PROPERTIES OF LEVELS AT 6.69 AND 6.88–6.89 MeV IN 28Si

1966 ◽  
Vol 44 (5) ◽  
pp. 1087-1097 ◽  
Author(s):  
R. J. A. Levesque ◽  
R. W. Ollerhead ◽  
E. W. Blackmore ◽  
J. A. Kuehner
Keyword(s):  
Excited State ◽  
Alpha Particle ◽  
Ground State ◽  
State Transition ◽  
Gamma Ray ◽  
The Other ◽  
Ground State Transition ◽  
Angular Correlations ◽  
First Excited State ◽  
Strong Ground

Levels at 6.69, 6.88, and 6.89 MeV were observed in the 16O(16O, α)28Si reaction, and angular correlations were measured for the resulting gamma-ray transitions, using the geometry in which the alpha particle is detected at 0°. The level at 6.69 MeV had not been reported previously and was assigned spin and parity 0+. The doublet of levels at 6.88–6.89 MeV was not resolved in these measurements, but angular correlations of the gamma-ray transitions were possible, using spectrum subtraction techniques. One member of the doublet, previously assigned spin 3, has a strong ground-state transition; the angular correlation for this transition confirms a 3− assignment to this level. The other member of the doublet, which decays almost entirely to the first excited state, could not be assigned a spin on the basis of these measurements. However, taken in conjunction with other measurements, an assignment of 4+ is favored.

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.

THE NEUTRON CAPTURE 7-RAYS FROM POTASSIUM

1953 ◽  
Vol 31 (6) ◽  
pp. 927-931 ◽  
Author(s):  
G. A. Bartholomew ◽  
B. B. Kinsey
Keyword(s):  
Excited State ◽  
Potassium Carbonate ◽  
Ground State ◽  
Neutron Capture ◽  
State Transition ◽  
Ground State Transition ◽  
Γ Rays ◽  
Γ Ray

The capture γ-rays from potassium have been re-examined with greater resolution than was used in previous experiments. The upper end of the spectrum has been carefully studied both with a sample of natural potassium carbonate and with another in which the potassium was enriched in K40. From a comparison of the spectra two γ-rays with energies of 9.39 ± 0.06 and 8.45 ± 0.02 Mev. are assigned to capture by that isotope. The strong γ-ray at 7.757 ± 0.008 Mev. previously ascribed to the ground state transition in K40 is now found to represent a transition to a low-lying excited state in that nucleus.

Coulomb excitation of 24Mg with 35Cl ions

1969 ◽  
Vol 47 (18) ◽  
pp. 1929-1940 ◽  
Author(s):  
D. Pelte ◽  
O. Häusser ◽  
T. K. Alexander ◽  
H. C. Evans
Keyword(s):  
Quadrupole Moment ◽  
Cross Section ◽  
Ground State ◽  
State Transition ◽  
Gamma Ray ◽  
Coulomb Excitation ◽  
Absolute Cross Section ◽  
Ground State Transition ◽  
Section Measurement ◽  
Anisotropy Measurement

The Coulomb excitation of a thick 24Mg target was studied with 35Cl ions of 61, 57, and 52 MeV. The absolute cross section and the anisotropy of the angular distribution of the ground state transition from the 1.369-MeV state in 24Mg was measured, and their dependence on B(E2) and the quadrupole moment, Q, of the 1.369-MeV state was calculated. A B(E2) of 24.5 ± 2.2 Weisskopf units (W.u.) was deduced from the line shape of the 1.369-MeV gamma ray observed with a 40 cm3 Ge(Li) detector. The quadrupole moment determined from the anisotropy measurement was Q = −0.38 ± 0.16 b. From the cross-section measurement, Q = −0.47 ± 0.19 b was obtained using B(E2) = 24.5 ± 2.2 W.u. The dependence of this value of Q on B(E2) is discussed.

GAMMA-RAY ANGULAR CORRELATION MEASUREMENTS IN Ne22

1964 ◽  
Vol 42 (6) ◽  
pp. 1300-1310 ◽  
Author(s):  
C. Broude ◽  
M. A. Eswaran
Keyword(s):  
Excited State ◽  
Angular Correlation ◽  
Gamma Ray ◽  
Amplitude Ratio ◽  
Spin Assignment ◽  
Primary Radiation ◽  
Angular Correlations ◽  
First Excited State

Coincidence gamma-ray angular correlations of the cascade decays from the 3.34- and 4.47-Mev states in Ne22 through the first excited state have been measured. The levels were excited by the reaction F19 (α, p)Ne22. The correlations give an unambiguous spin assignment of 4 to the 3.34-Mev state; the analysis of the correlations from the 4.47-Mev state is not unique, allowing spin 2 or 3. The quadrupole-to-dipole amplitude ratio for the primary radiation is −0.11 ± 0.03 or −1.07 ± 0.10, respectively, for the spin-2 and spin-3 assignments.

NEUTRON CAPTURE GAMMA RAYS FROM FLUORINE, MAGNESIUM, GALLIUM, BROMINE, AND HAFNIUM

1957 ◽  
Vol 35 (12) ◽  
pp. 1361-1379 ◽  
Author(s):  
P. J. Campion ◽  
G. A. Bartholomew
Keyword(s):  
Energy Range ◽  
Gamma Rays ◽  
Ground State ◽  
Neutron Capture ◽  
State Transition ◽  
High Energy ◽  
The Other ◽  
Ground State Transition ◽  
Γ Rays ◽  
Γ Ray

The neutron capture γ-ray spectra of fluorine, magnesium, gallium, bromine, and hafnium have been studied in the energy range above 3 Mev. In fluorine four γ-rays and in magnesium 12 γ-rays have been detected in addition to those previously observed. Most of these new radiations can be assigned to the known level schemes of the product nuclei. The spectrum obtained for each of the other elements is complex with only a few of the high energy γ-rays resolved, and in each case the γ-ray of highest energy is very weak and difficult to distinguish from the background. The most energetic gallium γ-ray at 7.73 ± 0.02 Mev. may be emitted in the direct ground state transition in Ga70 while the 7.879 ± 0.013 Mev. γ-ray from bromine probably corresponds to the ground state transition in Br80. In hafnium none of the observed γ-rays can be identified with a ground state transition in any of the isotopes.

Optical Characterization Of GaAs/Si: Spectral Features in the Excitonic Region

1987 ◽  
Vol 91 ◽  
Author(s):  
S. Zemon ◽  
S. K. Shastry ◽  
C. Jagannath ◽  
P. Norris ◽  
G. Lambert
Keyword(s):  
Excited State ◽  
Ground State ◽  
State Transition ◽  
Optical Characterization ◽  
Spectral Width ◽  
Light Hole ◽  
Spectral Features ◽  
Ground State Transition ◽  
First Time

ABSTRACTUsing 4.2 K selective photoluminescence (PL) excitation and PL excitation spectroscopy, the n = 2 excited state of the light-hole exciton is observed for the first time in GaAs/Si. The excited state is about 3 meV above the ground state, similar to exciton results for GaAs/GaAs. A spectral width of 1.8 meV is observed for the ground state transition, the narrowest yet reported.

THE 6.48-MEV LEVEL OF C11

1963 ◽  
Vol 41 (5) ◽  
pp. 784-792 ◽  
Author(s):  
D. W. Braben ◽  
P. J. Riley ◽  
G. C. Neilson
Keyword(s):  
Excited State ◽  
Ground State ◽  
State Transition ◽  
Time Of Flight ◽  
Coupling Model ◽  
Ground State Transition ◽  
Intermediate Coupling ◽  
Intermediate Coupling Model

The 6.48-Mev level of C11 has been studied by means of the B10(d,nγ)C11 reaction using time-of-flight techniques. The results show that the ratio of the ground-state transition to the cascade via the second excited state of C11 is 8 ± 1:1. Comparison is made with the predictions of the intermediate-coupling model.

scholarly journals STABILITY OF GROUND STATES IN SECTORS AND ITS APPLICATION TO THE WIGNER–WEISSKOPF MODEL

2001 ◽  
Vol 13 (04) ◽  
pp. 513-528 ◽  
Author(s):  
ASAO ARAI ◽  
MASAO HIROKAWA
Keyword(s):  
Excited State ◽  
Scalar Field ◽  
Ground State ◽  
Adjoint Operator ◽  
Ground States ◽  
The Other ◽  
Coupling Constant ◽  
A Value ◽  
First Excited State ◽  
The One

We consider two kinds of stability (under a perturbation) of the ground state of a self-adjoint operator: the one is concerned with the sector to which the ground state belongs and the other is about the uniqueness of the ground state. As an application to the Wigner–Weisskopf model which describes one mode fermion coupled to a quantum scalar field, we prove in the massive case the following: (a) For a value of the coupling constant, the Wigner–Weisskopf model has degenerate ground states; (b) for a value of the coupling constant, the Wigner–Weisskopf model has a first excited state with energy level below the bottom of the essential spectrum. These phenomena are nonperturbative.

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.

Capture Gamma-Ray Spectra for the 59Co(n, γ)60Co Reaction Using Resonance Energy Neutrons

1975 ◽  
Vol 53 (4) ◽  
pp. 351-359 ◽  
Author(s):  
W. V. Prestwich ◽  
A. M. Lopez
Keyword(s):  
Neutron Energy ◽  
Ground State ◽  
State Transition ◽  
Gamma Ray ◽  
Resonance Energy ◽  
High Energy ◽  
Final States ◽  
Ground State Transition ◽  
Energy Distributions ◽  
Direct Capture

Capture gamma-ray spectra for the reaction 59Co(n, γ)60Co were obtained for different neutron energy distributions. Significant contributions from the high energy resonances were observed. Analysis of the data for the ground state transition indicates that the contribution to the process from potential direct capture is substantially smaller than previous estimates. No retardation of transitions to final states exhibiting an ln = 3 (d,p) stripping pattern, such as that observed for 132 eV capture, is evident for the higher energy resonances.

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