Collective States in 151Sm

1971 ◽  
Vol 49 (24) ◽  
pp. 3166-3173 ◽  
Author(s):  
D. E. Nelson ◽  
D. G. Burke ◽  
W. B. Cook ◽  
J. C. Waddington
Keyword(s):  
Strong Coupling ◽  
Gamma Rays ◽  
Cross Sections ◽  
Rotational Band ◽  
Ground State ◽  
Coulomb Excitation ◽  
Coupling Model ◽  
Deuteron Scattering ◽  
Collective States

Inelastic deuteron scattering experiments with a target of 151Sm have been carried out with bombarding energies of 5 MeV and 12 MeV. The scattered deuterons were analyzed with a magnetic spectrograph and B(E2) values for the states populated were extracted from the ratios of inelastic to elastic cross sections. The gamma rays following Coulomb excitation of 151Sm by 50 MeV 35Cl ions were also studied with Ge(Li) detectors. Levels at 65.8 keV, 168.4 keV, and 295.1 keV were populated with B(E2) values of 0.80 e2(barn)2, 0.15 e2(barn)2, and 0.46 e2(barn)2 respectively. If it is assumed that the strong-coupling model is appropriate and that the level at 65.8 keV is the first excited member of a rotational band based on the I = 5/2 ground state, the measured B(E2) value corresponds to a deformation of β = 0.21. It must be noted, however, that the observed states do not satisfy the properties expected for a well-ordered ground-state rotational band.

Untersuchung der Beschreibungsmöglichkeit des Selen 77 als deformierter Kern

1967 ◽  
Vol 22 (12) ◽  
pp. 2004-2010 ◽  
Author(s):  
Walter Engels
Keyword(s):  
Rare Earth ◽  
Spherical Shell ◽  
Cross Sections ◽  
Magnetic Moment ◽  
Ground State ◽  
Coulomb Excitation ◽  
Transition Probability ◽  
Coupling Model ◽  
Rare Earth Nuclei ◽  
Nilsson Model

Some aspects of Selen 77 are discussed in the framework of the NILSSON model. The magnetic moment of the 248 keV state give hint fore the existence of a quadrupole force. The large quadrupole moment and the large COULOMB excitation- and (d,d′) -cross sections of some levels indicate collective features. The strong coupling model explains very well the ratio of the reduced B (E2) transition probability. The NILSSON model predicts the spin and the parity of the ground state and gives a better description of the lifetime of the 248 keV level than the spherical shell model. The magnetic moment of the ground state and the 248 keV state are explained by means of a spinpolarisation. The agreement of several values of the decoupling constant is fairly good. On the whole the description of Se77 by the NILSSON model appears to be comparable to the modest success of this model in some rare earth nuclei.

Measurement of the reorientation effect in 24Mg

1970 ◽  
Vol 48 (1) ◽  
pp. 35-45 ◽  
Author(s):  
O. Häusser ◽  
B. W. Hooton ◽  
D. Pelte ◽  
T. K. Alexander ◽  
H. C. Evans
Keyword(s):  
Excited State ◽  
Matrix Element ◽  
Quadrupole Moment ◽  
Cross Sections ◽  
Ground State ◽  
Coulomb Excitation ◽  
Rotational Model ◽  
First Excited State ◽  
Scattering Cross Sections ◽  
Static Quadrupole

The reorientation effect in Coulomb excitation with 62 MeV 35Cl projectiles was used to measure the static quadrupole moment of the first excited state in 24Mg. From a comparison of the inelastic scattering cross sections at CM scattering angles of 123.1° and 72.8°, a static quadrupole moment of Q = −0.243 ± 0.035 b was deduced. The E2 matrix element connecting the ground state and first excited state was also measured and corresponds to 20.3 ± 1.4 W.u. for the 2+ → 0+ transition. The results are compared with predictions of the rotational model.

scholarly journals A Study of the 3·00 MeV Level of 27Al via 24Mg(a, p?)27Al

1968 ◽  
Vol 21 (3) ◽  
pp. 405 ◽  
Author(s):  
DC Kean ◽  
RV Elliott ◽  
RH Spear
Keyword(s):  
Strong Coupling ◽  
Cross Sections ◽  
Inelastic Neutron Scattering ◽  
Coupling Model ◽  
Inelastic Neutron ◽  
Angular Distributions ◽  
Nilsson Model ◽  
Scattering Cross Sections ◽  
27Al Reaction ◽  
Unambiguous Assignment

It is at present considered (Thankappan 1966) that the weak-coupling- model is more appropriate to the 27 Al nucleus than the strong-coupling (Nilsson) model, which has been applied with some success to 25Mg, 25Al, and other lighter nuclei in the 2s-1d shell (Gove 1960). Thankappan (1966) has interpreted the low-lying J = ~, ~, ~, ~, and ~ levels as a multiplet formed by the coupling of a IdG/, proton hole to the first excited (2+) state of 28Si. This model is able to fit simultaneously the level positions and many of the ,,-ray transition rates. The proton inelastic scattering cross sections (Crawley and Garvey 1965) are also in better agreement with this model than with the strong-coupling model. The 3�00 MeV level has for some time been regarded as the low-lying J1r = ;+ state predicted by Thankappan's excited-core model, but the experimental evidence is somewhat contradictory. Towle and Gilboy (1962) claimed an unambiguous assignment of J = ~ from inelastic neutron scattering; the ,,-ray correlation results of Lawergren (1964) are consistent with this assignment. Wakatsuki and Kern (1966) used ,,-ray correlation methods to make a firm assignment of J = i, but it is not obvious that the data used to exclude a J = ; assignment were. free of contributions from the 2� 98 MeV level. In addition, those authors made the dubious assumption that the reaction proceeds through an isolated level of the compound nucleus, and the mixing ratio obtained for the 3�00 to 0 transition is inconsistent with a recent lifetime measurement (Broude, Smulders, and Sharpey-Schafer 1967). Sheppard and van dar Leun (1967), using a Ge(Li) ,,-ray spectrometer, have measured gamma.-gamma correlations in the 26Mg(p,'Y'Y)27Al reaction and claim a definite assignment of J =;. Gove et al. (1967a, 1967b) have performed a D.W.B.A. analysis of the angular distributions in the 28Si(d,3He)27Al reaction using a magnetic spectrograph to resolve the 2�98 and 3�00 MeV levels; they conclude that the 3�00 MeV level has J = I or~. This raises the possibility that the 3�00 MeV "level" is, in fact, a doublet, one member of which has J =; and the other, populated in the (d, SHe) reaction, J = I or~.

Coulomb excitation of 35Cl projectiles

1969 ◽  
Vol 47 (10) ◽  
pp. 1065-1075 ◽  
Author(s):  
O. Häusser ◽  
D. Pelte ◽  
T. K. Alexander ◽  
H. C. Evans
Keyword(s):  
Excited States ◽  
Cross Section ◽  
Gamma Rays ◽  
Gamma Ray ◽  
Coulomb Excitation ◽  
Coupling Model ◽  
Absolute Cross Section ◽  
Mixing Ratio ◽  
Lineshape Analysis ◽  
Doppler Shift Attenuation

Coulomb excitation of the first two excited states in 35Cl was studied by bombarding thick foils of 24Mg and carbon with 35Cl ions of energies between 51 and 61 MeV. De-excitation gamma rays were observed in two 40 cm3 Ge(Li) detectors. From absolute cross-section measurements the following B(E2) values were obtained, B(E2, 0 → 1220) = (0.081 ± 0.009) × 10−50 e2 cm4 and B(E2, 0 → 1762) = (1.17 ± 0.09) × 10−50 e2 cm4. The mixing ratio δ(1762 → 0) was measured to be −2.95 ± 0.45 which can be combined with the corresponding B(E2) value to yield τ(1762) = (0.555 ± 0.050) ps. A Doppler shift attenuation method was employed to interpret the observed gamma-ray lineshapes in terms of nuclear lifetimes. The lineshape analysis yielded τ(1220) = (0.16 ± 0.05) ps and confirmed τ(1762) obtained from the absolute cross-section measurements. The results provide evidence that the three lowest states in 35Cl cannot be interpreted by a weak coupling model.

OBSERVATION OF THE SPIN 20 LEVEL IN THE GROUND STATE ROTATIONAL BAND OF 158Dy

1971 ◽  
Vol 32 (C6) ◽  
pp. C6-289-C6-290
Author(s):  
P. THIEBERGER ◽  
A. W. SUNYAR ◽  
P. C. ROGERS ◽  
N. LARK ◽  
O. C. KISTNER ◽  
...  
Keyword(s):  
Rotational Band ◽  
Ground State

scholarly journals Comment on “From Coulomb excitation cross sections to nonresonant astrophysical rates in three-body systems: The Ne17 case”

2020 ◽  
Vol 102 (6) ◽  
Author(s):  
J. Casal ◽  
M. Rodríguez-Gallardo ◽  
J. M. Arias ◽  
E. Garrido ◽  
R. de Diego
Keyword(s):  
Cross Sections ◽  
Coulomb Excitation ◽  
Excitation Cross Sections ◽  
Three Body

Coulomb excitation of rotational states and ground-state quadrupole moment forAm243

1981 ◽  
Vol 24 (6) ◽  
pp. 2723-2726 ◽  
Author(s):  
C. E. Bemis ◽  
F. K. McGowan ◽  
J. L. Ford ◽  
W. T. Milner ◽  
R. L. Robinson ◽  
...  
Keyword(s):  
Quadrupole Moment ◽  
Ground State ◽  
Coulomb Excitation ◽  
Rotational States

scholarly journals On the Appearance of a Cooper Minimum in the Photoionization Cross Sections of the Plasma-Embedded Li Atom

2009 ◽  
Vol 2009 ◽  
pp. 1-5 ◽  
Author(s):  
Satyabrata Sahoo ◽  
Y. K. Ho
Keyword(s):  
Cross Sections ◽  
Ground State ◽  
Debye Screening Length ◽  
Debye Screening ◽  
Screening Length ◽  
Screening Effect ◽  
Plasma Environment ◽  
Plasma Screening ◽  
Debye Plasma

The plasma screening effect is found to uncover a Cooper minimum in the photoionization cross sections from the ground state of the Li atom embedded in Debye plasma environment. The variation of the location of this minimum with Debye screening length is discussed and analyzed in terms of the instability of the ground state.

Photo-Disintegration Cross Sections of Deuterium and Beryllium for the Gamma-Rays of Sodium 24 and Gallium 72

1950 ◽  
Vol 80 (4) ◽  
pp. 637-642 ◽  
Author(s):  
Arthur H. Snell ◽  
E. C. Barker ◽  
R. L. Sternberg
Keyword(s):  
Gamma Rays ◽  
Cross Sections
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