Lifetime measurements of the six lowest lying levels in 35Cl

1969 ◽  
Vol 47 (12) ◽  
pp. 1295-1306 ◽  
Author(s):  
F. Ingebretsen ◽  
T. K. Alexander ◽  
O. Häusser ◽  
D. Pelte
Keyword(s):  
Gamma Rays ◽  
Doppler Shift ◽  
Gamma Ray ◽  
Level Structure ◽  
Branching Ratios ◽  
Distance Method ◽  
Lifetime Measurements ◽  
Mixing Ratios ◽  
Doppler Shift Attenuation ◽  
Recoil Distance

The energies, gamma-ray branching ratios, and mean nuclear lifetimes of the six lowest lying levels in 35Cl have been measured. Gamma rays following the reaction 32S(α,pγ)35Cl were studied using two Ge(Li) detectors with 15-cm3 and 40-cm3 active volumes respectively. The lifetimes of the five lowest lying levels were measured using the Doppler shift attenuation method, with the results: 1219 keV, [Formula: see text]; 1763 keV, 0.55 ± 0.15 ps; 2646 keV, 0.30 ± 0.09 ps; 2695 keV, <0.03 ps; and 3003 keV, <0.05 ps. The lifetime of the 3163-keV level was measured to be 60 ± 7 ps, using a recoil distance method. The level structure is discussed taking into account known lifetimes, spins, parities, and gamma-ray mixing ratios.

Gamma rays from the 3702 keV level in 25Al

1969 ◽  
Vol 47 (23) ◽  
pp. 2609-2619 ◽  
Author(s):  
N. Anyas-Weiss ◽  
A. E. Litherland
Keyword(s):  
Angular Distribution ◽  
Lower Limit ◽  
Gamma Rays ◽  
Doppler Shift ◽  
Gamma Ray ◽  
Decay Modes ◽  
Mirror Nucleus ◽  
Mixing Ratios ◽  
Doppler Shift Attenuation ◽  
Decay Gamma

The decay modes of the 7/2−, 3702 keV level in 25Al have been studied at the Ep = 1490 keV resonance in the 24Mg(p,γ)25Al reaction. The decay gamma rays were observed using a 25 cm3 Ge(Li) detector. A previously unreported 2% transition from the resonance to the level at 2723 keV has been observed. The angular distribution of this gamma ray admits only a spin of 7/2 for the 2723 keV level. The lifetime of the 2723 keV level was measured with the Doppler shift attenuation method (DSAM) at the 1660 keV resonance and was found to be [Formula: see text]. The lifetime of the 5/2+, 1790 keV level has been measured using the DSAM and has been found to be [Formula: see text]. From Doppler shift measurements a lower limit for the lifetime of the 3/2+, 945 keV level of [Formula: see text] was obtained. From angular distribution measurements at the Ep = 1490 keV resonance, the following multipole mixing ratios have been measured: δ(R → 0) = 0.00 ± 0.02; δ(R → 1790) = −0.02 ± 0.02; δ(R → 2723) = 0.15 ± 0.30; [Formula: see text]; δ(1790 → 945) = −0.15 ± 0.05; δ(945 → 0) = 0.35 ± 0.10 or 1.7 ± 0.2; δ(945 → 451) = −0.15 ± 0.05 or 2.6 ± 0.4. Comparisons with data in the mirror nucleus 25Mg have been made.

Consistency of the recoil-distance method and the Doppler-shift attenuation method for lifetime measurements using titanium as the slowing-down environment

1975 ◽  
Vol 11 (1) ◽  
pp. 280-281 ◽  
Author(s):  
B. Haas ◽  
J. Chevallier ◽  
N. Schulz ◽  
J. Styczen ◽  
M. Toulemonde
Keyword(s):  
Doppler Shift ◽  
Distance Method ◽  
Lifetime Measurements ◽  
Slowing Down ◽  
Doppler Shift Attenuation ◽  
Recoil Distance ◽  
Doppler Shift Attenuation Method

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 IN 134Pr AND CHIRALITY IN NUCLEI

2006 ◽  
Vol 15 (07) ◽  
pp. 1531-1540 ◽  
Author(s):  
D. TONEV ◽  
P. PETKOV ◽  
D. L. BALABANSKI ◽  
G. DE ANGELIS ◽  
A. GADEA ◽  
...  
Keyword(s):  
Doppler Shift ◽  
Transition Probabilities ◽  
Experimental Results ◽  
Lifetime Measurements ◽  
Evaporation Reaction ◽  
Doppler Shift Attenuation ◽  
Recoil Distance ◽  
Reduced Transition Probabilities ◽  
Fusion Evaporation Reaction

Lifetimes of exited states in 134 Pr were measured be means of the recoil distance Doppler-shift and Doppler-shift attenuation techniques. The experiments were performed at IReS, Strasbourg using the EUROBALL IV spectrometer, in conjunction with the inner BGO ball and the Cologne coincidence plunger apparatus. Exited states in 134 Pr were populated in the fusion-evaporation reaction 119 Sn (19 F , 4 n )134 Pr . Reduced transition probabilities in 134 Pr are compared to the predictions of the two quasiparticle+triaxial rotor and interacting boson fermion-fermion models. The experimental results do not support the presence of static chirality in 134 Pr underlying the importance of shape fluctuations. Only within a dynamical context the presence of intrinsic chirality in 134 Pr can be supported.

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.

Lifetimes of Low Lying Levels of 18O, 18Ne

1974 ◽  
Vol 52 (15) ◽  
pp. 1381-1388 ◽  
Author(s):  
A. B. McDonald ◽  
T. K. Alexander ◽  
O. Häusser ◽  
G. J. Costa ◽  
J. S. Forster ◽  
...  
Keyword(s):  
Doppler Shift ◽  
Transition Rates ◽  
Distance Method ◽  
Doppler Shift Attenuation ◽  
Theoretical Predictions ◽  
Γ Rays ◽  
Recoil Distance

The T(16O,p)18O reaction has been employed to measure the lifetimes of the 1.98 MeV 2+ level (τ = 3.35 ± 0.20 ps) and the 3.55 MeV 4+ level (τ = 24.5 ± 3.3 ps) of 18O by the recoil distance method. The lifetime of the 1.89 MeV 2+ level of 18Ne (τ = 0.63 ± 0.13 ps) has been measured by observing the Doppler shift attenuation of γ rays from 18Ne ions recoiling from the 16O(3He,n) reaction into Y and Ta backings. Transition rates in these mirror nuclei are compared with theoretical predictions.

Lifetimes and branching ratios of energy levels of 28Si. I

1969 ◽  
Vol 47 (6) ◽  
pp. 639-649 ◽  
Author(s):  
A. E. Litherland ◽  
P. J. M. Smulders ◽  
T. K. Alexander
Keyword(s):  
Gamma Rays ◽  
Gamma Ray ◽  
Energy Levels ◽  
Ground Level ◽  
Particle Beam ◽  
High Energy ◽  
Branching Ratios ◽  
Alpha Particles ◽  
Doppler Shift Attenuation ◽  
Energy Gamma

The gamma rays from the 25Mg(α,nγ)28Si reaction have been studied using alpha particles with energies ranging from 4.8 to 6.0 MeV. A 25 cm3 Ge(Li) gamma-ray counter was used to observe the complex high energy gamma-ray spectra at angles between 0° and 130° to the alpha-particle beam. Estimates of the nuclear lifetimes of the energy levels excited were obtained from Doppler shift attenuation measurements. The de-excitation branching ratios of the levels were also measured. The existence of a new level in 28Si at 6695 keV was confirmed. The recently reported 3− level at either 6880 keV or 6889 keV was observed and found to be the 6880-keV member of the doublet. The enhancement of the octupole transition to the ground level of 28Si was found to be 13 Weisskopf units.

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.

Mesures de Rapports d'Embranchement et de Vies Moyennes dans 30Si

1972 ◽  
Vol 50 (3) ◽  
pp. 278-286 ◽  
Author(s):  
A. Gallmann ◽  
F. Haas ◽  
M. Toulemonde
Keyword(s):  
Shell Model ◽  
Gamma Rays ◽  
Doppler Shift ◽  
Branching Ratios ◽  
Matrix Elements ◽  
Excitation Energies ◽  
Doppler Shift Attenuation ◽  
Annular Detector ◽  
Γ Rays

Gamma rays from the decay of 30Si levels with excitation energies less than 6.0 MeV have been studied by the 27Al(α, pγ)30Si reaction. The γ rays were detected in a Ge(Li) detector in coincidence with protons observed in an annular detector placed at 180°. Branching ratios and lifetimes have been extracted. The lifetimes have been measured by the Doppler-shift attenuation method.The electromagnetic matrix elements for some of the observed levels were compared with recent many-particle shell model and core-coupling calculations.

scholarly journals Gamma-ray Studies using a Solid Argon Target: Properties of States in 40K and 40Ar

1979 ◽  
Vol 32 (3) ◽  
pp. 195 ◽  
Author(s):  
DJ Beale ◽  
AR Poletti ◽  
JR Southon
Keyword(s):  
Angular Distribution ◽  
Doppler Shift ◽  
Weak Coupling ◽  
Gamma Ray ◽  
Interaction Model ◽  
Substantial Agreement ◽  
Mixing Ratios ◽  
Doppler Shift Attenuation ◽  
Coupling Calculation ◽  
Solid Argon

The Doppler shift attenuation method was used to deduce lifetimes of levels in 40 Ar and 4�K populated by the reactions 40 Ar(p, n)4�K and 40 Ar(p, p')40 Ar. Spins and mixing ratios in 4�K were also deduced from angular distribution measurements. The target used was solid argon at a temperature of 66 K. Substantial agreement with other recent work has been found. The results are interpreted using a weak coupling calculation and a simple t5 function interaction model.

Sign in / Sign up

Export Citation Format

Share Document