Multipole Deformations in 19F and in the Neon Isotopes and Electric Multipole Strength in 19F from Inelastic Scattering of 30 MeV Protons

1974 ◽  
Vol 52 (23) ◽  
pp. 2422-2435 ◽  
Author(s):  
R. De Swiniarski ◽  
A. Genoux-Lubain ◽  
G. Bagieu ◽  
J. F. Cavaignac

Cross sections were measured for inelastic scattering of 30 MeV protons from 19F, 20Ne, 21Ne, and22Ne. The cross sections of the ground state rotational band in these nuclei were analyzed in the coupled channels formalism and yield further evidence for a large hexadecapole deformation in 19F (β4 = 0.14 ± 0.04) and in 20Ne (β4 = 0.28 ± 0.05) in good agreement with several recent proton inelastic scattering experiments. These calculations show also that the Y4 moment is small or close to zero in 21Ne and 22Ne (β4 ≤ 0.05). The analysis of the available 19F cross section in the DWBA formalism shows evidence for a large and significant octupole transition strength for the 1.35 MeV (5/2−) (3.6 W.u.), the 5.43 MeV (7/2−) state (6.70 W.u.), and the 5.63 MeV (5/2−) state (3.60 W.u.). The measured transition strengths are generally in disagreement with recent low energy (α, α′) or (d, d′) results but also with the earlier Coulomb excitation measurements. Thus, we confirm that a major discrepancy still exists between inelastic scattering and Coulomb excitation of the octupole transition strength to several states in 19F but mainly to the 1.35 MeV (5/2−) state as was already pointed out some time ago from a low energy inelastic proton scattering experiment. On a mesuré les sections efficaces pour la diffusion inélastique de protons de 30 MeV excitant les noyaux 19F, 20Ne, 21Ne et 22Ne.

2018 ◽  
Vol 27 (05) ◽  
pp. 1850042
Author(s):  
N. Burtebayev ◽  
A. Duisebayev ◽  
B. A. Duisebayev ◽  
T. Zholdybayev ◽  
Marzhan Nassurlla ◽  
...  

Differential cross-sections for the elastic and inelastic scattering of [Formula: see text]-particles had been measured at the energy of 48.8[Formula: see text]MeV with excitation of low-lying states of the [Formula: see text] nucleus. The data for transitions to the ground [Formula: see text] and excited [Formula: see text], [Formula: see text] states relating to the ground state band were analyzed in the framework of the optical model and the coupled-channel method based on the rotational model. It is shown that the analysis is sensitive not only to the magnitude, but also to the sign of the quadrupole and hexadecapole deformations. The extracted values of the parameters [Formula: see text] and [Formula: see text] are in good agreement with the results of other experiments on the scattering of protons, [Formula: see text] and [Formula: see text]-particles and correspond to the data known from the electron scattering and Coulomb excitation.


2009 ◽  
Vol 24 (11) ◽  
pp. 2191-2197 ◽  
Author(s):  
T. MATSUMOTO ◽  
T. EGAMI ◽  
K. OGATA ◽  
Y. ISERI ◽  
M. KAMIMURA ◽  
...  

We present analyses of breakup effects of 6 He on the elastic scattering by the continuum-discretized coupled-channels method, in which the reaction system is described as a four-body model, n+n+4 He +target. In this analysis, three-body breakup continuum of 6 He is discretized by daiagonalizing the internal Hamiltonian of 6 He in a space spanned by the Gaussian basis functions. The calculated elastic cross sections are in good agreement with the experimental data, which shows that nuclear and Coulomb breakup effects are significant.


1973 ◽  
Vol 51 (12) ◽  
pp. 1293-1299 ◽  
Author(s):  
R. de Swiniarski ◽  
H. E. Conzett ◽  
C. R. Lamontagne ◽  
B. Frois ◽  
R. J. Slobodrian

Angular distributions of the analyzing power and cross sections have been measured for the elastic and inelastic scattering of 25.25 MeV protons exciting the K = 0+ ground-state band in 28Si. Good agreement with experiment is obtained in the coupled-channels formalism on the basis of the rotational model with a quadrupole deformation β2 = −0.40 (oblate) and a hexadecapole deformation β4 = +0.15. The calculations show the great sensitivity of the experimental results to both the magnitude and sign of the quadrupole and hexadecapole deformations. Equivalent fits of the data were obtained either by keeping the deformation length of the various deformed terms of the optical potential constant (δ0 = β0R0 = βIRI = βLSRLS) or by increasing the deformation of the spin–orbit optical potential relative to the central potential by a factor of 1.5 (βLS = 1.5βcent).


1979 ◽  
Vol 57 (4) ◽  
pp. 540-549 ◽  
Author(s):  
R. de Swiniarski ◽  
Dinh-Lien Pham ◽  
G. Bagieu ◽  
H. V. Geramb

Analyzing powers and cross sections have been measured for elastic and inelastic scattering of 40 MeV polarized protons from 90Zr and 92Zr. The analysis has been carried out in the DWBA within the framework of the macroscopic and microscopic models. Furthermore, the coupled-channels calculations using the vibrational model and the full Thomas form for the spin–orbit potential give a very good description for both the cross sections and the analyzing powers of the iow-lying2+, 3−, 5−, and 4+ states in 92Zr and the 2+ and 3− in 90Zr. The cross section and analyzing power for the first 2+ state in these nuclei were compared with previous results at 30 and 20.3 MeV, and from this comparison a certain energy dependence of the relative strength of the spin–orbit deformation to the central deformation could be observed. Microscopic model calculations with tensor and spin–orbit components included in the projectile–target real interaction and with an exact treatment of knock-on' exchange have been performed for the 2+ states in these nuclei. An attempt has also been made in order to include the imaginary component in the N–N interaction. For these calculations, rather good agreement was obtained especially for the 2+ state in 92Zr but poor agreement for 90Zr. Finally, valence plus core polarization calculations have also been done and showed a very good agreement between theory and experiment for those 2+ transitions.


1980 ◽  
Vol 33 (3) ◽  
pp. 495 ◽  
Author(s):  
K Amos ◽  
P Nesci ◽  
I Morrison

Distorted wave approximation analyses of the inelastic scattering of 49�5 MeV protons from 24Mg and 28Si are used to compare 2 + transition densities that were obtained from a standard shell model, deformed potential models and an SU(3) model of the low excitation spectroscopy of these nuclei. Analysing power predictions do not reproduce the data adequately, and the discrepancies indicate a deficiency in the prescription for the transition mechanism.


1966 ◽  
Vol 44 (22) ◽  
pp. 2749-2767 ◽  
Author(s):  
M. S. Lafleur ◽  
N. T. Porile ◽  
L. Yaffe

Cross sections were measured for the formation of 7Be in targets bombarded with 85-MeV protons. The variation of these cross sections with the mass and neutron-to-proton ratio of the target was investigated.Cross-section calculations were performed on the assumption that 7Be is emitted from the irradiated target as an evaporated particle. Calculated and measured cross sections were in good agreement for medium and heavy targets (A > 55). The calculation underestimated the production of' 7Be in light targets (27 < A < 55).


1969 ◽  
Vol 47 (24) ◽  
pp. 2763-2777 ◽  
Author(s):  
C. T. Tindle ◽  
E. Vogt

A comparison is made between the R-matrix and S-matrix theories of low-energy compound nucleus resonances for the particular case of two-level interference. The (p,γ) and (p,n) cross sections of 14C for proton energies between 0.7 and 1.5 MeV are analyzed using both theories. The 15N compound nucleus in this region exhibits strong two-level interference. The two theories provide equally good fits to the data, but the parameters describing the compound-nucleus levels are quite different. A general analytic method of relating the two sets of parameters is derived and shown to give good agreement with the results obtained by curve-fitting procedures. Remarks are made concerning the general behavior of the parameters under strong interference conditions and also on the inclusion of many channels into the analysis.


1992 ◽  
Vol 70 (5) ◽  
pp. 305-310 ◽  
Author(s):  
Y. Frongillo ◽  
B. Plenkiewicz ◽  
P. Plenkiewicz ◽  
J.-P. Jay-Gerin

Pseudopotential calculations of phase shifts, differential, total, and momentum-transfer cross sections for electrons elastically scattered from neon atoms are reported in the impact energy range 0–20 eV. The results are found to be in very good agreement with existing experimental and other theoretical data.


Author(s):  
Hongbin Wang ◽  
Gang Jiang

Photoionization (PI) of Ti<sup>9+</sup> ion is investigated by the Dirac R-matrix method. Multi-Configuration Dirac-Fock (MCDF) calculations are performed to construct accurate target functions. Good agreement of energy levels and radiative transition rates indicate the accuracy of target functions. PI cross sections show good consistency between length and velocity forms. The results are consistent with the previous theoretical values in high-energy regions. Partial waves contribution to the total PI cross sections are discussed for the ground and metastable states. Moreover, the PI cross sections are dominated by many resonance structures and affected by the channel coupling effects in low-energy region. In addition to providing data for the Opacity Project TOPbase, the present work promotes plasma simulation and diagnosis.


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