High-Spin States in 23Na

1973 ◽  
Vol 51 (11) ◽  
pp. 1155-1169 ◽  
Author(s):  
G. G. Frank ◽  
R. V. Elliott ◽  
R. H. Spear ◽  
J. A. Kuehner
Keyword(s):  
Ground State ◽  
Branching Ratios ◽  
Angular Distributions ◽  
Spin States ◽  
High Spin States ◽  
Doppler Shift Attenuation ◽  
Nilsson Model ◽  
Γ Rays ◽  
Band Mixing ◽  
Γ Ray

The 12C(12C,pγ)23Na reaction has been used to study the γ-ray deexcitation of levels up to Ex = 10.4 MeV in 23Na. Doppler-shift attenuation measurements yielded mean lifetimes or lifetime limits for 22 levels. Branching ratios were obtained for the 5.54, 6.11, 6.24, and 6.35 MeV levels and the major modes of decay were observed for 7 levels above Ex = 7 MeV. Angular distributions were measured for γ rays in coincidence with proton groups corresponding to the 5.54, 6.11, 6.24, 6.35, 9.04, and 10.35 MeV levels. The 6.35 MeV level is assigned a spin and parity of 9/2− and interpreted as a member of the low-lying Kπ = 1/2− band in 23Na. Levels at 9.04 and 10.35 MeV are interpreted as the 15/2+ and 13/2− members of the ground-state rotational band and Kπ = 1/2− band, respectively. The experimental γ-ray transition strengths in 23Na are compared to those predicted by the Nilsson model including band mixing. The M1 strengths are modified to account for the effects of isospin.

scholarly journals High Spin States in 193Hg

2020 ◽  
Vol 4 ◽  
pp. 170
Author(s):  
N. Fotiades ◽  
Et al.
Keyword(s):  
Excited States ◽  
High Spin ◽  
Normal Level ◽  
Beam Energy ◽  
Spin Structure ◽  
Spin States ◽  
Tandem Accelerator ◽  
High Spin States ◽  
Γ Rays ◽  
Γ Ray

The high-spin structure of 193Hg was investigated by in-beam γ-ray spectro­scopic techniques. The tandem accelerator at Daresbury Laboratory, U. K., was used to populate excited states of 193Hg through the reaction 150Nd(48Ca,5n)193Hg at a beam energy of 213 MeV and the EUROGAM detector array was used to de­ tect the γ-rays emitted by the deexciting nuclei. The normal level scheme has been further extended and a new band has been observed. In addition two new ΔI=1 structures of competing dipole and quadrupole transitions were found which will be discussed in detail.

Levels in 148Tb excited by the (6,7Li,xn) and (10B,xn) reactions

1979 ◽  
Vol 57 (3) ◽  
pp. 358-367 ◽  
Author(s):  
N. C. Singhal ◽  
M. W. Johns
Keyword(s):  
High Spin ◽  
Internal Conversion ◽  
Gamma Ray ◽  
Angular Distributions ◽  
Spin States ◽  
High Spin States ◽  
Internal Conversion Coefficients ◽  
Conversion Coefficients ◽  
Γ Ray ◽  
Coincidence Measurements

High spin slates in 148Tb have been excited by means of 144Sm(6Li,2n), 144Sm(7Li,3n), and 142Nd(10B,4n) reactions and studied by γ-ray and electron measurements. Gamma-ray singles, excitation functions, angular distributions, internal conversion coefficients, and γ–γ coincidence measurements have been made. A seven-fold gamma–gamma cascade feeding the 9+ isomeric state in 148Tb and originating in a level 4137 keV above that state is strongly excited. The spin and parity assignments are made on the basis of angular distribution and internal conversion coefficients. On the basis of these measurements, the 1006 keV transition is E3 in character; the half-life of the 1006 keV (12−) level is established to be 25 ± 2 ns.These experiments also confirm the existence of a number of high spin states in 148Gd seen by earlier workers.

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.

Quasiparticle Driving Effect on Shape of 87Nb Soft Nucleus

1997 ◽  
Vol 06 (01) ◽  
pp. 177-189 ◽  
Author(s):  
S. Wen ◽  
H. Zheng ◽  
L. K. Zhang ◽  
S. G. Li ◽  
P. K. Weng ◽  
...  
Keyword(s):  
Excitation Energy ◽  
High Spin ◽  
Beam Energy ◽  
Nuclear Shape ◽  
Angular Distributions ◽  
Spin States ◽  
Excitation Functions ◽  
High Spin States ◽  
Γ Rays

The high spin states of 87 Nb have been studied by using the 58 Ni (32 S , 3p)87 Nb reaction at beam energy 95–105 MeV and the reaction 58 Ni (35 Cl , 2pα) at 124 MeV. γ-γ coincidence relations, angular distributions of γ-rays, excitation functions and DCO ratios were measured. High spin states in 87 Nb have been established up to spin of 37/2ℏ and excitation energy of 7 MeV. CSM calculation was carried out with parameters of configuration dependence of nuclear shape. The nature and configuration of every band in 87 Nb are discussed.

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.

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.

LIFETIME MEASUREMENTS OF STATES IN O18 AND Ne22

1964 ◽  
Vol 42 (6) ◽  
pp. 1311-1323 ◽  
Author(s):  
M. A. Eswaran ◽  
C. Broude
Keyword(s):  
Excited State ◽  
Ground State ◽  
Doppler Shift ◽  
State Transition ◽  
Branching Ratios ◽  
Ground State Transition ◽  
Lifetime Measurements ◽  
Doppler Shift Attenuation ◽  
First Excited State ◽  
Doppler Shift Attenuation Method

Lifetime measurements have been made by the Doppler-shift attenuation method for the 1.98-, 3.63-, 3.92-, and 4.45-Mev states in O18 and the 1.28-, 3.34-, and 4.47-Mev states in Ne22, excited by the reactions Li7(C12, pγ)O18 and Li7(O16, pγ)Ne22. Branching ratios have also been measured. The results are tabulated.[Formula: see text]The decay of the 3.92-Mev state in O18 is 93.5% to the 1.98-Mev state and 6.5% to the ground state and of the 4.45-Mev state 74% to the 3.63-Mev state, 26% to the 1.98-Mev state, and less than 2% to the ground state. In Ne22, the ground-state transition from the 4.47-Mev state is less than 2% of the decay to the first excited state.

TESSA : A multi-detector γ-ray array designed to study high spin states

1983 ◽  
Vol 409 ◽  
pp. 343-351 ◽  
Author(s):  
P.J. Twin ◽  
P.J. Nolan ◽  
R. Aryaeinejad ◽  
D.J.G. Love ◽  
A.H. Nelson ◽  
...  
Keyword(s):  
High Spin ◽  
Spin States ◽  
High Spin States ◽  
Γ Ray

The 12 C(γ, 3α) reaction energy levels of 8 Be and 12 C

1955 ◽  
Vol 228 (1174) ◽  
pp. 376-396 ◽  
Keyword(s):  
Ground State ◽  
Energy Levels ◽  
Electric Quadrupole ◽  
Angular Distributions ◽  
Reaction Energy ◽  
Reaction Proceeds ◽  
Γ Ray ◽  
Relationship Of ◽  
The Relationship ◽  
Α Particles

The mechanism of the 12 C(γ, 3α) reaction, for γ-ray energies, E γ , up to about 40 MeV, has been determined from a study of over 2500 stars in nuclear emulsions. The study includes investigation of the angular distributions and correlations of the α-particles. The reaction is initiated mainly by electric-dipole and electric-quadrupole γ-ray interaction, the former being unexpectedly strong when E γ < 20 MeV. For E γ < 25 MeV the reaction proceeds mainly by transitions to the ground-state of 8 Be (spin J = 0), and to 2⋅95 ± 0⋅10 MeV ( J = 2) and 4⋅0 ± 0⋅1 MeV ( J = 2 or 4) levels of 8 Be. Transitions to levels near 6, 10 and 15 MeV (all J = 0, 2 or 4) become predominant when 25 MeV ≤ E γ <26 MeV. For E γ ≥ 26 MeV, most transitions lead to 16⋅8 ± 0⋅2 MeV ( J = 2) and 17⋅6 ± 0⋅2 MeV ( J = 2, possibly 0) levels, and possibly to a further 16⋅4 ± 0⋅2 MeV ( J = 0 or 2) level, levels which have not been detected in other reactions. The reaction mechanism is interpreted in terms of competing modes of decay of a compound nucleus, demonstrating the strong influence of the isotopic spins ( T ) of the levels of 12 C and 8 Be involved. For example, the 2 + levels of 12 C involved when 16 MeV ≤ E γ <20 MeV are (unexpectedly) found to have T = 1, and the 16⋅8 and 17⋅6 MeV levels of 8 Be are also found to have T = 1. The relationship of the 12 C (γ, 3α) reaction to other 12 C photodisintegration reactions (including some new reactions established during the present experiments) is discussed.

High spin states in 96Tc populated through the (α,n) reaction

1980 ◽  
Vol 58 (2) ◽  
pp. 174-190 ◽  
Author(s):  
H. A. Mach ◽  
M. W. Johns ◽  
J. V. Thompson
Keyword(s):  
Theoretical Model ◽  
High Spin ◽  
Spin Structure ◽  
Gamma Ray ◽  
Angular Distributions ◽  
Spin States ◽  
High Spin States ◽  
Gamma Coincidence ◽  
Electron Conversion ◽  
Conversion Coefficients

High spin states of 96Tc populated by the (α,n) reaction using alpha beams from 13 to 27 MeV have been studied. Gamma-ray energies and intensities, gamma–gamma coincidence probabilities, gamma-ray angular distributions, and electron conversion coefficients were determined at 18 MeV. In addition, some results taken at 14 MeV are reported.The high spin structure observed in this work includes the following levels: 49.3(6+), 318.8(6+), 574.7(7+), 926.9(9+), 946.5(8+), 1062.1(8+), 1138.8(8+), 1447.2(9+), 1702.8(10+), 1861.6(9+), 1922.3(11+), 2147.5(11+), 2213.5(10(+)), 2317.2(12+), 2396.8(11(+)), 2599.0((13)+), 2642.4((14)+), and 3020.1(12(+)).These experiments also clarify and extend the information obtained by previous workers. In particular, evidence is adduced for low-lying states at 0.0(7+), 34.3(4+), 45.3(5+), 120.3(3−), 177.0(5+), 226.2(2−), 227.0(4+), and 254.3(3+).The work identifies many other states of intermediate energy.Attenuation coefficients for states in 96Tc are calculated using a theoretical model.

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