Nuclear g Factors in 55Fe

1973 ◽  
Vol 51 (7) ◽  
pp. 707-712 ◽  
Author(s):  
P. G. Kerr ◽  
A. W. Gibb ◽  
J. A. Cameron
Keyword(s):  
Excited States ◽  
Gamma Rays ◽  
Target Material ◽  
Internal Field ◽  
Angular Distributions ◽  
Mixing Ratios ◽  
Decay Gamma ◽  
G Factors

The (α,n) reaction on natural chromium has been used to study levels in 55Fe up to 2.5 MeV excitation. Intensities and angular distributions of the decay gamma rays were measured, yielding branching and E2/M1 mixing ratios. In a magnetized target of the alloy Cr20Fe80, the rotation of the angular distributions was observed. Using recently determined lifetimes for the excited states and the average internal field of 277 kOe measured in the target material by Mössbauer absorption, the following g factors are obtained:[Formula: see text]

An Investigation of Odd Parity States in 32S

1974 ◽  
Vol 52 (11) ◽  
pp. 950-958 ◽  
Author(s):  
H. Grawe ◽  
J. E. Cairns ◽  
M. W. Greene ◽  
J. A. Kuehner
Keyword(s):  
Shell Model ◽  
Excited States ◽  
Linear Polarization ◽  
Doppler Shift ◽  
Polarization Measurement ◽  
Angular Distributions ◽  
Resonance States ◽  
Mixing Ratios ◽  
Model Predictions

States in 32S have been populated using the 31P(p,γ) reaction at the Ep = 895, 1438, and 1583 keV resonances. Angular distributions, a linear polarization measurement, and the results from the 32S(α,α′) reaction at 180° yielded the following spin and/or parity assignments for bound levels Jπ(6.62) = 4−, Jπ(6.76) = 3−, 4+, 5−, Jπ(6.85) = 3−, 4+, and Jπ(7.95) = 3, 4, 5−, and for resonance states J(10.26) = 4 and J(10.40) = 4. The γ decay of selected excited states has been studied and mixing ratios were obtained for the strongest branches. Doppler shift measurements yielded lifetimes of 810 (−250, +350) fs, > 300 fs and 110 (−40, +60) fs for the states at 6.62, 6.76, and 7.95 MeV respectively. The results are discussed and compared with shell model predictions.

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.

LIFETIME MEASUREMENTS OF EXCITED STATES IN 73As

2004 ◽  
Vol 13 (05) ◽  
pp. 1019-1034 ◽  
Author(s):  
K. P. SINGH ◽  
T. KAKAVAND ◽  
M. HAJIVALIEI
Keyword(s):  
Statistical Theory ◽  
Excited States ◽  
Doppler Shift ◽  
Nuclear Reactions ◽  
Angular Distributions ◽  
Excitation Energies ◽  
Lifetime Measurements ◽  
Mixing Ratios ◽  
Doppler Shift Attenuation ◽  
First Time

The excited states of 73 As have been investigated via the 73 Ge ( p , n γ)73 As reaction with proton beam energies from 2.5–4.3 MeV. The lifetimes of the levels at 769.6, 860.5, 1177.8, 1188.7, 1274.9, 1344.1, 1557.1 and 1975.2 keV excitation energies have been measured for the first time using the Doppler shift attenuation method. 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 eight γ-transitions have been newly measured.

scholarly journals Measurement of Angular Distributions of \(\gamma \)-rays from 139La+n to Excited States of 140La

2021 ◽  
Author(s):  
Takuya Okudaira ◽  
Shunsuke Endo ◽  
Hiroyuki Fujioka ◽  
Katsuya Hirota ◽  
Kohei Ishizaki ◽  
...  
Keyword(s):  
Excited States ◽  
Gamma Rays ◽  
Angular Distributions

Excited States in 53Mn by the 53Cr(p,nγ)53Mn Reaction

1973 ◽  
Vol 51 (17) ◽  
pp. 1840-1849 ◽  
Author(s):  
Woon-Hyuk Chung ◽  
D. M. Sheppard ◽  
W. C. Olsen ◽  
B. C. Robertson
Keyword(s):  
Statistical Model ◽  
Excited States ◽  
Energy Levels ◽  
Branching Ratios ◽  
Angular Distributions ◽  
Reaction Energy ◽  
Yield Curves ◽  
Mixing Ratios ◽  
Doppler Shift Attenuation ◽  
Γ Ray

The properties of the low-lying excited states in 53Mn were studied by measuring γ-ray angular distributions and lifetimes using the 53Cr(p,nγ)53Mn reaction. Energy levels of 53Mn have been found at 0.378, 1.288, 1.440, 1.619, 2.272, 2.405, 2.572, 2.670, 2.687, 2.705, 2.872, 2.876, 2.914, 2.947, 3.005, 3.095, 3.125, 3.183, 3.193, and 3.250 MeV. The measurement of γ-ray angular distributions and yield curves together with predictions based on the compound nuclear statistical model have enabled spin assignments to be made to the following excited states in 53Mn: 1.440 MeV (11/2), 1.619 MeV (9/2), 2.572 MeV (7/2), 2.687 MeV (7/2), 2.947 MeV (9/2), 3.005 MeV (5/2). Multipole mixing ratios and branching ratios were determined for some of the observed transitions. Lifetimes of nine excited states in 53Mn have been measured using the Doppler-shift attenuation method.

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.

A Study of Levels in 25Mg via the 22Ne(α, nγ)25Mg Reaction

1972 ◽  
Vol 50 (13) ◽  
pp. 1539-1553 ◽  
Author(s):  
D. C. Kean ◽  
R. W. Ollerhead
Keyword(s):  
Gamma Rays ◽  
Ground State ◽  
Branching Ratios ◽  
Angular Distributions ◽  
Rotational Model ◽  
Mixing Ratios ◽  
Decay Properties ◽  
Decay Branch ◽  
Band Mixing ◽  
Good Agreement

Levels in the nucleus 25Mg have been studied by measurement of the angular distributions and polarization of gamma rays from the 22Ne(α, nγ)25Mg reaction. Information regarding spins, parities, mixing ratios, and branching ratios has been obtained for the levels between 2.7 and 4.7 MeV excitation. Spin and parity assignments of 5/2+ and 7/2− have been made to the levels at 3.90 and 3.97 MeV. Mixing ratios have been determined or restricted for most of the observed transitions. The decay branch of the 3.40 MeV level to the ground state is found to be considerably stronger than previously reported, bringing the decay properties of this level into good agreement with the predictions of the simple rotational model. The significance of the results within the framework of the rotational model is discussed. There is evidence for considerable band mixing in levels belonging to the second Kπ = 1/2+ and the Kπ = 1/2− bands.

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.

THE MEASUREMENT AND ANALYSIS OF TRIPLE CORRELATIONS

1964 ◽  
Vol 42 (6) ◽  
pp. 1101-1115 ◽  
Author(s):  
Philip B. Smith
Keyword(s):  
Gamma Rays ◽  
Heavy Particle ◽  
Original Data ◽  
Population Parameters ◽  
True Solution ◽  
Error Matrix ◽  
Mixing Ratios ◽  
Triple Correlation ◽  
Measurement And Analysis

The measurement and analysis of the intensity–direction correlation of gamma rays emitted in cascade following heavy-particle capture are treated. A procedure is discussed which is based upon the expansion of the triple-correlation intensity in terms of the set of angular functions orthogonal over the space of the emission (or absorption) directions. This is in contrast to the usual method which expresses the correlation in terms of Legendre polynomials. In the analysis procedure proposed, the population parameters are found directly from the original data, with the gamma-radiation mixing ratios assigned. The least-squares equations representing the best fit to the data contain the population parameters linearly and are solved by a standard computer program which also gives the value of χ2. The true solution is then found by varying the mixing ratios until a minimum in χ2 is reached. In addition to the determination of the population parameters of the decaying state and the mixing ratios of the gamma rays in the cascade, the calculation of the error matrix of these quantities, and the calculation of the formation parameters in simple capture, are described.

Nuclear g factors of three levels of 192Pt

1969 ◽  
Vol 47 (21) ◽  
pp. 2395-2399 ◽  
Author(s):  
D. B. Kenyon ◽  
L. Keszthelyi ◽  
J. A. Cameron
Keyword(s):  
Hyperfine Field ◽  
Angular Correlation ◽  
Iron Alloy ◽  
Scintillation Detectors ◽  
Angular Correlations ◽  
Mixing Ratios ◽  
G Factors

The g factors of the 316, 612, and 785 keV levels of 192Pt have been measured using gamma–gamma angular correlations perturbed by the hyperfine field in an iron alloy. Sources were 192Ir in 1 at.% Ir Fe alloy. Coincidences were observed using a combination of Ge(Li) and scintillation detectors. For the three levels, the g factors obtained were[Formula: see text]In addition, the E2/M1 mixing ratios were obtained from the angular correlation measurements.[Formula: see text]

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