Glory Effect Research Articles

Nuclear glory effect and α- 40Ca scattering

The semiclassical theory of the three turning point scattering problem is applied to analyze α- 40Ca scattering from an optical potential which fits the experimental data very well. Analytic expressions for the barrier and the internal wave scattering amplitudes are used to discuss characteristics of the differential cross section and the excitation function. The uniform glory approximation is shown to give an excellent description of the strong internal wave cross section at backward angles. The connection between the cross section and the optical potential parameters is discussed. The interference of the internal glory wave with the barrier wave is emphasized as a possible source of discriminating the glory effect from a resonance scattering.

Collision Theory Approach to I'+HI→I'H+I Reaction

The impact-parameter method is applied to the hydrogen transfer reaction which has a similarity to resonant charge-transfer processes, due to the fact that mass ratio of H and I is fairly small. The cases for the four combinations (with or without taking account of the momentum transfer; either rectilinear and or curvilinear trajectories) are studied and compared. A (6-12) Lennard-Jones type potential is assumed to determine the curvilinear trajectory of the incident particle. A binding potential between H and I is assumed to be a Morse type. The calculated total cross section shows an undulating structure as a function of the incident velocity, similar to the glory effect, which is discussed in detail. The calculated reaction rate constants at room temperature are about 7×10 12 cc mol -1 sec -1 in the four cases. From our calculation, it appears that the momentum transfer effect is important and that the important contribution to the reaction rate comes from the cases where three atoms are in the collisi...

The giant glory effect in atomic collisions: calculations for Na-I scattering

The giant glory effect discovered in 1973 by Demkov and Los is considered for Na-I scattering. The cut-off Coulomb potential for a certain collision energy produces the ideal giant glory, i.e. total and exact backscattering in the classical approximation. For a real atomic system with its somewhat distorted potential, the scattering is characterized by superposition of rainbow and backscattering glory. The resulting complex interference structure is calculated in the semiclassical approximation.

Electromagnetic scattering from a black hole and the glory effect

Electromagnetic scattering from a black hole and the glory effect

The glory effect in pion-proton scattering

The backward peaks in positive pion-proton elastic scattering are interpreted as due to a glory effect, analogous to the optical glory, which explains the strong enhancement in the backward scattering of light by small water droplets. The mathematical formalism of the model is deduced through a Watson-Sommerfeld transform of the partial-wave expansion of the scattering amplitude.

The giant glory effect in atomic collisions

The effect of total backscattering in elastic collisions from cut-off Coulomb potentials is discussed.

Theoretical studies of inelastic atomic collisions in a two-state model problem

A two-state scattering problem in which two non-crossing Morse curves are coupled by an exponential potential is discussed theoretically in both the diabatic and adiabatic approximations. Inelastic cross sections are estimated by various approximate analytical formulas, which are expressed in terms of the distorted wave matrix elements. The Landau (steepest descent) method is applied to estimate the distorted wave matrix element. The previously proposed separable potential approximation in the adiabatic method is found to be best among others by comparing with the exact numerical results. Transition probability as a function of l (angular momentum of relative motion) is well reproduced by this approximation. A glory effect in the velocity dependence of the cross section is found in the low energy region, and the adiabatic approximation reproduces this undulation phenomenon well.

Study of the Glory Effect for Atomic Collisions in the Hyperthermal Energy Region

The velocity dependence of the total collision cross section for the systems Li–Hg, Na–Hg, K–Hg, Rb–Hg, Cs–Hg, and Na–Cs has been measured for energies between several electron volts and several hundred electron volts. Due to the high angular resolution of the apparatus it was possible to resolve in all cases the glory undulations, which are analyzed in order to determine potential parameters. The influence of the finite angular resolution of the apparatus on the observed glory structure is discussed.

Glory effect in the optical-model analysis of 39K(α, α) 39K elastic scattering

An optical-model analysis of the 39K(α, α) 39K scattering data in the angular range up to 179° and for nine α-particle energies from 22.1 to 28.2 MeV has been performed in order to investigate whether the so-called nuclear glory effect is contained in the optical model. Six four-parameter potentials describing the elastic scattering were found with a depth of the real part ranging from 100 to 300 MeV. Only potentials with a real part deeper than 200 MeV can reproduce the backward scattering. The radius parameters corresponding to these deep potentials are rather small ( r 0 = 1.1 fm. It has been shown in an additional study that partial waves corresponding to the surface region of the target nucleus play an essential role in the backward scattering.