Ab initio calculation of the cross sections for electron impact vibrational excitation of CO via the 2Π shape resonance

The results of electron drift and diffusion measurements in parahydrogen have been analysed to determine the cross sections for momentum transfer and for rotational and vibrational excitation. The limited number of possible excitation processes in parahydrogen and the wide separation of the thresholds for these processes make it possible to determine uniquely the J = 0 → 2 rotational cross section from threshold to 0.3 eV. In addition, the momentum transfer cross section has been determined for energies less than 2 eV and it is shown that, near threshold, a vibrational cross section compatible with the data must lie within relatively narrow limits. The problems of uniqueness and accuracy inherent in the swarm method of cross section analysis are discussed. The present results are compared with other recent theoretical and experimental determinations; the agreement with the most recent calculations of Henry and Lane is excellent.

Download Full-text

Experimental Study of Low Energy e-O2 Collision Processes

Zeitschrift für Naturforschung A ◽

10.1515/zna-1971-1008 ◽

1971 ◽

Vol 26 (10) ◽

pp. 1617-1625 ◽

Cited By ~ 144

Author(s):

F. Linder ◽

H. Schmidt

Keyword(s):

Angular Dependence ◽

Cross Sections ◽

Vibrational Excitation ◽

Resonance Scattering ◽

Spectroscopic Constants ◽

Extended Model ◽

Vibrational Levels ◽

Electronically Excited ◽

The Cross ◽

Electronic Ground

Abstract Elastic scattering, vibrational excitation to v=1, 2, 3, 4 of the electronic ground state, and electronic excitation to the states a1Δ g and b1Σg+ of O2 have been measured in a crossed beam apparatus for collision energies from nearly 0 eV to 4 eV. Differential and integral cross sections have been determined and calibrated on an absolute scale. From 15 vibrational levels of O2-, which could be observed as resonances in the cross sections, the spectroscopic constants for the vibrational structure of O2- have been derived: ωe = 135 meV and ωeχe = 1 meV. The cross sections for vibrational excitation have the order of 10-18 cm2. eV for the larger resonance peaks. Detailed cross sections have been listed in Table 1. The half width of the resonance can be estimated to Γ ≈ 0.5 meV, which corresponds to a lifetime tof 10-12 sec for the O2- states. The angular dependence of pure resonance scattering is rather flat and not in accordance with the simplest theoretical model. An analysis of the angular dependence and of the rotational structure of the resonance in a somewhat extended model have been performed. - No electronically excited O2-states could be detected in the energy range up to 3 eV.

Download Full-text

Calculated low-energy electron-impact vibrational excitation cross sections for CO2molecule

Plasma Sources Science and Technology ◽

10.1088/0963-0252/25/6/06lt02 ◽

2016 ◽

Vol 25 (6) ◽

pp. 06LT02 ◽

Cited By ~ 9

Author(s):

V Laporta ◽

J Tennyson ◽

R Celiberto

Keyword(s):

Electron Impact ◽

Cross Sections ◽

Vibrational Excitation ◽

Low Energy ◽

Energy Electron ◽

Excitation Cross Sections ◽

Low Energy Electron

Download Full-text

Absolute cross sections for D2 Lyman and Werner band excitation by controlled electron impact

Canadian Journal of Physics ◽

10.1139/p84-001 ◽

1984 ◽

Vol 62 (1) ◽

pp. 1-9 ◽

Cited By ~ 6

Author(s):

K. Becker ◽

J. W. McConkey

Keyword(s):

Energy Range ◽

Electron Impact ◽

Cross Section ◽

Cross Sections ◽

Impact Energy ◽

Emission Cross Section ◽

Direct Excitation ◽

The Cross ◽

Impact Energies

We have studied the Lyman [Formula: see text] and Werner [Formula: see text] band emissions produced by 20–500-eV electrons incident on molecular deuterium, D2. Emission cross sections of (3.7 ± 0.9) × 10−17 cm2 for the B → X and (3.54 ± 0.74) × 10−17 cm2 for the C → X system have been determined at 100-eV impact energy. Cascading did not play an important role in the [Formula: see text] emission, but it was shown to affect the [Formula: see text] emission seriously, particularly for impact energies below 50 eV. We estimate the cross section for direct excitation of the [Formula: see text] state and the cascade cross section to be 2.95 × 10−17 and 0.75 × 10−17 cm2, at 100 eV respectively. The cascade cross section is 20 ± 10% of the total B → X emission cross section, and is essentially constant in the energy range 300–50 eV, but increases significantly for lower impact energies, e.g., to 40 ± 15% at 27.5 eV. The cross section for the atomic 2p → 1s Lyman α emission from D2 has also been measured and the value of 1.00 × 10−17 cm2 at 100 eV is 20% smaller than the cross section for Lyman α emission from H2.

Download Full-text

Excitation of singly-ionized barium ions by electron impact

Canadian Journal of Physics ◽

10.1139/p70-037 ◽

1970 ◽

Vol 48 (3) ◽

pp. 275-278 ◽

Cited By ~ 3

Author(s):

J. Davis ◽

S. Morin

Keyword(s):

Energy Range ◽

Electron Impact ◽

Cross Section ◽

Cross Sections ◽

Experimental Measurements ◽

Barium Ions ◽

Semiclassical Method ◽

The Cross

We present cross-section calculations for excitation of singly-ionized barium ions by electron impact over the energy range from 3 to 100 eV. The cross sections were evaluated using Burgess' semiclassical method. Finally, our predictions are compared with two other current techniques and some recent experimental measurements. The agreement was found to be good.

Download Full-text