Study of the Ep = 1.724 MeV Resonance in the 27Al(p, γ) 28Si Reaction

1971 ◽  
Vol 49 (6) ◽  
pp. 685-703 ◽  
Author(s):  
S. T. Lam ◽  
A. E. Litherland ◽  
R. E. Azuma
Keyword(s):  
Ground State ◽  
Gamma Ray ◽  
Branching Ratios ◽  
Thick Target ◽  
Angular Distributions ◽  
Transition Strength ◽  
Proton Capture ◽  
A Value ◽  
28Si Reaction ◽  
Relative Measurements

The 13.245 MeV level in 28Si has been populated by resonant proton capture at 1.724 MeV in the 27Al(p,γ)28Si reaction. Gamma-ray angular distributions and linear polarizations have been measured respectively with a coaxial and a planar Ge(Li) counter. Branching ratios have been extracted from the angular distributions. Spins have been assigned to the levels of 28Si with the help of the angular distribution and linear polarization results. The spin and parity of the 13.245 and 9.699 MeV levels are most probably 5− with T = 1 and 0 respectively. The assignment Jπ = 4− for the 8.411 MeV level is in agreement with the present data. A spin and parity of 3− for both the 13.245 and 9.699 MeV levels also fits the data but with more adjustable parameters. Arguments are presented to show that these assignments are unlikely. Relative measurements of the gamma-ray yields from a thick target give a value of (7.5 ± 1.5) eV for (2J + 1)ΓγΓp/Γ of the resonance. The M1 transition strength between the 13.245 and the 9.699 MeV levels is then deduced to be (0.7 ± 0.15) W.u. The known properties of the 9.699 MeV level suggest that it may be associated with an E5 oscillation of the ground state of 28Si.

Proton?Capture Gamma Rays from Nitrogen?13

1962 ◽  
Vol 15 (3) ◽  
pp. 443 ◽  
Author(s):  
AW Parker ◽  
GG Shute
Keyword(s):  
Angular Distribution ◽  
Excited State ◽  
Elastic Scattering ◽  
Gamma Rays ◽  
Ground State ◽  
Recent Experiment ◽  
Gamma Ray ◽  
Angular Distributions ◽  
Proton Capture ◽  
Yield Curves

From a recent experiment in this laboratory (Shute et al. 1962) on the elastic scattering of protons from 12C, resonance levels (E13N, J1t) of 13N were obtained at the laboratory bombarding energies (Ep) shown in Table 1. To confirm these results, an investigation of the yield and angular distribution of gamma rays from the reaction 12C(p'YO)13N and 12C(p'Yl)13N was undertaken. Accordingly, the theoretical angular distributions, W(8), for the gamma ray (Yo) to the ground state of 13Na-) and also for the gamma ray (Yl) to the 1st excited state of 13Na+) were evaluated on the assumptions that overlap of levels in 13N is small and lowest order multipoles are involved. As angular distributions are parity insensitive, these were found to be identical for the two gamma rays expected. The simpler of these angular distributions are also shown on the table. The expected angular distributions indicate that 90� is a suitable angle for yield curves.

An isospin-mixed triplet in 44Ti

1980 ◽  
Vol 58 (9) ◽  
pp. 1360-1366 ◽  
Author(s):  
W. R. Dixon ◽  
R. S. Storey ◽  
J. J. Simpson
Keyword(s):  
Experimental Data ◽  
Ground State ◽  
Gamma Ray ◽  
Branching Ratios ◽  
Proton Decay ◽  
The Other ◽  
Angular Distributions ◽  
Matrix Elements ◽  
Quantitative Estimates

Three levels in 44Ti at energies of 9215 ± 2, 9227 ± 2, and 9239 ± 2 keV have been studied in the 40Ca(α,γ) reaction. Gamma-ray branching ratios, angular distributions, and transition strengths have been measured for each level. Proton decay strengths have also been determined. Each level is assigned Jπ = 2+. The level at 9227 keV must be predominantly T = 1 because of its strong M1 decays, while the other two levels are believed to be predominantly T = 0 because of their stronger E2 transitions to the ground state. Treating the three levels as an isospin-mixed triplet gives a consistent interpretation for all the experimental data, and allows quantitative estimates to be made of the amount of isospin mixing and of the magnitude of the isovector matrix elements.

E3 Coulomb excitation of 19F

1969 ◽  
Vol 47 (21) ◽  
pp. 2335-2342 ◽  
Author(s):  
T. K. Alexander ◽  
O. Häusser ◽  
K. W. Allen ◽  
A. E. Litherland
Keyword(s):  
Cross Section ◽  
Ground State ◽  
Gamma Ray ◽  
Excitation Cross Section ◽  
Coulomb Excitation ◽  
Thick Target ◽  
Transition Strength ◽  
Average Value ◽  
Target Yield ◽  
Model Predictions

The E3 matrix element connecting the ground state with the 5/2−, 1346-keV level in 19F has been measured by projectile excitation of a 19F beam and observation of the 1236-keV de-excitation gamma ray in Ge(Li) detectors. The thick-target yield of the 1236-keV gamma ray was 1.6, 6.0, 9.8, and 23 gammas per 1010 projectiles at bombarding energies of 22, 25, 26, and 28 MeV, respectively. The average value of the strength of the E3 transition deduced from these measurements is [Formula: see text] In addition, the E2 Coulomb-excitation cross section of the 1554-keV level was measured and the reduced transition strength of the E2 transition from the 1554-keV level to the ground state was found to be 6.8 ± 0.7 W.u. Comparisons are made with model predictions.

Coulomb excitation of 133Cs with protons

1985 ◽  
Vol 63 (4) ◽  
pp. 483-487 ◽  
Author(s):  
K. P. Singh ◽  
D. C. Tayal ◽  
B. K. Arora ◽  
T. S. Cheema ◽  
H. S. Hans
Keyword(s):  
Angular Distribution ◽  
Gamma Ray ◽  
Transition Probabilities ◽  
Coulomb Excitation ◽  
Spin Assignment ◽  
Thick Target ◽  
Angular Distributions ◽  
Distribution Data ◽  
Mixing Ratios ◽  
Reduced Transition Probabilities

Protons of energy 3.2–4.2 MeV have been used to Coulomb excite the states in 133Cs. The thick-target gamma-ray yields and the angular distributions were measured using a 50 cm3 Ge(Li) detector. The measurements were used to extract the reduced transition probabilities, B (E2) and B(M1), and multipole mixing ratios (δ) for the various transitions. A spin assignment has been made to the 871.8 keV level on the basis of angular distribution data. The results obtained have been compared with those of other authors.

Levels in 45Sc from Radiative Proton Capture in 44Ca

1974 ◽  
Vol 52 (2) ◽  
pp. 131-139 ◽  
Author(s):  
R. L. Schulte ◽  
J. D. King ◽  
H. W. Taylor
Keyword(s):  
Decay Scheme ◽  
Bound States ◽  
Gamma Ray ◽  
Angular Distributions ◽  
Distribution Data ◽  
Excitation Energies ◽  
Proton Capture ◽  
Resonant States ◽  
Γ Rays ◽  
Γ Ray

A total of 22 resonances has been observed in the 44Ca(p,γ)45Sc reaction within the incident proton energy range of 600 to 930 keV. Gamma-ray singles spectra and γ-ray angular distribution data were accumulated for resonances at Ep = 856 and 906 keV. Both of these resonant states have been found to have spin 3/2. The measured angular distributions of primary γ rays from the resonant states have given spin information on the intermediate bound states of 45Sc with excitation energies above 2 MeV. A γ-ray decay scheme has been derived from the γ-ray spectra. The data indicate new levels at 2151.0, 3525.2, 3548.5, 3584.0, and 3714.3 keV.

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.

14.—Ground State Rotational Bands in 158Dy, 160Dy and 162Dy

1972 ◽  
Vol 70 ◽  
pp. 155-163 ◽  
Author(s):  
G. T. Ewan ◽  
G. I. Andersson
Keyword(s):  
Gamma Rays ◽  
Ground State ◽  
Gamma Ray ◽  
Angular Distributions ◽  
Rotational Bands ◽  
Weak Evidence ◽  
Gamma Coincidence ◽  
Inertia Model ◽  
Coincidence Spectra ◽  
Variable Moment

SynopsisLevels in the ground state bands of 158Dy, 160Dy and 162Dy have been populated by (α, 2n) reactions on metallic targets of separated 156Gd, 158Gd and 160Gd isotopes. Two Ge(Li) detectors were used to study singles gamma-ray spectra, gamma-ray angular distributions, gamma-gamma coincidence spectra and relative yields of gamma-rays for bombarding energies from 20 to 27 MeV. Transitions from all levels in the ground state bands up to the 12+ member were identified and the following level energies in keV established: 158Dy: 0 (0+), 99·0 (2+), 317·4 (4+), 637·9 (6+), 1044·1 (8+), 1520·1 (10+) and 2049·4 (12+); 160Dy: 0 (0+), 86·7 (2+), 283·7 (4+), 581·4 (6+), 967·4 (8+), 1429·0 (10+), 1951·7 (12+); 162Dy: 0 (0+), 80·7 (2+), 265·7 (4+), 548·5 (6+), 921·1 (8+), 1374·8 (10+) and 1901·0 (12+). There is weak evidence for the 14+ levels in 158Dy and 160Dy. The level energies are compared with calculated values using the variable moment of inertia model.

Properties of the 2.645, 2.693, 3.001, and 3.162 MeV levels in 35Cl

1970 ◽  
Vol 48 (5) ◽  
pp. 603-615 ◽  
Author(s):  
P. Taras ◽  
J. Matas
Keyword(s):  
Gamma Rays ◽  
Ground State ◽  
Branching Ratios ◽  
Angular Distributions ◽  
Mixing Ratios ◽  
Four Levels

Angular distributions and linear polarizations of the gamma rays emitted in the 35Cl(p, p′γ)35Cl reaction have been measured. Four resonances were investigated at proton energies of 4.24, 4.82, 5.08, and 5.11 MeV. The spin and parity of the levels at 2.645, 2.693, and 3.001 MeV in 35Cl have been deduced to be 7/2+, 3/2+, and 5/2+, respectively, while the spin and parity of the 3.162 MeV level have been confirmed to be 7/2−. The multipolarity mixing ratios of the decay of these four levels to the ground state have been found to be δ(M3/E2) = 0, δ(E2/M1) = +0.26 ± 0.03, δ(E2/M1) = +0.07 ± 0.02, and δ(E3/M2) = −0.25 ± 0.04, respectively. In addition, the branching ratios for the decay of these four levels have been determined.

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