scholarly journals Vibrational Excitation Cross-Section by Positron Impact: A Wave-Packet Dynamics Study

Atoms ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 64
Author(s):  
Luis A. Poveda ◽  
Marcio T. do N. Varella ◽  
José R. Mohallem
Keyword(s):  
Wave Packet ◽  
Cross Section ◽  
Energy Surface ◽  
Excitation Cross Section ◽  
Vibrational Mode ◽  
Vibrational Excitation ◽  
Spherically Symmetric ◽  
Positron Impact ◽  
Wave Packet Dynamics ◽  
Good Agreement

The vibrational excitation cross-section of a diatomic molecule by positron impact is obtained using wave-packet propagation techniques. The dynamics study was carried on a two-dimensional potential energy surface, which couples a hydrogenlike harmonic oscillator to a positron via a spherically symmetric correlation polarization potential. The cross-section for the excitation of the first vibrational mode is in good agreement with previous reports. Our model suggests that a positron couples to the target vibration by responding instantly to an interaction potential, which depends on the target vibrational coordinate.

scholarly journals A Study of the Vibrational Excitation of H2 by Measurements of the Drift Velocity of Electrons in H2−Ne Mixtures

1988 ◽  
Vol 41 (4) ◽  
pp. 573 ◽  
Author(s):  
JP England ◽  
MT Elford ◽  
RW Crompton
Keyword(s):  
Cross Section ◽  
Drift Velocity ◽  
Cross Sections ◽  
Excitation Cross Section ◽  
Vibrational Excitation ◽  
Pure Hydrogen ◽  
Velocity Data ◽  
Highly Sensitive ◽  
Hydrogen Mixtures ◽  
Made In

Measurements of electron drift velocities have been made in 1�160% and 2�892% hydrogen-neon mixtures at 294 K and values of EI N from 0�12 to 1�7 Td. The measurements are highly sensitive to the region of the threshold of the v = 0 → 1 vibrational excitation cross section for hydrogen and have enabled more definitive tests of proposed cross sections to be made than was possible using drift velocity data for H2−He and H2−Ar mixtures. The theoretical v = 0 → 1 vibrational excitation cross section of Morrison et al. (1987) is shown to be incompatible with the present measurements. A new set of hydrogen cross sections has been derived from the available electron swarm measurements in pure hydrogen and hydrogen mixtures.

QUASICLASSICAL TRAJECTORY CALCULATION OF THE CHEMICAL REACTION Ba + HI

2009 ◽  
Vol 08 (05) ◽  
pp. 827-835 ◽  
Author(s):  
LI YAO ◽  
YONGLU LIU ◽  
HAIYANG ZHONG ◽  
WANGHE CAO
Keyword(s):  
Potential Energy ◽  
Potential Energy Surface ◽  
Cross Section ◽  
Reaction Cross Section ◽  
Energy Surface ◽  
Reaction Cross ◽  
Trajectory Calculation ◽  
Quasiclassical Trajectory Calculation ◽  
Rotational Distribution ◽  
Good Agreement

This paper reports the results of quasiclassical trajectory calculation on extended London-Eyring-Polanyi-Sato potential energy surface for the reaction between Ba atom and HI . The rotational distribution, vibrational distribution, reaction cross section, and rotational alignment are all obtained and they are under detailed discussion for product BaI . The calculated results are in good agreement with the experimental results.

EFFECTS OF ROTATIONAL AND VIBRATIONAL EXCITATION ON THE STEREODYNAMICS OF THE O (D-1) + HCl → OH + Cl REACTION

2009 ◽  
Vol 08 (06) ◽  
pp. 1177-1184 ◽  
Author(s):  
QIANG WEI ◽  
VICTOR WEI-KEH WU ◽  
BO ZHOU
Keyword(s):  
Cross Sections ◽  
Collision Energy ◽  
Energy Surface ◽  
Vibrational Excitation ◽  
Classical Trajectory ◽  
Rotational Excitation ◽  
Title Reaction ◽  
Vibrational Excitations ◽  
Product Vector ◽  
Good Agreement

The stereodynamics of the title reaction on the ground 1 1A′ potential energy surface (PES) has been studied using quasi-classical trajectory (QCT) method. Collision energy of 6.4 kcal/mol is considered, and vector properties including angular momentum alignment distributions and polarization-dependent differential cross-sections (PDDCS) of the product OH are presented. Furthermore, the influence of reagent rotational excitation and vibrational excitation on the product vector properties has also been studied in the present work. The results indicate that the distribution of the P(θr) and P(ϕr) are sensitively affected by the rotational and vibrational excitation. The rotational excitation decreases the degree of alignment and orientation, while vibrational excitation increases the degree of alignment and orientation. The PDDCS (2π/σ)(dσ20/dωt) and (2π/σ)(dσ22+/dωt) are sensitively influenced by rotational and vibrational excitations, while the PDDCS ((2π/σ)(dσ00/dωt)) and (2π/σ)(dσ21-/dωt) are not. The preference of forward scattering has been found from the results of PDDCS ((2π/σ)(dσ00/dωt)), which is in good agreement with the experimental results.

Wave packet dynamics of the N(4S)+O2(X 3Σg−)→NO(X 2Π)+O(3P) reaction on the X 2A′ potential energy surface

2001 ◽  
Vol 115 (7) ◽  
pp. 3208-3214 ◽  
Author(s):  
Paolo Defazio ◽  
Carlo Petrongolo ◽  
Stephen K. Gray ◽  
Carolina Oliva
Keyword(s):  
Potential Energy ◽  
Wave Packet ◽  
Potential Energy Surface ◽  
Energy Surface ◽  
Wave Packet Dynamics

The radiation chemistry of nitrogen: primary neutral dissociative excitation yield and the isotopic exchange mechanism

1978 ◽  
Vol 56 (2) ◽  
pp. 147-154 ◽  
Author(s):  
A. W. Boyd ◽  
O. A. Miller ◽  
C. Willis
Keyword(s):  
Cross Section ◽  
Isotopic Exchange ◽  
Significant Contribution ◽  
Excitation Cross Section ◽  
Product Yield ◽  
Radiation Chemistry ◽  
Dissociative Excitation ◽  
Dose Rates ◽  
Isotopic Exchange Reaction ◽  
Good Agreement

Measurements of the yield of NO2 in N2–NO mixtures give a neutral dissociative excitation yield of [Formula: see text] in good agreement with those derived from excitation cross-section measurements and from product yield measurement in the radiolysis of N2–O2 mixtures.The dependence of exchange yields in the radiolysis of 28N2–30N2 mixtures on pressure, O2 concentration, and dose-rate has been measured. The results are consistent with a significant contribution to these yields from the isotopic exchange reaction of N+ with N2. They also indicate that dose-rates of the order of >1022 eV g−1 s−1 are required for the N2+ ions to contribute to the exchange yield.

scholarly journals Low Energy Electron Scattering From H2

1990 ◽  
Vol 43 (5) ◽  
pp. 665 ◽  
Author(s):  
MJ Brunger ◽  
Stephen J Buckman ◽  
DS Newman
Keyword(s):  
Cross Section ◽  
Electron Scattering ◽  
Cross Sections ◽  
Incident Energy ◽  
Vibrational Excitation ◽  
Elastic Electron Scattering ◽  
Total Cross Sections ◽  
Threshold Excitation ◽  
Low Energy Electron ◽  
Good Agreement

Absolute differential and integrated total cross sections for elastic electron scattering and vibrational excitation of molecular hydrogen have been measured at an incident energy of 1�5 eV. The results are presented and discussed with particular reference to a long-standing impasse which has existed between and within experiment and theory for the near-threshold excitation of the first vibrational state of H2. The integral vibrational cross section is in good agreement (�10%) with previous beam experiments and theory but is some 60% higher than the cross section derived from a swarm analysis.

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