The 5/2− Resonance at 850 keV in 15N(α,γ)19F

1972 ◽  
Vol 50 (3) ◽  
pp. 268-277 ◽  
Author(s):  
D. W. O. Rogers ◽  
J. H. Aitken ◽  
A. E. Litherland
Keyword(s):  
Doppler Shift ◽  
Negative Parity ◽  
Resonance Level ◽  
Angular Distributions ◽  
Doppler Shifts ◽  
Doppler Shift Attenuation ◽  
Doppler Shift Attenuation Method ◽  
Weak Resonance

A weak resonance at 850 keV in 15N(α,γ)19F corresponding to a level at 4681 ± 1 keV in 19F has been found. Angular distributions and Doppler shifts have been measured for the primary decays to the 5/2− level at 1.35 MeV (63%), 3/2− level at 1.46 MeV (31%), and the 5/2+ level at 197 keV (6%). A spin of 5/2 has been assigned to the resonance level and negative parity is shown to be very likely. The lifetime of the resonance was measured by the Doppler shift attenuation method to be τ = (15.4 ± 3.0) × 10−15 s or Γ = 42.8 ± 8.5 meV. The measured value of ωγ was 6.0 ± 1.0 meV. These measurements together with previous information on Γγ/Γ imply the observed M1 transition strengths are a factor of 20 weaker than predicted for the 5/2 member of the K = 3/2− band in 19F which has previously been associated with this level.

Study of the Decay of the 3.696 MeV Level in 25Al

1971 ◽  
Vol 49 (4) ◽  
pp. 467-474 ◽  
Author(s):  
G. J. McCallum ◽  
R. J. Sparks ◽  
G. E. Coote ◽  
K. P. Pohl
Keyword(s):  
Doppler Shift ◽  
Gamma Ray ◽  
Branching Ratios ◽  
Angular Distributions ◽  
Doppler Shift Attenuation ◽  
Doppler Shift Attenuation Method

The decay of the 3.696 MeV level in 25Al has been studied by means of the 24Mg(p,γ)25Al reaction at the 1.49 MeV resonance. Gamma-ray branching ratios, direct angular distributions, and lifetimes determined by the Doppler shift attenuation method are reported.

LIFETIMES OF LEVELS IN 71Ge

2002 ◽  
Vol 11 (04) ◽  
pp. 347-358 ◽  
Author(s):  
T. KAKAVAND ◽  
K. P. SINGH
Keyword(s):  
Statistical Theory ◽  
Proton Beam ◽  
Doppler Shift ◽  
Nuclear Reactions ◽  
Angular Distributions ◽  
Excitation Energies ◽  
Mixing Ratios ◽  
Doppler Shift Attenuation ◽  
Doppler Shift Attenuation Method ◽  
First Time

The low-lying states of 71Ge have been studied the via the 71Ga (p,n γ)71Ge reaction using proton beam energies of 2.5–4.3 MeV. The angular distributions have been used to assign the spins and the multipole mixing ratios using statistical theory for compound nuclear reactions. The ambiguity in the spin values for the various levels has been removed. The multipole mixing ratios for a few γ-transitions have been newly measured. The lifetimes of the levels at 747.0, 808.0, 831.1, 1377.8, 1406.6, 1414.4, 1422.1, 1558.8 and 1566.1 keV excitation energies have been measured for the first time using the Doppler shift attenuation method.

Transition rates in 29P

1970 ◽  
Vol 48 (22) ◽  
pp. 2683-2691 ◽  
Author(s):  
C. F. Monahan ◽  
H. C. Evans ◽  
J. H. Montague ◽  
W. R. Paulson ◽  
W. M. Zuk
Keyword(s):  
Excited States ◽  
Gamma Rays ◽  
Doppler Shift ◽  
Resonance Level ◽  
Transition Rates ◽  
Mixing Ratios ◽  
Doppler Shift Attenuation ◽  
The Mean ◽  
Doppler Shift Attenuation Method ◽  
Mean Lifetimes

Lifetimes of three of the low-lying excited states in 29P, populated in the 28Si(p,γ) reaction, have been determined using the Doppler shift attenuation method. The mean lifetimes of states at 4.085, 1.956, and 1.385 MeV were found to be 15 ± 4, 370 ± 80, and 200 ± 60 fs.Angular distribution measurements have also been performed on gamma rays resulting from the decay of the 4.085 MeV resonance level. The decay was found to go via states at 3.107 MeV (3%), 1.956 MeV (54%), and 1.385 MeV (43%). The spin of the resonance level was uniquely assigned as 7/2 and the multipole mixing ratios of the 2.129 and 1.385 MeV transitions as + 0.17 ± 0.05 and + 0.303 ± 0.050 respectively. The consequent transition rates indicate that the parity of the resonance level is positive.

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.

Measurement of the 21+ level lifetime in Sn120 by the Doppler shift attenuation method: Evidence of enhanced collectivity

2019 ◽  
Vol 100 (3) ◽  
Author(s):  
A. Kundu ◽  
S. Santra ◽  
A. Pal ◽  
D. Chattopadhyay ◽  
R. Raut ◽  
...  
Keyword(s):  
Doppler Shift ◽  
Level Lifetime ◽  
Doppler Shift Attenuation ◽  
Method Evidence ◽  
Doppler Shift Attenuation Method

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

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.

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
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