scholarly journals Classical Description of Resonant Charge Exchange Involving the Second Flavor of Hydrogen Atoms

Atoms ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 41
Author(s):  
Eugene Oks

We studied the consequences of the existence of the second flavor of hydrogen atoms (SFHA)—the existence proven by atomic experiments and evidenced by astrophysical observations—on the resonant charge exchange. We found analytically that there is indeed an important difference in the corresponding cross-sections for the SFHA compared to the usual hydrogen atoms. This difference could serve as an additional tool for distinguishing between the two kinds of hydrogen atoms in future experiments/observations. We also show that the SFHA does not exhibit any Stark effect—whether in a uniform or a non-uniform electric field—in any order of the perturbation theory.

2017 ◽  
Vol 32 (02n03) ◽  
pp. 1750010 ◽  
Author(s):  
H. L. C. Louzada ◽  
H. Belich

We will study the splitting in the energy spectrum of the hydrogen atom subjected to an uniform electric field (Stark effect) with the Heisenberg algebra deformed leading to the minimum length. We will use the perturbation theory for cases not degenerate (n[Formula: see text]=[Formula: see text]1) and degenerate (n[Formula: see text]=[Formula: see text]2), along with known results of corrections in these levels caused by the minimum length applied purely to the hydrogen atom, so that we may find and estimate the corrections of minimum length applied to the Stark effect.


A theory of the quadratic Stark effect is presented. It is aimed at a description of the hyperfine structure of a free atom in a uniform electric field. A perturbation theory approach is adopted and extensive use is made of effective operators. In spherical tensor form these can be written as the sum of a scalar and a tensor of rank two. Associated scalar and tensor polarizabilities are defined and their properties are discussed. A variety of applications of the theory are given.


1970 ◽  
Vol 48 (3) ◽  
pp. 313-329 ◽  
Author(s):  
Stephen K. Knudson ◽  
Walter R. Thorson

The dominant processes in slow collisions (E < 0.5 keV) of protons and 1s hydrogen atoms are direct elastic scattering, resonant charge exchange, and direct and exchange excitations of H(2p). Differential cross sections have been calculated for all these events by both quantal and classical methods, and characteristics of the resulting Lyman–α (Ly–α) radiation determined.Significant differences from earlier calculations are found for excitation probability, polarization of Ly–α, and the interference oscillations in the charge exchange probability. The phase of the latter is a sensitive function of the interactions causing inelastic scattering. The source of discrepancy with earlier results is the use of the impact parameter approximation (straight-line trajectories); over the range of significant excitation probability, classical path methods using true trajectories give accurate inelastic parameters. Comparison of quantal and classical calculations shows that accurate results for all properties discussed can be obtained by combining classical path calculations of inelastic parameters with semi-classical phase shifts for pure elastic scattering.If polarizations calculated here are used to reinterpret earlier observations of Ly–α emission from 300 eV collisions, the resulting experimental cross sections are not inconsistent with the basic theoretical prediction of equal direct and exchange excitation probabilities.


The total ionization cross section for electrons colliding with metastable 2S atoms has been measured up to 500 eV electron energy by a crossed beam technique. A beam of fast hydrogen atoms, containing about 25% in the 2S state and the rest in the IS ground state, is formed by charge capture onto protons that are passed through a caesium vapour target. Protons emerging from the target are removed from the beam by deflexion in a weak electric field. Atoms formed by capture into long-lived, high quantum states are first ionized in a topographically suitable field and then removed by deflexion in the weak field. The signal arising from electron ionization of the 2S atoms is identified by quenching them in a pulsed electric field. Contributions from other sources of extraneous ionization are eliminated by modulated beam techniques. The cross sections are determined from absolute measurements of the beam fluxes, the geometry of the interaction region and the rate at which 2S atoms are ionized. The results show that as the electron energy is raised, the ionization cross section for 2S atoms rises to a maximum at about 4 times the ionization energy of the 2S state. This maximum, about 10 -15 cm 2 , is 13 times larger than th at of the IS atoms. Comparison with various theoretical determinations indicates th at best agreement is obtained with the Born approximation which includes exchange, but below 100eV the classical Monte Carlo approximation agrees equally well with observations.


Dynamics ◽  
2021 ◽  
Vol 1 (1) ◽  
pp. 1-8
Author(s):  
Eugene Oks

According to the existing paradigm, helium atoms and helium-like ions (hereafter, heliumic systems) in a relatively weak external static electric field do not exhibit the linear Stark effect—in distinction to hydrogen atoms and hydrogen-like ions. In the present paper we consider the classical dynamics of a muonic-electronic heliumic system in Rydberg states–starting from the concept from our previous paper. We show that there are two states of the system where the averaged electric dipole moment is non-zero. Consequently, in these states the heliumic system should exhibit the linear Stark effect even in a vanishingly small electric field, which is a counter-intuitive result. We also demonstrate the possibility of controlling the overall precession of the electronic orbit by an external electric field. In particular, we show the existence of a critical value of the external electric field that would “kill” the precession and make the electronic orbit stationary. This is another counter-intuitive result. We calculate analytically the value of the critical field and show that it is typically smaller or even much smaller than 1 V/cm.


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