Quantum defect orbital calculations on the alkaline-earth elements: oscillator strengths and photoionization cross sections

1985 ◽  
Vol 63 (11) ◽  
pp. 1441-1445 ◽  
Author(s):  
Carmen Barrientos ◽  
Inmaculada Martin
Keyword(s):  
Cross Sections ◽  
Alkaline Earth ◽  
Experimental Results ◽  
Quantum Defect ◽  
Oscillator Strengths ◽  
Alkaline Earth Elements ◽  
Experimental Values

The quantum defect orbital (QDO) formalism is applied to the computation of oscillator strengths of Mg, Ca, Sr, and Ba and photoionization cross sections of Mg and Ca. For [Formula: see text] transitions, QDO oscillator strengths reproduce fairly well the experimental values both in magnitude and trend. Photoionization cross sections for ns2 → nsεp transitions agree well with experimental results where no autoionization resonances are present. The results of both sets of calculations are at least comparable in quality to those of other more complex procedures.

scholarly journals The Electron Impact Ionization Cross Sections of Methanol, Ethanol and 1-Propanol

Atoms ◽  
2019 ◽  
Vol 7 (3) ◽  
pp. 60 ◽  
Author(s):  
Yogesh Kumar ◽  
Manoj Kumar ◽  
Sachin Kumar ◽  
Rajeev Kumar
Keyword(s):  
Electron Impact ◽  
Cross Sections ◽  
Impact Ionization ◽  
Experimental Results ◽  
Oscillator Strengths ◽  
Ionization Cross ◽  
Total Ionization ◽  
Plane Wave Born Approximation ◽  
Ionization Cross Sections ◽  
Good Agreement

In the present investigation, the plane-wave Born approximation was employed to calculate the total ionization cross sections by electron impact of methanol, ethanol and 1-propanol from the threshold of ionization to 10 MeV. This method requires continuum generalized oscillator strengths (CGOSs). The two different semi-phenomenological expressions of CGOS, given by Mayol and Salvat and Weizsacker and Williams, along with approximated form of the continuum optical oscillator strength (COOS) by Khare et al. were used. Furthermore, the average of the above two CGOSs was also used. The calculated ionization cross sections were compared to the available previous theoretical results and experimental data. Out of three CGOSs, the present results with the average CGOS were found in good agreement with the available experimental results for all the considered molecules. Collision parameters CRP were also calculated from 0.1 to 100 MeV and the calculations were found to be in excellent agreement with the experimental results of Reike and Prepejchal.

Photon-Induced L-Shell X-Ray Production Cross Sections for Lanthanides at 59.54 keV

2017 ◽  
Vol 890 ◽  
pp. 223-226 ◽  
Author(s):  
Rıdvan Durak ◽  
Ferdi Akman ◽  
Abdulhalik Karabulut
Keyword(s):  
High Resolution ◽  
Cross Sections ◽  
Production Cross ◽  
Theoretical Data ◽  
Experimental Results ◽  
X Rays ◽  
X Ray ◽  
Reflection Geometry ◽  
Experimental Values ◽  
Annular Source

The Ll, Lα and Lβ X-ray production cross sections for Pr, Nd, Sm, Eu, Gd and Tb elements were determined using a reflection geometry. The excitation was performed with a 241Am radioactive annular source and the L X-rays emitted from targets were counted with a high-resolution Si (Li) detector. The experimental values were compared with other available experimental results and theoretical data. An agreement is observed between the measured and other experimental results or theoretical data.

Core-polarization effects in subordinate series of the alkali atoms

1989 ◽  
Vol 67 (10) ◽  
pp. 996-1001 ◽  
Author(s):  
Carmen Barrientos ◽  
Inmaculada Martin
Keyword(s):  
Dipole Moment ◽  
Experimental Results ◽  
Quantum Defect ◽  
Oscillator Strengths ◽  
Transition Operator ◽  
Orbital Method ◽  
Effective Dipole Moment ◽  
Core Polarization ◽  
Polarization Effects ◽  
Alkali Atoms

The quantum defect orbital method, including core-polarization effects through an effective dipole-moment transition operator, has been followed to calculate oscillator strengths involving the sharp and diffuse series in the alkali atoms. Comparisons are made among various theoretical and experimental results and those predicted here. It is shown that the formalism adequately describes transitions in subordinate series of the alkali atoms.

Oscillator strength distribution in the alkaline-earth elements

1988 ◽  
Vol 66 (1) ◽  
pp. 29-33 ◽  
Author(s):  
Carmen Barrientos ◽  
Inmaculada Martin
Keyword(s):  
Oscillator Strength ◽  
Alkaline Earth ◽  
Strength Distribution ◽  
Quantum Defect ◽  
Interference Effects ◽  
Electron Transitions ◽  
Alkaline Earth Elements ◽  
The Continuum

The oscillator strength distribution between the discrete and continuous regions of the spectra of Mg, Ca, Sr, and Ba has been obtained. Computations have been carried out through the Quantum Defect Orbital (QDO) method, with explicit introduction of the two-electron transitions that lead to resonances in the spectra of the last three elements. Interference effects between excitations to autoionizing levels and to the continuum have been ignored.

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.

Systematic calculations of energy levels and transitions rates in Mo XXVIII

2020 ◽  
Vol 75 (8) ◽  
pp. 739-747
Author(s):  
Feng Hu ◽  
Yan Sun ◽  
Maofei Mei
Keyword(s):  
Energy Levels ◽  
Oscillator Strengths ◽  
Atomic Data ◽  
Data Sets ◽  
Electron Systems ◽  
Excitation Energies ◽  
Experimental Values ◽  
Qed Effects ◽  
Hyperfine Structures ◽  
Good Agreement

AbstractComplete and consistent atomic data, including excitation energies, lifetimes, wavelengths, hyperfine structures, Landé gJ-factors and E1, E2, M1, and M2 line strengths, oscillator strengths, transitions rates are reported for the low-lying 41 levels of Mo XXVIII, belonging to the n = 3 states (1s22s22p6)3s23p3, 3s3p4, and 3s23p23d. High-accuracy calculations have been performed as benchmarks in the request for accurate treatments of relativity, electron correlation, and quantum electrodynamic (QED) effects in multi-valence-electron systems. Comparisons are made between the present two data sets, as well as with the experimental results and the experimentally compiled energy values of the National Institute for Standards and Technology wherever available. The calculated values including core-valence correction are found to be in a good agreement with other theoretical and experimental values. The present results are accurate enough for identification and deblending of emission lines involving the n = 3 levels, and are also useful for modeling and diagnosing plasmas.

scholarly journals Experimental study of the $ \gamma p \rightarrow K^{0}\Sigma^{+}$, $ \gamma n \rightarrow K^{0} \Lambda$, and $ \gamma n \rightarrow K^{0} \Sigma^{0}$ reactions at the Mainz Microtron

2019 ◽  
Vol 55 (11) ◽  
Author(s):  
C. S. Akondi ◽  
K. Bantawa ◽  
D. M. Manley ◽  
S. Abt ◽  
P. Achenbach ◽  
...  
Keyword(s):  
Experimental Study ◽  
Cross Sections ◽  
Differential Cross ◽  
Legendre Polynomials ◽  
Neutral Kaon ◽  
Experimental Results ◽  
Differential Cross Sections ◽  
Theoretical Predictions ◽  
Photoproduction Reactions ◽  
Insight Into

Abstract.This work measured $ \mathrm{d}\sigma/\mathrm{d}\Omega$dσ/dΩ for neutral kaon photoproduction reactions from threshold up to a c.m. energy of 1855MeV, focussing specifically on the $ \gamma p\rightarrow K^0\Sigma^+$γp→K0Σ+, $ \gamma n\rightarrow K^0\Lambda$γn→K0Λ, and $ \gamma n\rightarrow K^0 \Sigma^0$γn→K0Σ0 reactions. Our results for $ \gamma n\rightarrow K^0 \Sigma^0$γn→K0Σ0 are the first-ever measurements for that reaction. These data will provide insight into the properties of $ N^{\ast}$N* resonances and, in particular, will lead to an improved knowledge about those states that couple only weakly to the $ \pi N$πN channel. Integrated cross sections were extracted by fitting the differential cross sections for each reaction as a series of Legendre polynomials and our results are compared with prior experimental results and theoretical predictions.

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