scholarly journals Analytical Results for the Three-Body Radiative Attachment Rate Coefficient, with Application to the Positive Antihydrogen Ion H+

Atoms ◽  
2020 ◽  
Vol 8 (2) ◽  
pp. 13
Author(s):  
Jack C. Straton
Keyword(s):  
Rate Coefficient ◽  
Gravitational Interaction ◽  
Analytic Form ◽  
Intermediate Stage ◽  
Spectroscopic Studies ◽  
Hydrogen Ion ◽  
Attachment Rate ◽  
Explicitly Correlated ◽  
Three Body ◽  
Potential Use

To overcome the numerical difficulties inherent in the Maxwell–Boltzmann integral of the velocity-weighted cross section that gives the radiative attachment rate coefficient α R A for producing the negative hydrogen ion H − or its antimatter equivalent, the positive antihydrogen ion H ¯ + , we found the analytic form for this integral. This procedure is useful for temperatures below 700 K, the region for which the production of H ¯ + has potential use as an intermediate stage in the cooling of antihydrogen to ultra-cold (sub-mK) temperatures for spectroscopic studies and probing the gravitational interaction of the anti-atom. Our results, utilizing a 50-term explicitly correlated exponential wave function, confirm our prior numerical results.

scholarly journals Diffusion, Attachment and Attachment Cooling of Thermal Electrons in Oxygen and Oxygen Mixtures

1983 ◽  
Vol 36 (6) ◽  
pp. 831 ◽  
Author(s):  
R Hegerberg ◽  
RW Crompton
Keyword(s):  
Diffusion Coefficient ◽  
Cross Sections ◽  
Rate Coefficient ◽  
Resonance Energy ◽  
Sampling Technique ◽  
Rate Coefficients ◽  
Rotational Excitation ◽  
Attachment Rate ◽  
Excitation Cross Sections ◽  
Three Body

The Cavalieri electron density sampling technique has been used to measure the diffusion and attachment rate coefficients for thermal electrons in O2, and in O2–N2 and O2–C02 mixtures. The observed pressure dependence of the three-body attachment rate coefficient va/N2 is shown to be caused by the selective removal of electrons from the distribution at the attachment resonance energy, and the magnitude of this effect (so-called 'attachment cooling') is shown to be a measure of the magnitude of the rotational excitation cross sections in O2 and N2. Three-body rate coefficients for the formation of O2 involving O2, N2 and CO¯2 as third bodies have been found to be 2.2,011 and 3.5 X 10¯30 cm6 S¯l respectively. The value of the diffusion coefficient ND for thermal electrons in O2 is found to be (37 � 3) x 1021 cm¯1s¯1.

scholarly journals Laboratory determination of the rate coefficient for three-body recombination of oxygen atoms in nitrogen

2008 ◽  
Vol 113 (A4) ◽  
pp. n/a-n/a ◽  
Author(s):  
Dušan A. Pejaković ◽  
Konstantinos S. Kalogerakis ◽  
Richard A. Copeland ◽  
David L. Huestis
Keyword(s):  
Rate Coefficient ◽  
Laboratory Determination ◽  
Three Body ◽  
Body Recombination ◽  
Oxygen Atoms

scholarly journals Trapping Time of Resonant Orbits in Presence of Poynting - Robertson Drag

1983 ◽  
Vol 74 ◽  
pp. 397-410 ◽  
Author(s):  
R. Gonczi ◽  
Ch. Froeschlé ◽  
C. Froeschlé
Keyword(s):  
Initial Conditions ◽  
Gravitational Interaction ◽  
Resonance Region ◽  
Three Body Problem ◽  
Trapping Time ◽  
Resonant Orbits ◽  
Numerical Exploration ◽  
Orbital Resonances ◽  
Three Body ◽  
Special Case

AbstractWe study numerically the competition between the Poynting-Robertson drag and the gravitational interaction of grains with Jupiter near orbital resonances. The computations are based on the plane elliptic restricted three body problem. Numerical investigations show that the grains always cross the resonance region without any oscillation, except in the special case where the grains were initially inside the resonance. Such grains are temporarily trapped, then due to the drag they are ejected out of the resonance. The trapping time of a particle turns out to be much more important in the 3/2 and 2/1 commensurabilities than in the others.A numerical exploration of numerous orbits for different initial conditions and different sizes of grains has been performed. The trapping time appears to be closely connected to the size of the librator-type orbits regions; it increases with the initial eccentricity of the orbit, and is also proportional to the radius and the density of the particle.

Kinetics of aquation of the fluoropentaamminecobalt(III) ion

1970 ◽  
Vol 48 (7) ◽  
pp. 1054-1058 ◽  
Author(s):  
T. W. Swaddle ◽  
W. E. Jones
Keyword(s):  
Ionic Strength ◽  
Rate Coefficient ◽  
Hydrogen Ion ◽  
Fluoride Ion ◽  
Kcal Mole ◽  
First Order ◽  
Order Rate ◽  
Relationship Of ◽  
The Relationship ◽  
Kinetics Of

The kinetics of the hydrogen-ion-independent pathway for the replacement of fluoride in aqueous (NH3)5CoF2+ by H2O have been reinvestigated using a specific fluoride-ion electrode, with due regard for the concomitant autocatalytic loss of the ammine ligands. In perchlorate media of ionic strength 0.1 M, the first-order rate coefficient is 1.22 × 10−6 s−1 at 45°, and the kinetics are represented by ΔH* = 24.4 kcal mole−1 and ΔS* = −9 cal deg−1 mole−1 over the range 35–75° at least. The relationship of these data to those for the aquation of other species of the type ML5Xn+ is discussed.

Kinetics and Mechanism of the Thermal Decomposition of Hexaamminecobalt(III) and Aquopentaamminecobalt(III) Ions in Acidic Aqueous Solution

1974 ◽  
Vol 52 (15) ◽  
pp. 2751-2759 ◽  
Author(s):  
Anthony Martin Newton ◽  
Thomas Wilson Swaddle
Keyword(s):  
Aqueous Solution ◽  
Thermal Decomposition ◽  
Rate Coefficient ◽  
Initial Step ◽  
Hydrogen Ion ◽  
Minor Amount ◽  
Acidic Aqueous Solution ◽  
First Order ◽  
Independent Path ◽  
A Minor

The initial step in the thermal decomposition of Co(NH3)63+ in acidic aqueous solution is the replacement of NH3 by H2O, which occurs by a hydrogen-ion independent path, first order in complex, with rate coefficient k1 = 7.9 × 10−5 s−1 (140.4°), ΔH* = 36.6 kcal mol−1 and ΔS* = 10.7 cal deg−1 mol−1 in 0.1 M HClO4. For Co(NH3)5OH23+, there is a similar initial aquation path with k1 = 12.6 × 10−5 s−1 (140.6°), ΔH* = 41.9 kcal mol−1 and ΔS* = 24 cal deg−1 mol−1 and also a path first order in complex but inverse first order in [H+] with k2′ = 6.2 × 10−1 M s−1 (140.6°), ΔH* = 43.5 kcal mol−1 and ΔS* = 26.7 cal deg−1 mol−1 in perchlorate media of ionic strength 1.0 M. The effects of electrolyte type and concentration on the rates of these reactions have been examined. Subsequent aquation steps are relatively rapid because of the predominance of inversely [H+]-dependent pathways and are followed by redox to Co(H2O)62+, NH4+, N2, N2O, and a minor amount of O2. A mechanism involving OH and NH2 radicals is proposed for the redox step.

scholarly journals Explicitly correlated Sturmian functions for structure and collision three-body problems

2012 ◽  
Vol 388 (4) ◽  
pp. 042023
Author(s):  
G Gasaneo ◽  
L U Ancarani ◽  
K V Rodriguez ◽  
A L Frapiccini ◽  
V Y Gonzalez
Keyword(s):  
Explicitly Correlated ◽  
Three Body ◽  
Sturmian Functions

Three-body ion-neutral association

1974 ◽  
Vol 339 (1616) ◽  
pp. 13-28 ◽  
Keyword(s):  
Angular Momentum ◽  
Internal Energy ◽  
Orbital Angular Momentum ◽  
Rate Coefficient ◽  
Classical Mechanics ◽  
Impulse Approximation ◽  
Rate Coefficients ◽  
Quasi Equilibrium ◽  
Binary Collisions ◽  
Three Body

Consideration is given to the calculation of the rate coefficient of processes of the type A + + B + C → AB + + C. Classical mechanics is used. The impulse approximation is adopted and hard-sphere interactions are taken to describe C – A + and C – B collisions. Formulae are derived for the rate coefficients of binary collisions giving specified changes in the internal energy of the associating pair (without reference to their orbital angular momentum) and also of binary collisions giving specified changes in both the internal energy and in the square of the orbital angular momentum. By using quasi-equilibrium statistical theory, the rate co­efficient for three-body ion-neutral association is expressed in terms of either set of binary rate coefficients. Computations are carried out only Hg + + Hg + He → Hg + 2 + He. As expected, the predicted rate co­efficient is too high if specific account is not taken of the orbital angular momentum. If such account is taken excellent agreement is obtained with a measurement at 370 K made by Biondi (1953, 1972, private com­munication). The rate coefficient falls off slowly as the temperature is increased.

Laserspektroskopische Untersuchungen an nicht-stabilisierten N2(B3IIg, ν; = 13)-Molekülen / Laser Spectroscopic Studies on Non-stabilized N2(B3IIg, ν; = 13) molecules

1976 ◽  
Vol 31 (6) ◽  
pp. 673-674
Author(s):  
K. H. Becker ◽  
H. Engels ◽  
T. Tatarczyk
Keyword(s):  
Detection Limit ◽  
Emission Spectroscopy ◽  
Spectroscopic Studies ◽  
Rotational Analysis ◽  
Tunable Dye Laser ◽  
Recombination Processes ◽  
Three Body ◽  
Laser Spectroscopic ◽  
Body Recombination ◽  
Better Than

Unstabilized N2(B3IIg, ν = 13) quasi-molecules were analysed by excitation with a tunable dye-laser into the N2(C3IIu) state and observation of the following fluorescence to N2(B3IIg, ν) levels. The quasi-molecules are in equilibrium with the free nitrogen atoms. The detection limit of this technique is 105 molecules/cm3. By the same method, a rotational analysis of molecules stabilized into (B3IIg, ν ≦ 12) levels by three-body recombination processes was achieved with a resolution better than that reached by emission spectroscopy of the Lewis-Rayleigh afterglow

scholarly journals Measurement of the electron density and the attachment rate coefficient in silane/helium discharges

1985 ◽  
Vol 58 (3) ◽  
pp. 1344-1348 ◽  
Author(s):  
C. B. Fleddermann ◽  
J. H. Beberman ◽  
J. T. Verdeyen
Keyword(s):  
Electron Density ◽  
Rate Coefficient ◽  
Attachment Rate
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