Energy-dependent coherence width of28Si at excitation energies between 22 and 33 MeV

1969 ◽  
Vol 2 (5) ◽  
pp. 209-213 ◽  
Author(s):  
J. D. A. Roeders ◽  
L. W. Put ◽  
A. G. Drentje ◽  
A. van der Woude
Keyword(s):  
Excitation Energies ◽  
Coherence Width ◽  
Energy Dependent

COMMENT ON A FREQUENT ERROR IN CALCULATIONS OF THE Γn/Γf RATIO

2009 ◽  
Vol 18 (04) ◽  
pp. 823-829 ◽  
Author(s):  
K. SIWEK-WILCZYŃSKA ◽  
J. WILCZYŃSKI
Keyword(s):  
Binding Energy ◽  
Cross Sections ◽  
Ground State ◽  
Residual Nucleus ◽  
Heavy Elements ◽  
Shell Effect ◽  
Excitation Energies ◽  
Neutron Binding Energy ◽  
Energy Dependent ◽  
Leading Journals

In the last decade some 20–30 publications in leading journals appeared in which cross sections for production of super-heavy elements are calculated with an erroneous formula for the Γn/Γf ratio. The erroneous treatment of shell structure corrections leads to an energy-dependent fission barrier that is inserted to the expression for the fission width Γf. In this approach the shell effect in the residual nucleus that emitted the neutron is ignored. We give examples of calculations that illustrate the deviations of the erroneous formula from the correct one. The errors reach several orders of magnitude, especially for low excitation energies and those compound nuclei for which large ground-state shell effect exceeds the neutron binding energy.

scholarly journals The nuclear level density parameter

2019 ◽  
Vol 11 (20) ◽  
pp. 35-46
Author(s):  
Rasha S. Ahmed
Keyword(s):  
Level Density ◽  
State Density ◽  
Density Parameter ◽  
Nuclear Level Density ◽  
Excitation Energies ◽  
Nuclear Level ◽  
Level Density Parameter ◽  
Experimental Works ◽  
Experimental Values ◽  
Energy Dependent

The nuclear level density parameter  in non Equi-Spacing Model (NON-ESM), Equi-Spacing Model (ESM) and the Backshifted Energy Dependent Fermi Gas model (BSEDFG) was determined for 106 nuclei; the results are tabulated and compared with the experimental works. It was found that there are no recognizable differences between our results and the experimental -values. The calculated level density parameters have been used in computing the state density as a function of the excitation energies for 58Fe and 246Cm nuclei. The results are in a good agreement with the experimental results from earlier published work.

SIGMAL: A Program for Calculating L-Shell lonization Cross-Sections

1981 ◽  
Vol 39 ◽  
pp. 198-199 ◽  
Author(s):  
R.F. Egerton
Keyword(s):  
Cross Sections ◽  
Fortran Program ◽  
Absorption Data ◽  
X Ray ◽  
Atomic Electrons ◽  
Energy Dependent ◽  
Hydrogenic Model ◽  
Electron Energy Loss ◽  
X Ray Absorption ◽  
Shell Ionization

SIGMAL is a short (∼ 100-line) Fortran program designed to rapidly compute cross-sections for L-shell ionization, particularly the partial crosssections required in quantitative electron energy-loss microanalysis. The program is based on a hydrogenic model, the L1 and L23 subshells being represented by scaled Coulombic wave functions, which allows the generalized oscillator strength (GOS) to be expressed analytically. In this basic form, the model predicts too large a cross-section at energies near to the ionization edge (see Fig. 1), due mainly to the fact that the screening effect of the atomic electrons is assumed constant over the L-shell region. This can be remedied by applying an energy-dependent correction to the GOS or to the effective nuclear charge, resulting in much closer agreement with experimental X-ray absorption data and with more sophisticated calculations (see Fig. 1 ).

Freeze-Fracture Studies of Membranes in Developing Sieve Elements in a Plant Tissue Culture

1980 ◽  
Vol 38 ◽  
pp. 636-637
Author(s):  
R. D. Sjolund ◽  
C. Y. Shih
Keyword(s):  
Plant Tissue ◽  
Cultured Cells ◽  
Freeze Fracture ◽  
Tissue Cultures ◽  
Sieve Elements ◽  
Intact Plants ◽  
Plant Tissue Cultures ◽  
Whole Plants ◽  
Energy Dependent ◽  
Similar Elements

The differentiation of phloem in plant tissue cultures offers a unique opportunity to study the development and structure of sieve elements in a manner that avoids the injury responses associated with the processing of similar elements in intact plants. Short segments of sieve elements formed in tissue cultures can be fixed intact while the longer strands occuring in whole plants must be cut into shorter lengths before processing. While iyuch controversy surrounds the question of phloem function in tissue cultures , sieve elements formed in these cultured cells are structurally similar to those of Intact plants. We are particullarly Interested In the structure of the plasma membrane and the peripheral ER in these cells because of their possible role in the energy-dependent active transport of sucrose into the sieve elements.

Energy Levels and Electromagnetic Transition of 90-94mo Nuclei Using Ibm-1

2020 ◽  
pp. 149-152
Keyword(s):  
Experimental Data ◽  
Transition Probability ◽  
Energy Levels ◽  
Dynamical Symmetry ◽  
Interacting Boson Model ◽  
Excitation Energies ◽  
Electromagnetic Transition ◽  
Boson Model ◽  
Energy States ◽  
Good Agreement

The energy states for the J , b , ɤ bands and electromagnetic transitions B (E2) values for even – even molybdenum 90 – 94 Mo nuclei are calculated in the present work of "the interacting boson model (IBM-1)" . The parameters of the equation of IBM-1 Hamiltonian are determined which yield the best excellent suit the experimental energy states . The positive parity of energy states are obtained by using IBS1. for program for even 90 – 94 Mo isotopes with bosons number 5 , 4 and 5 respectively. The" reduced transition probability B(E2)" of these neuclei are calculated and compared with the experimental data . The ratio of the excitation energies of the 41+ to 21+ states ( R4/2) are also calculated . The calculated and experimental (R4/2) values showed that the 90 – 94 Mo nuclei have the vibrational dynamical symmetry U(5). Good agreement was found from comparison between the calculated energy states and electric quadruple probabilities B(E2) transition of the 90–94Mo isotopes with the experimental data .

Quantum Resonances: Line Profiles and Dynamics

2003 ◽  
Vol 68 (3) ◽  
pp. 529-553 ◽  
Author(s):  
Ivana Paidarová ◽  
Philippe Durand
Keyword(s):  
Hydrogen Atom ◽  
Operator Theory ◽  
Quantum Dynamics ◽  
Line Profiles ◽  
Static Electric Field ◽  
Reversal Effect ◽  
Quantum Resonances ◽  
Energy Dependent ◽  
Effective Hamiltonians

The wave operator theory of quantum dynamics is reviewed and applied to the study of line profiles and to the determination of the dynamics of interacting resonances. Energy-dependent and energy-independent effective Hamiltonians are investigated. The q-reversal effect in spectroscopy is interpreted in terms of interfering Fano profiles. The dynamics of an hydrogen atom subjected to a strong static electric field is revisited.

scholarly journals Deconvolution in Measurements of Muon Neutrino Energy Spectra with IceCube

2019 ◽  
Vol 207 ◽  
pp. 05006
Author(s):  
Tim Ruhe
Keyword(s):  
Neutrino Energy ◽  
Neutrino Telescope ◽  
Muon Neutrino ◽  
Energy Spectra ◽  
Spectral Measurements ◽  
Energy Dependent

As the energy of an incident neutrino cannot be accessed experimentally, muon neutrino energy spectra have to be inferred from energy-dependent observables, using deconvolution algorithms. This paper discusses the challenges associated with the application of deconvolution algorithms and presents two examples of spectral measurements obtained using the IceCube neutrino telescope in the 59- and 79-string configuration.

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