The14N(n,n′γ) Cross Section of the 2.313-MeV First Excited State

The concentration and depth profile of Cu and S in patinna samples have been determined by using Nuclear Reaction Analysis (NRA) and Rutherford Backscattering Spectroscopy (RBS). For the NRA the differential cross section was mesaured for the 1327 keV 7-ray deexciting the third excited state to the ground state of 6 3Cu through the reaction 63Cu(p,p'7), as well as, for the 2230 keV γ-ray deexciting the first excited state to the ground state through the resonant reaction 32S(p,p'7). The mesaurements of both excitation functions were performed in the energy range 3.0 - 3.7 MeV in 20 keV steps and at an angle of 125°.

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The first excited state of 9Be

Canadian Journal of Physics ◽

10.1139/p83-175 ◽

1983 ◽

Vol 61 (10) ◽

pp. 1371-1373 ◽

Cited By ~ 20

Author(s):

F. C. Barker

Keyword(s):

Excited State ◽

Cross Section ◽

Reasonable Agreement ◽

R Matrix ◽

First Excited State

An R-matrix fit to recent 9Be(γ,n)8Be cross-section measurements just above the neutron threshold gives parameters that are in reasonable agreement with those obtained from fits to data from other reactions.

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Photoneutron cross sections in 7Li

Canadian Journal of Physics ◽

10.1139/p77-059 ◽

1977 ◽

Vol 55 (5) ◽

pp. 428-433 ◽

Cited By ~ 6

Author(s):

H. Ferdinande ◽

N. K. Sherman ◽

K. H. Lokan ◽

C. K. Ross

Keyword(s):

Fine Structure ◽

Excited State ◽

Cross Section ◽

Cross Sections ◽

Ground State ◽

Reasonable Agreement ◽

Branching Ratio ◽

Energy Spectra ◽

Average Value ◽

First Excited State

Photoneutron energy spectra from 7Li have been measured by time-of-flight methods, for bremsstrahlung end-point energies increasing in 2 MeV steps from 13 to 25 MeV. The ground-state and approximate first-excited-state differential cross sections at 90° have been obtained from 8.5 to 23 MeV. No pronounced fine structure has been observed. The measured branching ratio to the first excited state falls from an average value of 0.70 between 10.3 and 14.5 MeV to an average of 0.29 between 14.5 and 18 MeV, and rises again to an average of 0.38 between 18 and 23 MeV. This behaviour can be explained by a crude theoretical model in which 1p → 2s and 1p → 1d single particle transitions dominate below 18 MeV. The calculation predicts a branching ratio of 0.50 near threshold, falling to 0.23 at higher energies, in reasonable agreement with the experiment. The integrated value of the ground-state cross section up to 23 MeV is about (38.7 ± 3.9) MeV mb, while that for the first excited state is about (17.2 ± 3.4) MeV mb. Together they account for 39% of the exchange-augmented dipole sum of 7Li.

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The 12C(p, g)13N Cross Section near the Ep = 0·46 MeV Peak

Australian Journal of Physics ◽

10.1071/ph920749 ◽

1992 ◽

Vol 45 (6) ◽

pp. 749 ◽

Cited By ~ 2

Author(s):

S Hinds ◽

FC Barker

Keyword(s):

Excited State ◽

Cross Section ◽

Thick Target ◽

R Matrix ◽

Best Value ◽

First Excited State ◽

Target Data

The I2C(p,'Y?3N cross section in the neighbourhood of the Ep = 0�46 MeV peak has been measured using thin and thick targets, and fitted using R-matrix formulae. The best value for the radiation width of the first excited state of I3N is 0�53�0�05 eV. eanalysis of earlier thick-target data gives values consistent with this result.

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Photoneutron Reactions in 18O

Canadian Journal of Physics ◽

10.1139/p75-096 ◽

1975 ◽

Vol 53 (8) ◽

pp. 786-794 ◽

Cited By ~ 13

Author(s):

J. D. Allan ◽

J. W. Jury ◽

R. G. Johnson ◽

K. G. McNeill ◽

J. G. Woodworth ◽

...

Keyword(s):

Excited State ◽

Cross Section ◽

Cross Sections ◽

Differential Cross ◽

Ground State ◽

Energy Spectra ◽

Continuum State ◽

Average Value ◽

First Excited State ◽

Time Of Flight Spectroscopy

Photoneutron energy spectra from 18O have been measured by time-of-flight spectroscopy at bremsstrahlung endpoint energies from 11 to 18 MeV in 1 MeV steps to obtain the (γ, n0) and (γ, n1) differential cross sections. The ground state photoneutron cross section contains at least 8 major resonances in the region from 10 to 17 MeV and has an average value of 100 μb/sr. The cross section to the first excited state of 17O contains only two major resonances, at 11.4 and 14.4 MeV, and the average cross section in the region from 11 to 16 MeV is about 40 μb/sr. Of particular interest is a resonance at 14.4 MeV which appears to reflect a simple excitation of one of the valence neutrons to the 2p3/2 state. Analysis of the (γ, n0) and (γ, n1) cross sections for this continuum state leads to estimates of the configuration amplitudes of the 2s1/2 and 1d5/2 components of this state to be 0.62 ± 0.06 and 0.78 ± 0.08 respectively and the ratio of the (2s1/2)2 to (1d5/2)2 amplitudes in the ground state of 18O to be 0.39 ± 0.02.

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Calculation of the 13N(p, ?)14O Cross Section at Low Energies

Australian Journal of Physics ◽

10.1071/ph850657 ◽

1985 ◽

Vol 38 (5) ◽

pp. 657 ◽

Cited By ~ 15

Author(s):

FC Barker

Keyword(s):

Experimental Data ◽

Excited State ◽

Shell Model ◽

Cross Section ◽

Energy Region ◽

Model Calculations ◽

R Matrix ◽

Considerable Uncertainty ◽

First Excited State ◽

Low Energies

R-matrix formulae are used to calculate the 13N(p, ?) 140 cross section in the energy region of astrophysical interest. Values of the R-matrix parameters are determined by fitting experimental data in 14C and 14N as well as 140, and by making use of shell model calculations where necessary. With the presently available data, there is considerable uncertainty in the predicted cross section, but this could be reduced appreciably by a measurement of the lifetime of the first excited state of 14C. With the preferred channel radius of about 5 fm, the predicted cross section is lower than those found in two previous calculations, which are discussed in some detail.

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