Transfer of Electronic Excitation between the 72P1/2 and 72P3/2 States of Cesium Induced by Collisions with Cesium Atoms

1974 ◽  
Vol 52 (17) ◽  
pp. 1641-1647 ◽  
Author(s):  
Paul W. Pace ◽  
J. B. Atkinson
Keyword(s):  
Cross Sections ◽  
Electronic Excitation ◽  
Empirical Relationship ◽  
Nitrogen Laser ◽  
Mixing Process ◽  
Transfer Processes ◽  
Radiation Trapping ◽  
Structure Splitting ◽  
The Cross ◽  
Cesium Atoms

The method of sensitized fluorescence has been employed to investigate the [Formula: see text] excitation transfer processes in cesium induced in collisions with ground state cesium atoms. The cesium vapor density was kept sufficiently low to enable the cross sections for the mixing process to be determined under single collision conditions and to ensure that radiation trapping and quenching were negligible. A nitrogen laser pumped dye laser was used to excite the cesium atoms to each of the 72P levels in turn and measurements of the relative intensities of fluorescence yielded the following cross sections: [Formula: see text] These results are consistent with the empirical relationship between the magnitude of the cross sections and the fine structure splitting that has previously been determined for the alkalis.

Transfer of Electronic Excitation between the 62P3/2 and 62P1/2 States of Rubidium Induced by Collisions with Rubidium Atoms

1974 ◽  
Vol 52 (17) ◽  
pp. 1635-1640 ◽  
Author(s):  
Paul W. Pace ◽  
J. B. Atkinson
Keyword(s):  
Fine Structure ◽  
Cross Sections ◽  
Electronic Excitation ◽  
Empirical Relationship ◽  
Optical Excitation ◽  
Nitrogen Laser ◽  
Rubidium Vapor ◽  
Rubidium Atoms ◽  
Structure Splitting ◽  
The Cross

The cross sections for excitation transfer between the 62P fine structure levels of rubidium, induced in collisions with ground state rubidium atoms, have been measured using a nitrogen laser pumped dye laser as the optical excitation source in a fluorescence experiment. Rubidium vapor was irradiated with each component of the 2P rubidium doublet in turn, and measurements of the relative intensities of fluorescence yielded the following cross sections: [Formula: see text] These results are consistent with the empirical relationship between the magnitude of the cross sections and the fine structure splitting that has previously been established for the alkalis.

Optische Anregung beim Ladungsaustausch von Edelgasionen für Stoßenergien von 5 bis 300 eVolt

1968 ◽  
Vol 23 (7) ◽  
pp. 970-978
Author(s):  
H. Schlumbohm
Keyword(s):  
Charge Transfer ◽  
Kinetic Energy ◽  
Internal Energy ◽  
Excited States ◽  
Cross Sections ◽  
Ground Level ◽  
High Rate ◽  
Transfer Processes ◽  
The Cross ◽  
Threshold Energies

Measurements of the photoemission caused by collisions of ground level He+- and Ne+-ions with Ar- and Kr-atoms have shown several multipletts of Ar II and Kr II within the investigated wavelength range of 3500 to 5500 A. At a high rate the charge transfer processes occur into excited states of Ar* and Kr*. The reactions are endothermic with a deficit of internal energy between 6 and 19 eV.The cross sections measured for several chosen transitions start at characteristic threshold energies between 10 and 25 eV. Above the threshold the cross sections rise slowly with increasing energy when Ne* is the colliding ion and very fast for He+. Above 50 to 100 eV the cross sections show nearly constant values. — The minimum kinetic energy values are calculated, which can just fill up the deficits of internal energy, and are shown to be equal to the measured threshold energies. Thus it follows that the pseudo-crossing of the potential energy curves of the quasimolecules occurs at an energy value equal to the asymptotic level of the above curve.

Experimental evaluation of the cross-sections for the Cs(6D)→Cs(7PJ) and Cs(6D5/2)→Cs(6D3/2) collisional transfer processes induced by He and Ar

2006 ◽  
Vol 61 (6) ◽  
pp. 623-633 ◽  
Author(s):  
Tiffany L. Correll ◽  
Vlasta Horvatic ◽  
Nicoló Omenetto ◽  
James D. Winefordner ◽  
Cedomil Vadla
Keyword(s):  
Cross Sections ◽  
Experimental Evaluation ◽  
Transfer Processes ◽  
The Cross

Numerical investigation of the effect of the injection angle on the spray structures of an air-blast atomizer

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Sheng Chen ◽  
Yuming Xing ◽  
Xin Liu ◽  
Liang Zhao
Keyword(s):  
Cross Sections ◽  
Liquid Jets ◽  
Liquid Jet ◽  
Mixing Process ◽  
Gas Mixing ◽  
Air Blast ◽  
Content Type ◽  
Injection Angle ◽  
The Cross ◽  
Atomization Performance

Purpose The purpose of this study is to investigate the effect of the injection angle α on the spray structures of an air-blast atomizer and help enhance the understanding of droplet-gas mixing process in such atomizers in the engineering domain. Design/methodology/approach The phenomena in the air-blast atomizer were numerically modelled using the computational fluid dynamics software Fluent 17.2. The Euler-Lagrange approach was applied to model the droplet tracking and droplet-gas interaction in studied cases. The standard k-ε model was used to simulate the turbulent flow. A model with a modified drag coefficient was used to consider the effects of the bending of the liquid column and its penetration in the primary breakup region. The Kelvin-Helmholtz, Rayleigh-Taylor model was applied to consider the secondary breakup of the droplets. Findings The basic spatial distribution and spray structures of the droplets corresponding to the angled liquid jet (α = 60°) were similar to those reported in liquid jets injected transversely into a gaseous crossflow studies. The injection angle α did not considerably influence the averaged Sauter to mean diameter (SMD) of the cross-sections. However, the spray structures pertaining to α = 30°, α = 60° and α = 90° were considerably different. In the case of the atomizer with multiple injections, a “collision region” was observed at α = 60° and characterized by a higher ci and larger averaged SMD in the central parts of the cross-sections. Originality/value The injection angle α is a key design parameter for air-blast atomizers. The findings of this study can help enhance the understanding of the droplet-gas mixing process in air-blast atomizers. Engineers who design air-blast atomizers and face new challenges in the process can refer to the presented findings to obtain the desired atomization performance. The code has been validated and can be used in the engineering design process of the gas-liquid jet atomizer.

Cross Sections for Depolarization of 62P3/2 Cesium Atoms Induced in Collision with Noble Gases from D2 Optical Pumping

1980 ◽  
Vol 35 (11) ◽  
pp. 1245-1248
Author(s):  
P. Rudedcki
Keyword(s):  
Energy Transfer ◽  
Cross Sections ◽  
Optical Pumping ◽  
Noble Gases ◽  
Circularly Polarized ◽  
Alkali Atoms ◽  
The Cross ◽  
Cesium Atoms

Abstract Possibilities of examing the relaxation of alkali atoms in 62P3/2 state by analysing the pumping process with a weak circularly polarized D2 line are presented. Results of an experiment on Cs-He and Cs-Ne systems have also been given. Assuming the J-randomization model for relaxation of alkali atoms in 2P3/2 state and neglecting energy transfer between 62PJ states, we obtained the cross sections for relaxation: Cs-He, 62.6 ± 10.0; Cs-Ne, 54.0 ± 9.0; in 10-16 cm2 units.

The cross sections for different channels in heavy ion nuclear reactions

1971 ◽  
Vol 32 (1) ◽  
pp. 7-9 ◽  
Author(s):  
J. Galin ◽  
D. Guerreau ◽  
M. Lefort ◽  
X. Tarrago
Keyword(s):  
Cross Sections ◽  
Nuclear Reactions ◽  
Heavy Ion ◽  
The Cross

Experimental Studies Of Multilayer Glass Structures On Compression, Compression With Bending And Simple Bending

2019 ◽  
pp. 22-30
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Applied Load ◽  
Experimental Studies ◽  
Strength Properties ◽  
Research Topic ◽  
Normative Values ◽  
Laminated Glass ◽  
The Cross ◽  
Experimental Values

The work of multilayer glass structures for central and eccentric compression and bending are considered. The substantiation of the chosen research topic is made. The description and features of laminated glass for the structures investigated, their characteristics are presented. The analysis of the results obtained when testing for compression, compression with bending, simple bending of models of columns, beams, samples of laminated glass was made. Overview of the types and nature of destruction of the models are presented, diagrams of material operation are constructed, average values of the resistance of the cross-sections of samples are obtained, the table of destructive loads is generated. The need for development of a set of rules and guidelines for the design of glass structures, including laminated glass, for bearing elements, as well as standards for testing, rules for assessing the strength, stiffness, crack resistance and methods for determining the strength of control samples is emphasized. It is established that the strength properties of glass depend on the type of applied load and vary widely, and significantly lower than the corresponding normative values of the strength of heat-strengthened glass. The effect of the connecting polymeric material and manufacturing technology of laminated glass on the strength of the structure is also shown. The experimental values of the elastic modulus are different in different directions of the cross section and in the direction perpendicular to the glass layers are two times less than along the glass layers.

Spectroscopy Fundamentals

2017 ◽  
Author(s):  
Kelly Chance ◽  
Randall V. Martin
Keyword(s):  
Vibrational Spectroscopy ◽  
Cross Sections ◽  
Nuclear Spin ◽  
Electronic Spectroscopy ◽  
Rotational Spectroscopy ◽  
Absorption Cross ◽  
Transfer Processes ◽  
Atmospheric Spectroscopy ◽  
Quantitative Spectroscopy ◽  
Broad Overview

This chapter provides a broad overview of the spectroscopic principles required in order to perform quantitative spectroscopy of atmospheres. It couples the details of atmospheric spectroscopy with the radiative transfer processes and also with the assessment of rotational, vibrational, and electronic spectroscopic measurements of atmospheres. The principles apply from line-resolved measurements (chiefly microwave through infrared) through ultraviolet and visible measurements employing absorption cross sections developed from individual transitions. The chapter introduces Einstein coefficients before in turn discussing rotational spectroscopy, vibrational spectroscopy, nuclear spin, and electronic spectroscopy.

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