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.

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]

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.

SUCCESSIVE DECAYS FROM Pr137 AND Ce137m: DECAY OF ADJACENT PRASEODYMIUM ISOTOPES

1958 ◽  
Vol 36 (11) ◽  
pp. 1487-1508 ◽  
Author(s):  
G. T. Danby ◽  
J. S. Foster ◽  
A. L. Thompson
Keyword(s):  
Excited State ◽  
Small Group ◽  
Electron Capture ◽  
High Spin ◽  
Gamma Rays ◽  
Isomeric State ◽  
Ground State ◽  
Branching Ratios ◽  
Spin States ◽  
High Spin States

The decay of Pr137 entirely to a 9.0-hour ground state of Ce137 was independently discovered. By allowed electron capture, Ce137 decays predominantly to a low-lying state of La137, with only a 3% branching to a 440-kev excited state. The 440-kev transition is at least predominantly E2 in character.A 34.4-hour isomeric state produced by the La139(p, 3n)Ce137m reaction decays by a 254.5-kev M4 transition to the 9-hour -ground state. A 0.6% branching was found from the isomeric state directly to a small group of apparently high spin states in La137.Studies of mass-separated isotopes confirmed the existence of 1.5-hour Pr137 and 1.0-hour Pr136. The K-capture to positron branching ratios observed in the decay of Pr139, Pr138, Pr137, and Pr136 show that these isotopes decay by allowed transitions to their cerium daughters. Characteristic gamma rays were observed.

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.

Level structure of 35Cl from the 32S(α,pγ)35Cl reaction

1970 ◽  
Vol 48 (10) ◽  
pp. 1259-1269 ◽  
Author(s):  
B. W. Hooton ◽  
O. Häusser ◽  
F. Ingebretsen ◽  
T. K. Alexander
Keyword(s):  
Excitation Energy ◽  
Level Structure ◽  
Branching Ratios ◽  
The Other ◽  
Mixing Ratios ◽  
Γ Ray ◽  
Four Levels

Proton–gamma coincidences from the reaction 32S(α,pγ)35Cl at Eα = 10.975, 11.960, and 12.120 MeV have been measured, using method II of Litherland and Ferguson. Twelve previously unreported levels between 3.94 and 6.40 MeV excitation energy have been found. The spins of four levels, 1.763 (5/2), 2.646 (7/2), 3.945 (9/2), and 4.885 (7/2), have been determined. Possible spins have been assigned to 12 of the other levels. Branching ratios and γ-ray multipole mixing ratios for all the levels studied are given.

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.

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.

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.

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