Mesures de vies moyennes dans 12B, 14N et 16O

1970 ◽  
Vol 48 (13) ◽  
pp. 1595-1606 ◽  
Author(s):  
A. Gallmann ◽  
F. Haas ◽  
N. Balaux ◽  
B. Heusch ◽  
M. Toulemonde
Keyword(s):  
Wave Function ◽  
Doppler Shift ◽  
Partial Width ◽  
Transition Energies ◽  
Radiative Transitions ◽  
Upper Limits ◽  
Doppler Shift Attenuation ◽  
Theoretical Predictions ◽  
Doppler Shift Attenuation Method ◽  
Gamma Radiations

Lifetimes of nuclear states have been measured by the Doppler-shift attenuation method. Gamma radiations from the 11B(d,pγ)12B, 19F(p,αγ)16O, and 12C(h,pγ)14N reactions were observed with a Ge(Li) detector at θγ = 7°, 90° and 173°. The following lifetimes were obtained:[Formula: see text]Upper limits have been set for very fast lifetimes, and transition energies were also determined. The partial widths of the radiative transitions from the 6.44 MeV state of 14N were compared with theoretical predictions. The amplitude of a (p3/2)−2 configuration in the wave function of this level was evaluated using the partial width of the 6.44 → 3.95 MeV transition determined in the present work.

scholarly journals A Search for an Excited Kp=0+ Rotational Band in 24Mg

1976 ◽  
Vol 29 (3) ◽  
pp. 139 ◽  
Author(s):  
D Branford ◽  
LE Carlson ◽  
FCP Huang ◽  
N Gardner ◽  
TR Ophel ◽  
...  
Keyword(s):  
Shell Model ◽  
Quadrupole Moment ◽  
Rotational Band ◽  
Doppler Shift ◽  
Transition Rates ◽  
Model Calculations ◽  
Doppler Shift Attenuation ◽  
Doppler Shift Attenuation Method ◽  
Absolute Transition ◽  
Good Agreement

A search is described for an excited Kn = 0+ rotational band based on the 6� 44 MeV level of 24Mg. Mean nuclear lifetimes have been measured by the Doppler shift attenuation method using the 12C('60,a)24Mg reaction and the results are 't'm = 66�29, 28�7 and 13�3 fs for levels at 6'44, 8�65 and 10� 58 MeV respectively. The absolute transition rates found for the y decays from the 6�44 and 8�65 MeV levels are in good agreement with the results of shell model calculations if it is assumed that these levels are the 0+ and 2 + members respectively of the excited Kn = 0+ rotational band. Based on this assumption, a result Qoo = 0�48 �0�08b is obtained for the intraband quadrupole moment. From a study of the 23Na(p, y) reaction, it is established that the J = 4 levels at 12� 63 and 13�05 MeV do not decay by enhanced E2 transitions to the 8� 65 MeV level. This suggests that neither of these levels is the 4 + member of the excited Kn = 0+ rotational band. An assignment of J" = 4+ is made to one member of the doublet at 10�58 MeV.

LIFETIME MEASUREMENTS OF STATES IN O18 AND Ne22

1964 ◽  
Vol 42 (6) ◽  
pp. 1311-1323 ◽  
Author(s):  
M. A. Eswaran ◽  
C. Broude
Keyword(s):  
Excited State ◽  
Ground State ◽  
Doppler Shift ◽  
State Transition ◽  
Branching Ratios ◽  
Ground State Transition ◽  
Lifetime Measurements ◽  
Doppler Shift Attenuation ◽  
First Excited State ◽  
Doppler Shift Attenuation Method

Lifetime measurements have been made by the Doppler-shift attenuation method for the 1.98-, 3.63-, 3.92-, and 4.45-Mev states in O18 and the 1.28-, 3.34-, and 4.47-Mev states in Ne22, excited by the reactions Li7(C12, pγ)O18 and Li7(O16, pγ)Ne22. Branching ratios have also been measured. The results are tabulated.[Formula: see text]The decay of the 3.92-Mev state in O18 is 93.5% to the 1.98-Mev state and 6.5% to the ground state and of the 4.45-Mev state 74% to the 3.63-Mev state, 26% to the 1.98-Mev state, and less than 2% to the ground state. In Ne22, the ground-state transition from the 4.47-Mev state is less than 2% of the decay to the first excited state.

Lifetime measurements by the Doppler-shift attenuation method in theSn115(α,nγ)Te118reaction

2011 ◽  
Vol 83 (5) ◽  
Author(s):  
C. Mihai ◽  
A. A. Pasternak ◽  
S. Pascu ◽  
D. Filipescu ◽  
M. Ivaşcu ◽  
...  
Keyword(s):  
Doppler Shift ◽  
Lifetime Measurements ◽  
Doppler Shift Attenuation ◽  
Doppler Shift Attenuation Method

Measurement of lifetimes of nuclear excited states by doppler shift attenuation method

1964 ◽  
Vol 8 (1) ◽  
pp. 52-53 ◽  
Author(s):  
M.A. Eswaran ◽  
H.E. Gove ◽  
A.E. Litherland ◽  
C. Broude
Keyword(s):  
Excited States ◽  
Doppler Shift ◽  
Doppler Shift Attenuation ◽  
Doppler Shift Attenuation Method

Lifetimes of Excited Levels in $^{32}$S from the Doppler Shift Attenuation Method

2000 ◽  
Vol 37 (5) ◽  
pp. 512-518 ◽  
Author(s):  
T. K. Yang ◽  
S. T. Park ◽  
B. K. Seo ◽  
H. C. Kim ◽  
D. W. Lee ◽  
...  
Keyword(s):  
Doppler Shift ◽  
Doppler Shift Attenuation ◽  
Doppler Shift Attenuation Method

Lifetimes of States in 29Si, 27Al, and 26Mg

1971 ◽  
Vol 49 (23) ◽  
pp. 2886-2897 ◽  
Author(s):  
A. B. McDonald ◽  
T. K. Alexander ◽  
O. Häusser ◽  
G. T. Ewan
Keyword(s):  
Doppler Shift ◽  
Line Shape ◽  
Coulomb Excitation ◽  
Thick Target ◽  
Distance Method ◽  
Model Predictions ◽  
Doppler Shift Attenuation ◽  
Recoil Distance ◽  
Doppler Shift Attenuation Method

The recoil-distance method was used to measure the lifetimes of the 29Si, 3626 keV (7/2−) level (4.2 ± 0.5 ps) from the 12C(19F,npγ)29Si reaction, the 26Mg, 1809 keV (2+) level (0.7 ± 0.3 ps) from the 12C-(19F,αpγ)26Mg reaction, and the 27Al, 843 keV (1/2+) level (45 ± 6 ps) from the 27Al(35Cl,35Cl)27Al Coulomb excitation reaction. The Doppler shift attenuation method was employed to determine the lifetime of the 27Al, 1013 keV (5/2+) level [Formula: see text] from the line shape for thick target Coulomb excitation by 67 MeV 35Cl. The results are compared with model predictions.

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