scholarly journals Nonresonant effects in one- and two-photon transitions

2002 ◽  
Vol 80 (6) ◽  
pp. 633-644 ◽  
Author(s):  
U D Jentschura ◽  
P J Mohr
Keyword(s):  
Cross Sections ◽  
Atomic Hydrogen ◽  
Rayleigh Scattering ◽  
Energy Levels ◽  
Experimental Accuracy ◽  
Differential Measurement ◽  
Resonance Effects ◽  
Two Photon ◽  
Scattering Cross ◽  
Scattering Cross Sections

We investigate nonresonant contributions to resonant Rayleigh-scattering cross sections of atoms. The problematic nonresonant contributions set a limit to the accuracy to which atomic spectra determine energy levels. We discuss the off-resonance effects in one-photon transitions. We also show that off-resonance contributions for the 1S–2S two-photon transition in atomic hydrogen are negligible at current and projected levels of experimental accuracy. The possibility of a differential measurement for the detection of off-resonance effects in one-photon transitions in atomic hydrogen is discussed. PACS Nos.: 31.15-p, 12.20Ds

scholarly journals Scattering and Absorption Cross-sections of Atmospheric Gases in the Ultraviolet-Visible Wavelength Range (307–725 nm)

2020 ◽  
Author(s):  
Quanfu He ◽  
Zheng Fang ◽  
Ofir Shoshamin ◽  
Steven S. Brown ◽  
Yinon Rudich
Keyword(s):  
Refractive Index ◽  
Wavelength Range ◽  
Cross Sections ◽  
Rayleigh Scattering ◽  
Dispersion Relations ◽  
Optical Absorption Spectroscopy ◽  
Absorption Cross ◽  
Atmospheric Gases ◽  
Scattering Cross ◽  
Scattering Cross Sections

Abstract. Accurate Rayleigh scattering and absorption cross-sections of atmospheric gases are essential for understanding the propagation of electromagnetic radiation in planetary atmospheres. Accurate extinction cross-sections are also essential for calibrating high finesse optical cavities and differential optical absorption spectroscopy and for accurate remote sensing. In this study, we measured the scattering and absorption cross-sections of carbon dioxide, nitrous oxide, sulfur hexafluoride, oxygen, and methane in the continuous wavelength range of 307–725 nm using Broadband Cavity Enhanced Spectroscopy (BBCES). The experimentally derived Rayleigh scattering cross-sections for CO2, N2O, SF6, O2, and CH4 agree with refractive index-based calculations, with a difference of 1.5 % and 1.1 %, 1.5 %, 2.9 %, and 1.4 % on average, respectively. The O2-O2 collision-induced absorption and absorption by methane are obtained with high precision at the 0.8 nm resolution of our BBCES instrument in the 307–725 nm wavelength range. New dispersion relations for N2O, SF6, and CH4 were derived using data in the UV-vis wavelength range. This study provides improved refractive index dispersion relations, n-based Rayleigh scattering cross-sections, and absorption cross-sections for these gases.

scholarly journals Rayleigh Scattering Cross Sections

Radio Science ◽  
1972 ◽  
Vol 7 (10) ◽  
pp. 937-942 ◽  
Author(s):  
R. E. Kleinman ◽  
T. B. A. Senior
Keyword(s):  
Cross Sections ◽  
Rayleigh Scattering ◽  
Scattering Cross ◽  
Scattering Cross Sections

Measurement of large angle Rayleigh scattering cross sections for 39.5, 40.1 and 45.4 keV photons in elements with 26 ≤ Z ≤ 83

2017 ◽  
Vol 128 ◽  
pp. 125-131 ◽  
Author(s):  
Arun Upmanyu ◽  
Gurjot Singh ◽  
Heena Duggal ◽  
H.S. Kainth ◽  
Atul Bhalla ◽  
...  
Keyword(s):  
Cross Sections ◽  
Rayleigh Scattering ◽  
Large Angle ◽  
Scattering Cross ◽  
Scattering Cross Sections
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