Quick search Find article
Quick search
Find article

ANALYSIS OF ELECTRON-IMPACT EXCITATION AND EMISSION OF THE npσ1Σ+ u AND npπ1Π u RYDBERG SERIES OF H2

FREE ISSUE

Michèle Glass-Maujean1, Xianming Liu2 and Donald E. Shemansky2

Show affiliations


Calculated and recently measured photoabsorption transition probabilities of the H2 npσ1Σ+ u and npπ1Π u X 1Σ+ g band systems have been examined with high-resolution (Δλ = 95-115 mÅ) electron-impact induced emission spectra obtained previously by Jonin et al. and Liu et al. When localized rovibronic coupling is insignificant, transition probabilities calculated with the adiabatic approximation are found to be generally consistent with experiment. However, in the presence of significant coupling, the transition probabilities obtained from a nonadiabatic calculation of B'1Σ+ u , D 1Π+ u , $B^{\prime \prime }\bar{B}\,^{1}\Sigma _{u}^{+}$, D'1Π+ u , and 5pσ1Σ+ u state coupling give better agreement with the experimental spectra. Emission yields obtained by comparison of the calculated and experimental spectra are also consistent with the measured predissociation and autoionization yields. In addition, more accurate excitation and emission cross sections and nonradiative yields have been obtained for a number of the npσ1Σ+ u and npπ1Π u states. The results obtained in the present investigation lead to a significantly more accurate calibration of the Cassini UVIS instrument and laboratory spectrometers in the range 790-920 Å. They are also an important step toward an accurate model of extreme ultraviolet H2 auroral and dayglow emissions in the outer planet atmospheres.


Keywords

methods: laboratory; molecular processes; ultraviolet: ISM


Dates

Issue 1 (2009 January)

Received 2008 April 14, accepted for publication 2008 August 25

Published 2008 December 23



View by subject




Export








Please login to access our web services, or create an account if you don't yet have one.

You must have cookies enabled in your web browser to be able to login.

Username
Password

Forgotten your password? Get a new one here.