DISSOCIATIVE PHOTOIONIZATION CROSS SECTIONS OF N2AND O2FROM 100 TO 800 eV

Stolte, Wayne C.; He, Z. X.; Cutler, J. N.; Lü, Ying; Samson, James A. R.

doi:10.1006/adnd.1998.0775

Cited by 36 publications

(34 citation statements)

References 11 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The present work utilizes the measured total electron impact cross section for the N 2 → N 2 + process and photoionization oscillator strengths of the X 2 Σ g + − X 1 Σ g + , A 2 Π u − X 1 Σ g + and B 2 Σ u + − X 1 Σ g + band systems to obtain the cross sections for the X 2 Σ g + , A 2 Π u and B 2 Σ u + states of N 2 + . The ionization oscillator strengths are derived from photoionization experimental measurements of Samson et al [1977, 1987], Lee [1977], Plummer et al [1977], Stolte et al [1998], and photoionization data compiled by Conway [1988]. The photoionization measurements are intrinsically more accurate on an absolute scale than the less easily controlled electron beam experiments.…”

Section: Introductionmentioning

confidence: 99%

Evaluation of electron impact excitation of N₂ X ¹Σ_g⁺(0) into the N₂⁺ X ²Σ_g⁺(v), A ²Π_u(v), and B ²Σ_u⁺(v) states

Shemansky

Liu

2005

J. Geophys. Res.

View full text Add to dashboard Cite

Published experimental integrated electric dipole photoionization oscillator strengths (fij) have been applied to the determination of absolute electron impact excitation cross sections of the N2 X 1Σg+(0) state into the N2+ X 2Σg+(v), A 2Πu(v), and B 2Σu+(v) states. The required relative electron impact cross section shape functions from threshold to energy values, limited by the imposition of relativistic effects at the high end, are established in this work by extracting accurate analytic functions from a critical review of extensive published experimental results. The cross sections examined here are important benchmarks used in establishing absolute values for critical rate processes in aeronomy. The determination of the absolute cross sections using the derived fij is accomplished through the physical relationship to a modified Born approximation analytic function that defines the electron impact shape functions. The zero order term of the analytic function is established in value relative to the remaining terms through shape analysis of the experimental electron impact results. The value of fij fixes the absolute value of the zero order term, determining the cross sections over the entire electron impact energy range. It is argued that this methodology is the most accurate approach at this time because of the existence of the intrinsically more accurate photometrically dermined fij. The critical quantities in atmospheric process applications are the branching ratios of excitation into the N2+ X 2Σg+, A 2Πu, and B 2Σu+ states. The N2+ (X 2Σg+, A 2Πu, B 2Σu+) partitioning within the total ionization cross section has been a source of disagreement in the literature, in spite of the fact that substantial effort has been expended in establishing acceptably accurate values. The present work establishes accurate cross sections for these states over the entire practical energy range required for research in atmospheric N2 physical chemistry. The accuracy of the results obtained here are verified by consistency with the most reliably established past experimental electron impact cross sections, in agreement with the independently established total N2+ cross section. We provide analytic collision strengths for the vibrational levels of the N2+ X 2Σg+, A 2Πu, and B 2Σu+ states, allowing establishment of rate coefficients for the system, at an estimated error ≤±8%.

show abstract

Section: Introductionmentioning

confidence: 99%

Evaluation of electron impact excitation of N₂ X ¹Σ_g⁺(0) into the N₂⁺ X ²Σ_g⁺(v), A ²Π_u(v), and B ²Σ_u⁺(v) states

Shemansky

Liu

2005

J. Geophys. Res.

View full text Add to dashboard Cite

show abstract

“…1(e), are normalized ion yields measured as a function of photon energy with the microwave discharge on or off, and C qþ is a constant dependent on the number density of nitrogen atoms and the ion-collection efficiency of the apparatus. Absolute data for single and multiple photoionization of N 2 [21] were used to determine values for the constants C qþ . The parameter f ¼ ½nðN on 2 Þ=nðN off 2 Þ, with nðN on 2 Þ and nðN off 2 Þ being number densities of N 2 with the microwave discharge on or off, represents the fraction of N 2 molecules that do not dissociate in the discharge.…”

mentioning

confidence: 99%

K-Shell X-Ray Spectroscopy of Atomic Nitrogen

et al. 2011

View full text Add to dashboard Cite

Absolute K-shell photoionization cross sections for atomic nitrogen have been obtained from both experiment and state-of-the-art theoretical techniques. Because of the difficulty of creating a target of neutral atomic nitrogen, no high-resolution K-edge spectroscopy measurements have been reported for this important atom. Interplay between theory and experiment enabled identification and characterization of the strong 1s → np resonance features throughout the threshold region. An experimental value of 409.64±0.02 eV was determined for the K-shell binding energy.

show abstract

“…At the same time, the total molecular photoionization cross sections presented by Henke et al (1993) in the energy region 50-30,000 eV are underestimated (Stolte et al 1998 Stolte et al (1998) over the photon energy range of 100-800 eV. These partial cross sections were found to follow a power-law as (Stolte et al 1998) …”

Section: Photoionization Of Neutral Species Of the Atmospherementioning

confidence: 87%

“…Below 15.5 nm the total photoionization cross section of N 2 or O 2 determines the photoabsorption cross section of N 2 or O 2 , respectively (see, e.g., Fennelly and Torr 1992), i.e., the use of the total photoionization cross sections of N 2 and O 2 allows to calculate the average photoabsorption cross sections of N 2 and O 2 , respectively. The resulting average photoabsorption cross sections of N 2 and O 2 , and Table 2 Constant multiplication factors and exponents derived by Stolte et al (1998) Table 3.…”

Section: Photoionization Of Neutral Species Of the Atmospherementioning

confidence: 99%

Photochemistry of Ions at D-region Altitudes of the Ionosphere: A Review

Павлов

2013

Surv Geophys

View full text Add to dashboard Cite

show abstract

DISSOCIATIVE PHOTOIONIZATION CROSS SECTIONS OF N2AND O2FROM 100 TO 800 eV

Cited by 36 publications

References 11 publications

Evaluation of electron impact excitation of N₂ X ¹Σ_g⁺(0) into the N₂⁺ X ²Σ_g⁺(v), A ²Π_u(v), and B ²Σ_u⁺(v) states

Evaluation of electron impact excitation of N₂ X ¹Σ_g⁺(0) into the N₂⁺ X ²Σ_g⁺(v), A ²Π_u(v), and B ²Σ_u⁺(v) states

K-Shell X-Ray Spectroscopy of Atomic Nitrogen

Photochemistry of Ions at D-region Altitudes of the Ionosphere: A Review

Contact Info

Product

Resources

About

DISSOCIATIVE PHOTOIONIZATION CROSS SECTIONS OF N2AND O2FROM 100 TO 800 eV

Cited by 36 publications

References 11 publications

Evaluation of electron impact excitation of N2 X 1Σg+(0) into the N2+ X 2Σg+(v), A 2Πu(v), and B 2Σu+(v) states

Evaluation of electron impact excitation of N2 X 1Σg+(0) into the N2+ X 2Σg+(v), A 2Πu(v), and B 2Σu+(v) states

K-Shell X-Ray Spectroscopy of Atomic Nitrogen

Photochemistry of Ions at D-region Altitudes of the Ionosphere: A Review

Contact Info

Product

Resources

About

Evaluation of electron impact excitation of N₂ X ¹Σ_g⁺(0) into the N₂⁺ X ²Σ_g⁺(v), A ²Π_u(v), and B ²Σ_u⁺(v) states

Evaluation of electron impact excitation of N₂ X ¹Σ_g⁺(0) into the N₂⁺ X ²Σ_g⁺(v), A ²Π_u(v), and B ²Σ_u⁺(v) states