Cross section for the reaction 16O(γ,n0)15O at giant resonance energies

1969 ◽  
Vol 47 (9) ◽  
pp. 1037-1046 ◽  
Author(s):  
T. A. Khan ◽  
J. S. Hewitt ◽  
K. G. McNeill
Keyword(s):  
Differential Cross Section ◽  
Cross Section ◽  
Ground State ◽  
Giant Resonance ◽  
Theoretical Work ◽  
Laboratory System ◽  
Photoneutron Reaction ◽  
Neutron Spectra ◽  
Recent Theoretical Work ◽  
Resonance Energies

The cross section for that photoneutron reaction in 16O which leaves 15O in its ground state has been measured for photon energies ranging from 17 to 30 MeV, i.e. at energies corresponding to giant resonance excitations in 16O. Time-of-flight methods, yielding resolutions equal to 100 keV at a neutron energy of 6 MeV, were used to measure neutron spectra emitted at an angle of 98° when targets of ordinary and heavy water were irradiated with pulsed bremsstrahlung. The differential cross section at 22.3 MeV excitation was found to be 1.00 ±.05 mb/sr, assuming a photodisintegration cross section at 98° equal to 55.3 μb/sr (laboratory system) for deuterium, this latter value having been derived from calculations which have been substantiated experimentally to within ± 10%. The results are discussed with reference to other photodisintegration experiments and to recent theoretical work.

Photoneutron reaction inO17: Ground-state differential cross section at 98°

1979 ◽  
Vol 20 (1) ◽  
pp. 27-37 ◽  
Author(s):  
R. G. Johnson ◽  
B. L. Berman ◽  
K. G. McNeill ◽  
J. G. Woodworth ◽  
J. W. Jury
Keyword(s):  
Differential Cross Section ◽  
Cross Section ◽  
Differential Cross ◽  
Ground State ◽  
Photoneutron Reaction

Absolute differential cross section for the 7Li(3He, ααd) reaction at

1985 ◽  
Vol 63 (11) ◽  
pp. 1438-1440 ◽  
Author(s):  
V. D'Amico ◽  
G. Fazio ◽  
S. Femino ◽  
G. Giardina ◽  
A. Italiano ◽  
...  
Keyword(s):  
Differential Cross Section ◽  
Cross Section ◽  
Differential Cross ◽  
Ground State ◽  
Absolute Differential ◽  
The Absolute

The analysis of the dα bidimensional spectra of the 7Li(3He, ααd) reaction at [Formula: see text] is a suitable way of calculating the absolute differential cross section and estimating the competition among the various (d, 8Be) and (α, 6Li) channels when the ground state, the 3.04-MeV 8Be states, and the 5.65-MeV 6Li state are involved.

PION PRODUCTION DIFFERENTIAL CROSS SECTION OF HEAVY ION COLLISIONS AT SUBTHRESHOLD ENERGIES

1993 ◽  
Vol 08 (26) ◽  
pp. 4667-4678
Author(s):  
K.M. ABUMURAD
Keyword(s):  
Differential Cross Section ◽  
Cross Section ◽  
Differential Cross ◽  
Heavy Ion Collisions ◽  
Pion Production ◽  
Giant Resonance ◽  
Heavy Ion ◽  
Ion Collisions ◽  
Invariant Differential ◽  
Theoretical Results

The Lorentz-invariant differential cross section (LIDCS) for π production in heavy ion collisions was studied through the two-step process, NN→NΔ→NNπ. A phenomenological interaction potential containing central and tensor terms was used. The effect of inclusion of the tensor term on the LIDCS was little. The target nucleus 12C was excited to one of its giant resonance states, Jπ=1+, T=1, while the projectile nucleus 16O was excited to an isobar Δ (M=1232 MeV , ΓΔ=115.11 MeV ) which decayed (NΔ→NNπ), giving a nucleon and a pion mπ=138 MeV . In comparison with available experimental data, the shape was reproduced, but the theoretical results were higher.

Further Evidence of Isospin Splitting in the Giant Resonance of 11B

1974 ◽  
Vol 52 (1) ◽  
pp. 92-94 ◽  
Author(s):  
W. Del Bianco ◽  
P. Boucher ◽  
S. Kundu ◽  
B. Rouben
Keyword(s):  
Differential Cross Section ◽  
Cross Section ◽  
Differential Cross ◽  
Giant Resonance ◽  
Recent Calculation ◽  
Isospin Splitting

The 90° differential cross section of the 9Be(d, γ0)11B reaction has been measured at deuteron energies from 3 to 12 MeV. The results of this experiment are consistent with a recent calculation of the dipole states of mass 11 nuclei, and with measurements of the 11B(γ, nγ′) and 11B(γ, pγ′) processes, and confirm the isospin splitting of the giant resonance in 11B.

Investigation of Fine Structure in the Photoneutron Cross Sections of 16O and 208Pb

1975 ◽  
Vol 53 (15) ◽  
pp. 1434-1442 ◽  
Author(s):  
R. G. Johnson ◽  
J. D. Irish ◽  
K. G. McNeill
Keyword(s):  
Fine Structure ◽  
High Resolution ◽  
Differential Cross Section ◽  
Cross Section ◽  
Cross Sections ◽  
Ground State ◽  
Center Of Mass ◽  
Energy Spectra ◽  
Neutron Time ◽  
Good Agreement

The structure in the photoneutron cross sections of 16O and 208Pb has been studied by the measurement of high resolution photoneutron energy spectra using the neutron time-of-flight technique and bremsstrahlung irradiations. For 16O, the ground state differential cross section at 98° has been deduced between 17.3 and 28.5 MeV and is in good agreement with most previous studies. Fine structure is seen throughout the cross section. Eight neutron energy spectra for 208Pb from bremsstrahlung endpoint energies in the range 11.0 to 15.5 MeV were obtained. Strong peaks are seen at center of mass neutron energies of 1.67, 1.85, 2.06, 2.19, 2.68, 3.15, 3.27, 3.50, 3.77, and 4.03 MeV with weaker peaks elsewhere. The energies of these peaks are in good agreement with previous measurements in this laboratory. The energies of peaks in the spectra are compared with recent cross section measurements.

Ground State Radiation Width of the 10.18 MeV, Jπ = 3−, State in 28Si Deduced From 100 MeV Proton Inelastic Scattering

1974 ◽  
Vol 52 (14) ◽  
pp. 1369-1371
Author(s):  
Y. S. Horowitz
Keyword(s):  
Angular Distribution ◽  
Differential Cross Section ◽  
Cross Section ◽  
Ground State ◽  
Transition Rates ◽  
Cross Section Data ◽  
Section Data ◽  
Proton Inelastic Scattering ◽  
State Radiation ◽  
Mev Protons

Differential cross section data for 100 MeV protons inelastically scattered from 6Li, 9Be, 12C, 24Mg, and 28Si are compared with the corresponding E2 and E3 transition rates and a strong correlation is shown to exist between (dσ/dΩ)max and Γγ0 if the shape of the proton angular distribution is characteristic of single excitation. The persistence of the correlation to transitions with Γγ0/Γγ < 0.1 allows an estimate of Γγ0 = 8.6 ± 5 × 10−4 eV for the 10.18 MeV, Jπ = 3−, level in 28Si.

Ground state photoneutron angular distributions in the giant resonance of 16O

1970 ◽  
Vol 48 (14) ◽  
pp. 1635-1648 ◽  
Author(s):  
J. W. Jury ◽  
J. S. Hewitt ◽  
K. G. McNeill
Keyword(s):  
Cross Section ◽  
Ground State ◽  
Giant Resonance ◽  
Flight Path ◽  
Angular Distributions ◽  
Interference Effects ◽  
Experimental Runs ◽  
High Neutron ◽  
High Neutron Energy ◽  
Short Flight

Photoneutron spectra for transitions to the ground state in the giant resonance of 16O were measured with high neutron energy resolution (ΔE ~ 60 keV) at angles of 50, 66, 82, 98, 114, 130, and 146 degrees relative to the direction of the incident bremsstrahlung beam. The spectra at the various angles were measured during successive experimental runs using a single 50 m time-of-flight spectrometer. The different angles were obtained by bending the electron beam relative to the direction of the flight path. Angular normalization was achieved by using a fast neutron monitor located at the end of a short flight path which was always normal to the reaction plane. Legendre coefficients for the angular distributions were extracted as functions of the excitation energy. From the energy dependence of the coefficients, interference effects are evident in the ground state (γ,n) cross section in the region from 17 to 30 MeV.

π+–p elastic scattering at 47.9 MeV

1979 ◽  
Vol 57 (1) ◽  
pp. 73-78 ◽  
Author(s):  
E. G. Auld ◽  
D. Axen ◽  
J. Beveridge ◽  
C. Duesdieker ◽  
L. Felawka ◽  
...  
Keyword(s):  
Elastic Scattering ◽  
Differential Cross Section ◽  
Cross Section ◽  
Differential Cross ◽  
Phase Shifts ◽  
Laboratory System ◽  
Angular Range ◽  
Three Phase

The differential cross section for π+–p elastic scattering at 47.9 MeV has been measured in the angular range from 30 to 170° in the laboratory system. The three phase shifts extracted from these data, δS3 = −4.7 ± 0.5°, δP31 = −0.53 ± 0.14°, and δP33 = 5.1 ± 0.3°, are consistent with phase shifts obtained at other energies.

The light-scattering Mueller matrices for Rayleigh and Rayleigh-Gans-Debye approximation

1990 ◽  
Vol 55 (12) ◽  
pp. 2889-2897
Author(s):  
Jaroslav Holoubek
Keyword(s):  
Light Scattering ◽  
Theoretical Work ◽  
Matrix Elements ◽  
Elastic Light Scattering ◽  
Yield Information ◽  
Recent Theoretical Work ◽  
Particle Parameters ◽  
Complete Set ◽  
Single Matrix ◽  
Scattering Matrix Elements

Recent theoretical work has shown that the complete set of polarized elastic light-scattering studies should yield information about scatterer structure that has so far hardly been utilized. We present here calculations of angular dependences of light-scattering matrix elements for spheres near the Rayleigh and Rayleigh-Gans-Debye limits. The significance of single matrix elements is documented on examples that show how different matrix elements respond to changes in particle parameters. It appears that in the small-particle limit (Rg/λ < 0.1) we do not loose much information by ignoring "large particle" observables.

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