Three‐body ion–molecule association rate coefficients as a function of temperature and cluster size: NO−3(HNO3)n+HCl→MNO−3 (HNO3)n(HCl)

1984 ◽  
Vol 81 (6) ◽  
pp. 2639-2645 ◽  
Author(s):  
A. A. Viggiano
Keyword(s):  
Cluster Size ◽  
Rate Coefficients ◽  
Association Rate ◽  
Three Body

scholarly journals The Formation of Complex Interstellar Molecules by Radiative Association

1980 ◽  
Vol 87 ◽  
pp. 317-321
Author(s):  
E. Herbst
Keyword(s):  
Statistical Theory ◽  
Reaction Rate ◽  
Rate Coefficients ◽  
Association Rate ◽  
Interstellar Molecules ◽  
Temperature Range ◽  
Radiative Association ◽  
Association Reaction ◽  
Three Body ◽  
Good Agreement

A new statistical theory of ion-molecule association reaction rate coefficients has been formulated and found to give good agreement with three-body association rate coefficients studied in the laboratory in the temperature range 100-300 K (Herbst 1979a). The theory indicates that certain radiative association reactions proceed rapidly at low interstellar temperatures to produce complex interstellar molecules, as suggested by Smith and Adams (1978).

scholarly journals The Formation of Interstellar Molecules via Radiative Association Reactions

1980 ◽  
Vol 87 ◽  
pp. 323-324
Author(s):  
David Smith ◽  
Nigel G. Adams
Keyword(s):  
Rate Coefficients ◽  
Rate Data ◽  
Association Rate ◽  
Interstellar Molecules ◽  
Ion Molecule Reactions ◽  
Radiative Association ◽  
Temperature Dependences ◽  
Association Reaction

The radiative association rate coefficients and their temperature dependences have been estimated for several likely interstellar ion-molecule reactions from laboratory collisional association rate data. They include the CH3+ + H2 and CH3+ + H2O reactions, which we suggest lead to CH4 and CH3OH respectively, and the critical association reaction C+ + H2.

scholarly journals Investigation of a Collisional Radiative Model for Laser-Produced Plasmas

Atoms ◽  
2020 ◽  
Vol 8 (3) ◽  
pp. 52
Author(s):  
Nicholas L. Wong ◽  
Fergal O’Reilly ◽  
Emma Sokell
Keyword(s):  
Radiative Recombination ◽  
Rate Coefficients ◽  
Ion Distribution ◽  
Ion Distributions ◽  
Nist Database ◽  
Collisional Radiative Model ◽  
Radiative Model ◽  
Collisional Ionization ◽  
Three Body ◽  
Body Recombination

Plasmas of a variety of types can be described by the collisional radiative (CR) model developed by Colombant and Tonan. From the CR model, the ion distribution of a plasma at a given electron temperature and density can be found. This information is useful for further simulations, and due to this, the employment of a suitable CR model is important. Specifically, ionization bottlenecks, where there are enhanced populations of certain charge states, can be seen in these ion distributions, which in some applications are important in maintaining large amounts of a specific ion. The present work was done by implementing an accepted CR model, proposed by Colombant and Tonon, in Python and investigating the effects of variations in the ionization energy and outermost electron subshell occupancy term on the positions of ionization bottlenecks. Laser Produced Plasmas created using a Nd:YAG laser with an electron density of ∼ne = 1021 cm−3 were the focus of this work. Plots of the collisional ionization, radiative recombination, and three-body recombination rate coefficients as well as the ion distribution and peak fractional ion population for various elements were examined. From these results, it is evident that using ionization energies from the NIST database and removing the orbital occupancy term in the CR model produced results with ionization bottlenecks in expected locations.

Statistical processes of aggregation and polymerization

1965 ◽  
Vol 61 (2) ◽  
pp. 475-495 ◽  
Author(s):  
P. Whittle
Keyword(s):  
Kinetic Equation ◽  
Cluster Size ◽  
Kinetic Equations ◽  
Gibbs Distribution ◽  
Single Pair ◽  
Equilibrium Concept ◽  
Expected Number ◽  
Association Rate ◽  
Bond Model ◽  
Quantities Of Interest

AbstractWe study processes in which units (particles) associate into clusters, which are then also capable of dissociation. Such processes are discussed generally in section 2, where a stochastic kinetic equation (10) is proposed which bridges the gap between the conventional kinetic equations (8) and the statistical equilibrium concept of the Gibbs distribution.In section 4 we consider the equilibrium behaviour of a process for which the association rate of two units which are already bound to j and k other units respectively has the form (21). This is very much more general than the equi-reactive bond model usually discussed. The principal results are given in Theorem 1; from a single pair of equations (28) and (29) based on the Hj of (21) one can determine critical points, expected number of bonds, the distribution and moments of cluster size, and most other quantities of interest. This is without reference to any other consideration, such as kinetic or stoichiometric relations.Some particular cases are worked through in section 5. The classic Flory-Stockmayer results for units with f equi-reactive sites are obtained systematically and economically, with all parameters in terms of physically given quantities. Another type of example seems to indicate the existence of a second critical point.Corresponding results for the case of several types of unit are stated and illustrated in section 6.

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.

Laboratory studies of electron attachment and detachment processes of aeronomic interest

1969 ◽  
Vol 47 (10) ◽  
pp. 1783-1793 ◽  
Author(s):  
A. V. Phelps
Keyword(s):  
Cross Sections ◽  
Ion Beam ◽  
Electron Attachment ◽  
Negative Ions ◽  
High Energy ◽  
Low Energy ◽  
Rate Coefficients ◽  
Dissociative Attachment ◽  
Three Body ◽  
Energy Processes

Techniques for the study of electron attachment and detachment are reviewed. The rate coefficients for the various processes of aeronomic interest are then discussed. The rates of three-body and dissociative attachment by thermal electrons have been successfully determined by swarm techniques and by high frequency studies of electrons produced by high energy particles and by photoionization. Collisional and associative detachment rates for thermal energy negative ions have been measured using the swarm and flowing afterglow techniques. Radiative attachment rates for some atmospheric negative ions have been calculated from measurements of photodetachment cross sections using crossed photon and ion beam techniques. Electron beam studies and measurements of ion kinetic energy have provided much useful information regarding the dissociative attachment process and the structure of molecular negative ions. Rate coefficients for low energy processes such as the three-body attachment to O2, the radiative attachment to O, and the associative detachment of O− in collisions with various atmospheric gases are reasonably well known. Other possibly important low energy processes, such as dissociative attachment to O3, radiative attachment to O2, and the associative detachment of O2− are less well known.

Sign in / Sign up

Export Citation Format

Share Document