Excitation energies, photoionization cross sections, and asymmetry parameters of the methyl and silyl radicals

The available [Formula: see text]-matrix parametrization of experimental data on the excitation functions for the elastic and inelastic [Formula: see text] scattering at the collision energies up to 3.4[Formula: see text]MeV is used to generate the corresponding partial-wave cross-sections in the states with [Formula: see text]. Thus, obtained data are fitted using the semi-analytic two-channel Jost matrix with a proper analytic structure and some adjustable parameters. Then the spectral points are sought as zeros of the Jost matrix determinant (which correspond to the [Formula: see text]-matrix poles) at complex energies. The correct analytic structure makes it possible to calculate the fitted Jost matrix on any sheet of the Riemann surface whose topology involves not only the square-root but also the logarithmic branching caused by the Coulomb interaction. In this way, two overlapping [Formula: see text] resonances at the excitation energies [Formula: see text] and [Formula: see text][Formula: see text]MeV have been found.

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On the quenching of Gamow–Teller strength

Canadian Journal of Physics ◽

10.1139/p87-081 ◽

1987 ◽

Vol 65 (6) ◽

pp. 574-577 ◽

Cited By ~ 10

Author(s):

J. Rapaport

Keyword(s):

Cross Sections ◽

Wave Functions ◽

Light Nuclei ◽

Final States ◽

Excitation Energies ◽

Intermediate Energies ◽

Quenching Factor ◽

Configuration Mixing ◽

Gamow Teller ◽

Model Strength

The (p, n) reaction at intermediate energies has been used to measure differential cross sections in light nuclei to final states characterized with a ΔJπ = 1+ transfer (Gamow–Teller (GT) states). Experimental ft values for allowed beta-decay transitions in these nuclei are used to normalize the strength of the GT transitions in units of B(GT). This experimental GT strength is compared with predicted shell–model strength. For p-shell nuclei, the calculated excitation energies of the GT strength using Cohen and Kurath wave functions are in general agreement with the empirical GT distribution. Up to an excitation energy of about 20 MeV, the total experimental and calculated GT strengths are used to obtain the quenching factor, QF = Σ B(GT)exp/Σ B(GT)theor. It is found that QF decreases as the shell gets filled-up. The lowest value seems to occur for single-hole nuclei. This decrease may be explained by configuration mixing not specifically included in the calculations.

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X-Ray Fluorescence Cross-Section Measurements in the Energy Range 4-18 keV

Advances in X-ray Analysis ◽

10.1154/s0376030800023326 ◽

1995 ◽

Vol 39 ◽

pp. 845-855

Author(s):

Krassimir N. Stoev ◽

Joseph F. Dlouhy

Keyword(s):

Cross Sections ◽

Transition Probabilities ◽

Weighted Average ◽

Physical Parameters ◽

Emission Rates ◽

Excitation Energies ◽

X Ray ◽

Fluorescence Cross Section ◽

Theoretical Results

K, L and M shell x-ray fluorescence cross sections have been measured for elements 11 ≤, Z ≤, 92 at excitation energies corresponding to weighted average energies of K-lines of Ti-K (4.558 keV), Fe-K (6,480 keV), Ge-K (10.024 keV), Se-K (11.391 keV) and Mo-K (17.805 keV) . The measurements were performed with an energy-dispersive x-ray spectrometer in a vacuum chamber using thin ultra-pure targets. Rh x-ray tube and secondary targets were used for excitation of x-ray radiation. The measured x-ray fluorescence cross-sections have been compared to previously published experimental and theoretical results. Presented data can be used for determination of physical parameters such as photoionization cross-sections, fluorescence yields, x-ray emission rates, Coster-Kronig transition probabilities and jump ratios.

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Measurement of L X-ray fluorescence cross-sections for 74 W at excitation energies 12, 14, 15 and 16.5 keV with synchrotron radiation

Radiation Physics and Chemistry ◽

10.1016/j.radphyschem.2016.10.023 ◽

2017 ◽

Vol 131 ◽

pp. 79-85 ◽

Cited By ~ 2

Author(s):

R. Kumar ◽

A. Rani ◽

R.M. Singh ◽

M.K. Tiwari ◽

A.K. Singh

Keyword(s):

Synchrotron Radiation ◽

Cross Sections ◽

Excitation Energies ◽

X Ray

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Energy dependence of exotic nuclei production cross sections by photofission reaction in GDR range

Canadian Journal of Physics ◽

10.1139/cjp-2015-0634 ◽

2016 ◽

Vol 94 (2) ◽

pp. 243-248 ◽

Cited By ~ 2

Author(s):

Debasis Bhowmick ◽

F.A. Khan ◽

Debasis Atta ◽

D.N. Basu ◽

Alok Chakrabarti

Keyword(s):

Charge Distribution ◽

Cross Sections ◽

Giant Dipole Resonance ◽

Production Cross ◽

Nuclear Excitation ◽

Excitation Energies ◽

Mass Distributions ◽

Gdr Region ◽

Dipole Resonance ◽

Average Photon Energy

Photofission of actinides is studied in the region of nuclear excitation energies that covers the entire giant dipole resonance (GDR) region. The mass distributions of 238U photofission fragments have been explored theoretically for eight different endpoint bremsstrahlung energies from 11.5 to 67.7 MeV, which correspond to average photon energies of 9.09 to 15.90 MeV. Among these energies, 29.1 MeV corresponds to the average photon energy of 13.7 ± 0.3 MeV, which coincides with the GDR peak for 238U photofission. The integrated yield of 238U photofission, as well as charge distribution of photofission products, is calculated and its role in producing nuclei and their neutron-richness is investigated.

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