-section at 180° to that at 90°.

Nonthermal effects on the elastic electron–atom collision in generalized Lorentzian semiclassical plasmas: Lorentzian renormalization shielding

2015 ◽  
Vol 81 (2) ◽  
Author(s):  
Woo-Pyo Hong ◽  
Young-Dae Jung
Keyword(s):  
Phase Shift ◽  
Cross Section ◽  
Collision Cross Section ◽  
Effective Interaction ◽  
Elastic Electron ◽  
Electron Atom ◽  
Energy Impact ◽  
Scattering Phase ◽  
Total Collision ◽  
Atom Collision

The Lorentzian renormalization plasma shielding effects on the elastic electron–atom collision are investigated in generalized Lorentzian semiclassical plasmas. The eikonal analysis and the effective interaction potential are employed to obtain the eikonal scattering phase shift, differential eikonal collision cross section, and total eikonal collision cross section as functions of the collision energy, impact parameter, nonthermal renormalization parameter, and spectral index of the Lorentzian plasma. It is found that the influence of Lorentzian renormalization shielding suppresses the eikonal scattering phase shift and, however, enhances the eikonal collision cross section in Lorentzian semiclassical plasmas. Additionally, the energy dependence on the total collision cross section in nonthermal plasmas is found to be more significant than that in thermal plasmas.

scholarly journals Orientational anisotropy in the total collision cross section of state selected no molecules

Physica ◽  
1973 ◽  
Vol 66 (1) ◽  
pp. 211-216 ◽  
Author(s):  
S. Stolte ◽  
J. Reuss ◽  
H.L. Schwartz
Keyword(s):  
Cross Section ◽  
Collision Cross Section ◽  
Total Collision

Glory structure in the anisotropy of the total collision cross section

1973 ◽  
Vol 2 (1) ◽  
pp. 1-05 ◽  
Author(s):  
H.L. Schwartz ◽  
S. Stolte ◽  
J. Reuss
Keyword(s):  
Cross Section ◽  
Collision Cross Section ◽  
Total Collision

Collisions and reactions of ultracold molecules

2004 ◽  
Vol 82 (6) ◽  
pp. 709-712 ◽  
Author(s):  
William C Stwalley
Keyword(s):  
High Temperature ◽  
Experimental Observation ◽  
Cross Section ◽  
Collision Cross Section ◽  
Scattering Length ◽  
Collision Dynamics ◽  
Ultracold Molecules ◽  
Atoms And Molecules ◽  
Reactive Behavior ◽  
Ultracold Collision

It is argued that collision dynamics of atoms and molecules at ultracold temperatures (below 1 mK) are not readily predictable from knowledge of collision dynamics above 100 K. In the case of elastic collisions, it is well known that the collision cross section is constant as T → 0 K but mass and symmetry effects are dramatic. The cases of inelastic and reactive collisions are less studied, but a T–1/2 dependence of the cross section as T → 0 K is expected. It seems that extrapolations of high-temperature inelastic and reactive behavior normally greatly underestimate ultracold-temperature rates. The prospects for experimental observation of ultracold collision dynamics are rapidly improving.Key words: ultracold molecules, collisions, reactions, hydrogen, scattering length.

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