Gamma-Ray multipole mixing ratios using nuclear orientation:166Er

The 19F(α,nγ)22Na reaction was studied using a Ge(Li) single-crystal polarimeter in addition to conventional Ge(Li) counters to elucidate certain spin, parity, and multipole-mixing ratio assignments to low levels of 22Na. The 1.984 MeV level, which had previously been assigned 2+ or 3+, has been shown not to be 3+ and, while 2+ is favored by the experiment, the evidence tends to suggest a problem in the interpretation of the properties of this level. The 2.572 MeV level is shown most likely to have spin and parity 2+. The J = 2 level at 3.059 MeV is clearly established as having even parity. In several cases limits on mixing ratios are obtained. These results cast doubt on certain model identifications made recently in 22Na.

Download Full-text

Properties of low-lying states in 43Sc

Canadian Journal of Physics ◽

10.1139/p70-340 ◽

1970 ◽

Vol 48 (22) ◽

pp. 2735-2750 ◽

Cited By ~ 20

Author(s):

G. C. Ball ◽

J. S. Forster ◽

F. Ingebretsen ◽

C. F. Monahan

Keyword(s):

Excited States ◽

Gamma Ray ◽

Level Structure ◽

Surface Barrier ◽

Angular Correlations ◽

Mixing Ratios ◽

Gamma Coincidence ◽

Theoretical Predictions ◽

Barrier Detector ◽

Coincidence Spectra

The 40Ca(α, pγ)43Sc reaction at Eα = 11.8 to 15.5 MeV has been used to investigate the level structure of 43Sc below 4.2 MeV excitation. Level energies and decay schemes were determined from proton–gamma coincidence spectra obtained using an annular surface barrier detector positioned near 180° and two 40 cm3 Ge(Li) detectors. Angular correlations were measured in the same configuration using an array of six 12.7 × 15.2 cm NaI(Tl) detectors mounted on the Chalk River LOTUS goniometer. Twelve new levels were observed in 43Sc and information on the spins, branching ratios, and gamma-ray multipole mixing ratios of these and several other excited states has been obtained. The results are compared with recent theoretical predictions of Johnstone. In particular, levels at 1931 and 2552 keV, 1830 keV and 1883 keV have been tentatively assigned as the 9/2+ and probable 11/2+ members of the kπ = 3/2+ band, the (fp)3, Jπ = 11/2− state, and the 9/2− member of the kπ = 3/2− band, respectively.

Download Full-text

Coulomb excitation of low-energy levels in 45Sc

Canadian Journal of Physics ◽

10.1139/p79-167 ◽

1979 ◽

Vol 57 (8) ◽

pp. 1196-1203 ◽

Cited By ~ 5

Author(s):

V. U. Patil ◽

R. G. Kulkarni

Keyword(s):

Gamma Ray ◽

Transition Probabilities ◽

Coulomb Excitation ◽

Energy Levels ◽

Negative Parity ◽

Core Excitation ◽

Mixing Ratios ◽

Reduced Transition Probabilities ◽

Excitation Model ◽

First Time

Low-lying negative parity levels in 45Sc were Coulomb excited with 2.5 to 3.5 MeV protons and 4 to 5 MeV 4He ions to test the weak coupling core-excitation model. A Ge(Li) detector was used to measure the gamma-ray yields. The 543, 976, 1408, and 1662 keV levels in 45Sc were Coulomb excited for the first time. Gamma-ray angular distributions were measured at 3.0 MeV proton energy in deducing multipole mixing ratios and spin values. Energy level measurements (in units of kiloelectronvolts) and spin values obtained are as follows: 976, 5/2, 7/2 and 1408, 7/2. The E2 and M1 reduced transition probabilities were determined for the six states. The 376, 720, 1237, 1408, and 1662 keV levels have properties consistent with the interpretation of coupling a 1f7/2 proton to the first 2+ core state.

Download Full-text

(n,n′γ) studies of 114,116Cd

Canadian Journal of Physics ◽

10.1139/p80-002 ◽

1980 ◽

Vol 58 (1) ◽

pp. 8-15 ◽

Cited By ~ 4

Author(s):

T. M. Newton ◽

J. M. Davidson ◽

W. K. Dawson ◽

P. W. Green ◽

H. R. Hooper ◽

...

Keyword(s):

Gamma Ray ◽

Energy Levels ◽

Angular Distributions ◽

Mixing Ratios

Energy levels below 2.2 MeV excitation in 114,116Cd have been investigated using the (n, n′γ) reaction. Gamma-ray angular distributions were measured, and energy levels, spins, and gamma-ray multipole mixing ratios were deduced. Levels and their spins have been confirmed at 1134 (0), 1210 (2), 1283 (4), 1365 (2), 1733 (4), and 1843 (2) keV for 14Cd and at 1213 (2), 1220 (4), and 1381 (0) keV for 116Cd. New spin assignments have been made for the levels at 1861 (3) and 2049 (3) keV for 114Cd and at 1644 (2,3) and 1917 (3) keV for 116Cd. The states at 1959 keV in 114Cd and 1923 keV in 116Cd are shown to be consistent with assignments of 3.

Download Full-text

AN ILLUSTRATION OF A TYPE OF TRIPLE CORRELATION MEASUREMENT WHICH CAN BE EASILY INTERPRETED

Canadian Journal of Physics ◽

10.1139/p60-100 ◽

1960 ◽

Vol 38 (7) ◽

pp. 927-940 ◽

Cited By ~ 27

Author(s):

A. E. Litherland ◽

G. J. McCallum

Keyword(s):

Angular Correlation ◽

Gamma Rays ◽

Gamma Ray ◽

Residual Nucleus ◽

Incident Beam ◽

Electric Quadrupole ◽

Final States ◽

Angular Correlations ◽

Mixing Ratios ◽

Triple Correlation

The Mg26(He4, nγ)Si29 reaction has been used to illustrate the simplifications introduced in the interpretation of triple angular correlations by choosing a target and bombarding particles of zero spin and by observing the emitted particles, in this case neutrons, in a counter fixed at 0° to the beam. The angular correlations of the gamma rays with respect to the incident beam then depend only upon the properties of the final states in the residual nucleus. The angular correlation of the electric quadrupole 2.03-Mev gamma ray is predicted uniquely by theory and this prediction has been verified experimentally. The angular correlations of the 1.28-Mev and 2.43-Mev gamma rays have yielded for the E2/M1 amplitude mixing ratios +0.25 ± 0.05 or −3.4 ± 0.5 and −0.26 ± 0.08 or −1.10 ± 0.16 respectively. In addition, the experiment provides an illustration of the value of the recently discovered technique of neutron – gamma-ray discrimination in an organic scintillator.

Download Full-text

Nuclear Orientation of 152Eu in Gold

Australian Journal of Physics ◽

10.1071/ph830127 ◽

1983 ◽

Vol 36 (2) ◽

pp. 127 ◽

Cited By ~ 1

Author(s):

PJ Blamey ◽

D Bingham ◽

JA Barclay ◽

JD Cashion

Keyword(s):

Hyperfine Interaction ◽

Angular Correlation ◽

Decay Scheme ◽

Nuclear Orientation ◽

Temperature Range ◽

Mixing Ratios ◽

Gamma Transitions

Nuclear orientation of 152Eu in gold in the temperature range 9 mK-1 K has been used to determine the mixing ratios of a number of gamma transitions and the multipolarities of several beta transitions of the 152Eu decay scheme. The results agree closely with those from y-y and y-p angular correlation measurements where these have been done. Our results on the" hyperfine interaction of 152Eu in gold contradict those previously published.

Download Full-text