Gamma-Ray Linear Polarization and Angular Distribution Formulas in Terms of Phase-Defined Reduced Matrix Elements

1971 ◽  
Vol 49 (3) ◽  
pp. 328-351 ◽  
Author(s):  
P. Taras
Keyword(s):  
Angular Distribution ◽  
Linear Polarization ◽  
Gamma Ray ◽  
Polarization Measurement ◽  
Recent Measurement ◽  
Full Potential ◽  
Matrix Elements ◽  
Mixing Ratios ◽  
Nuclear Models

Gamma-ray linear polarization and angular distribution formulas are presented in terms of the phase-defined reduced matrix elements of Rose and Brink. In particular, the mixing ratios are phase consistently related to reduced matrix elements of interaction multipole operators which are also well defined in phase. The mixing ratios extracted from the measurements of gamma-ray angular distribution and linear polarization can then be compared in both magnitude and sign with the predictions of nuclear models. The full potential of a gamma-ray linear polarization measurement is demonstrated by the discussion of a recent measurement.

Positive-Parity Bands in 29Si

1971 ◽  
Vol 49 (10) ◽  
pp. 1263-1274 ◽  
Author(s):  
A. A. Pilt ◽  
R. H. Spear ◽  
R. V. Elliott ◽  
J. A. Kuehner
Keyword(s):  
Angular Distribution ◽  
Excited State ◽  
Linear Polarization ◽  
Ground State ◽  
Gamma Ray ◽  
Positive Parity ◽  
Rotational Bands ◽  
Mixing Ratios ◽  
First Excited State ◽  
Nilsson Model

A study has been made of several high spin members of the ground state (Kπ = 1/2+) and first-excited state (Kπ = 3/2+) rotational bands in the presumed oblate nucleus 29Si. Gamma-ray angular distribution and linear polarization measurements have confirmed the spin and parity of the 4081 keV level to be 7/2+, and levels at 4742 and 5283 keV have been shown to have Jπ = 9/2+ and (7/2+, 3/2+) respectively. Branching and mixing ratios for the transitions from these states have also been determined; in conjunction with previously measured lifetimes, transition strengths are calculated. The results are compared with the predictions of a Nilsson-model calculation including the effects of coriolis mixing of the low-lying positive parity bands.

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.

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.

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.

Propriétés des niveaux de l'37Ar entre 2.7 et 3.8 MeV d'énergie d'excitation

1975 ◽  
Vol 53 (22) ◽  
pp. 2534-2543 ◽  
Author(s):  
R. Vaillancourt ◽  
B. Haas ◽  
P. Taras
Keyword(s):  
Angular Distribution ◽  
Excitation Energy ◽  
Linear Polarization ◽  
Simultaneous Measurement ◽  
Beam Axis ◽  
Spin Parity ◽  
Mixing Ratios ◽  
Γ Rays

The properties of seven levels in 37Ar were studied via the 34S(α,n)37Ar reaction at Eα = 10.5 MeV. The simultaneous measurement of the linear polarization and the angular distribution of the decay γ rays, in coincidence with the neutrons emitted along the beam axis, provided values of the branching and mixing ratios of these γ rays. From these measurements the spin–parity values for the following levels were established, excitation energy in keV: Ex(Jπ) = 2797(5/2+), 3170(5/2+), 3185(9/2−), 3274(5/2−), 3527(7/2−), 3605(3/2+), 3706(7/2−). The Jπ values of the 3706 keV level are in disagreement with the results of Gadeken et al.

Gamma-ray linear polarization measurement on oriented nuclei

1985 ◽  
Vol 22 (1-4) ◽  
pp. 355-361 ◽  
Author(s):  
J. Rikovska ◽  
N. J. Stone ◽  
V. R. Green
Keyword(s):  
Linear Polarization ◽  
Gamma Ray ◽  
Polarization Measurement

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.

scholarly journals Studying collective nuclear excitations with fast neutrons: a comparison of 76Ge and 76Se

2018 ◽  
Vol 178 ◽  
pp. 02008
Author(s):  
Steven W. Yates ◽  
Sharmistha Mukhopadhyay ◽  
Benjamin P. Crider ◽  
Erin E. Peters
Keyword(s):  
Angular Distribution ◽  
Excitation Function ◽  
Gamma Ray ◽  
Fast Neutrons ◽  
Band Structures ◽  
Mixing Ratios ◽  
Spin Level ◽  
Γ Ray ◽  
Nuclear Excitations

The low-lying, low-spin level structures of 76Ge and 76Se were studied with the (n,n'γ) reaction. Gamma-ray excitation function and angular distribution measurements were performed, and level spins, level lifetimes, γ-ray intensities, and multipole mixing ratios were determined. Large observed B(E2) values support the identification of low-lying band structures.

Sign in / Sign up

Export Citation Format

Share Document