Photoneutrons from 20Ne

1975 ◽  
Vol 53 (8) ◽  
pp. 795-801 ◽  
Author(s):  
J. G. Woodworth ◽  
J. W. Jury ◽  
K. H. Lokan ◽  
N. K. Sherman
Keyword(s):  
Excited States ◽  
Cross Section ◽  
Ground State ◽  
Giant Dipole Resonance ◽  
Time Of Flight ◽  
Photon Absorption ◽  
Absolute Cross Section ◽  
Energy Distributions ◽  
Dipole Resonance ◽  
Integrated Cross Section

Photoneutron energy distributions from a target of liquid neon have been measured at 90° by time of flight for bremsstrahlung endpoint energies increasing in 1 MeV steps from 19 to 32 MeV. The differential ground state cross section for the major (91%) isotope 20Ne has been obtained, together with an estimate of the strength of transitions to excited states of 19Ne. Six photoneutron groups are observed, reflecting photon absorption which correlates excellently with existing photoproton data, although the absolute cross section is about 10% smaller.It is noted that the giant dipole resonance, estimated by combining the photoneutron and photoproton data, is centered at approximately 20 MeV, which is anomalously low, and that the integrated cross section up to 28 MeV exhausts only half of the dipole sum.

Photoneutrons from 19F

1976 ◽  
Vol 54 (11) ◽  
pp. 1178-1189 ◽  
Author(s):  
N. K. Sherman ◽  
K. H. Lokan ◽  
R. W. Gellie
Keyword(s):  
Excited States ◽  
Cross Section ◽  
Electric Dipole ◽  
Ground State ◽  
Time Of Flight ◽  
Branching Ratios ◽  
Integrated Cross Section ◽  
Time Of Flight Method

The 19F(γ,n) reaction was studied by irradiating teflon with bremsstrahlung of energy increasing from 13 MeV to 21 MeV in 1 MeV steps. Photoneutron spectra were measured by the time-of-flight method. Excited states of 19F at 12.10, 12.38, 13.82, and 16.24 MeV were observed. The total integrated cross section between 11.9 and 17.9 MeV was found to be (14.4 ± 2.2) MeV mb. Branching ratios to the first group of excited states of 18F compared to the ground state were measured, along with resonance widths and approximate radiative widths. They are consistent with the interpretation that all four states arise from electric dipole d → f valence transitions, with the first two states having Jπ = 1/2−, and the second two having 3/2−.

Photoneutron Cross Sections in 14N

1972 ◽  
Vol 50 (15) ◽  
pp. 1689-1696 ◽  
Author(s):  
R. W. Gellie ◽  
K. H. Lokan ◽  
N. K. Sherman ◽  
R. G. Johnson ◽  
J. I. Lodge
Keyword(s):  
Excited States ◽  
Cross Section ◽  
Cross Sections ◽  
Neutron Emission ◽  
Giant Resonance ◽  
Sequential Decay ◽  
Dipole Resonance ◽  
Intermediate States ◽  
Integrated Cross Section ◽  
High Degree

Photoneutron distributions from 14N have been obtained by time-of-flight methods, for bremsstrahlung end-point energies increasing in 2 MeV steps from 15.5 to 29.5 MeV. A large part of the neutron yield is associated with the sequential decay of 14N to 12C, through well-defined intermediate states of 13C, at 7.55, 8.86, and 11.80 MeV, which are unstable against neutron emission. The (γ,n0) cross section for neutron emission to the ground state of 13N is found to agree very closely with the corresponding (γ,p0) cross section, implying a high degree of isospin purity for the giant dipole resonance of 14N. It is observed that the decay of the giant resonance proceeds freely through those odd-parity excited states of the A = 13 nuclei which are single hole states formed by the removal of a p-shell nucleon from the parent 14N.The integrated cross section for all neutron-producing interactions is found to be 88 ± 5 MeV mb.

Fine structure in the photoneutron spectra from praseodymium-141 and lead

1970 ◽  
Vol 48 (8) ◽  
pp. 950-953 ◽  
Author(s):  
K. G. McNeill ◽  
J. W. Jury ◽  
J. S. Hewitt
Keyword(s):  
Fine Structure ◽  
Excited State ◽  
Energy Spectrum ◽  
Cross Section ◽  
Ground State ◽  
Giant Dipole Resonance ◽  
Daughter Nucleus ◽  
State Transitions ◽  
Dipole Resonance ◽  
Section Curve

Careful measurements of the energy spectrum of photoneutrons ejected from praseodymium and from natural lead show that there are peaks on top of the expected smooth spectrum. Comparison with the recent cross-section studies, which indicate structure on the giant dipole resonance for these nuclei, shows agreement between the energies of the peaks found in the present work and the energies En = E−Qi where E corresponds to a peak in the cross-section curve and Qi is the threshold for producing a given state in the daughter nucleus. Only ground state transitions (for Pr) or ground state and the first two excited state transitions (for Pb) need be invoked.

Charge Transfer Between CO22+ and Ar or Ne at Collision Energies 3-10 eV

2003 ◽  
Vol 68 (1) ◽  
pp. 178-188 ◽  
Author(s):  
Libor Mrázek ◽  
Ján Žabka ◽  
Zdeněk Dolejšek ◽  
Zdeněk Herman
Keyword(s):  
Charge Transfer ◽  
Excited States ◽  
Ground State ◽  
Scattering Method ◽  
Translational Energy ◽  
Centre Of Mass ◽  
Energy Distributions ◽  
Zener Model ◽  
Beam Scattering ◽  
Product Ions

The beam scattering method was used to investigate non-dissociative single-electron charge transfer between the molecular dication CO22+ and Ar or Ne at several collision energies between 3-10 eV (centre-of-mass, c.m.). Relative translational energy distributions of the product ions showed that in the reaction with Ar the CO2+ product was mainly formed in reactions of the ground state of the dication, CO22+(X3Σg-), leading to the excited states of the product CO2+(A2Πu) and CO2+(B2Σu+). In the reaction with Ne, the largest probability had the process from the reactant dication excited state CO22+(1Σg+) leading to the product ion ground state CO2+(X2Πg). Less probable were processes between the other excited states of the dication CO22+, (1∆g), (1Σu-), (3∆u), also leading to the product ion ground state CO2+(X2Πg). Using the Landau-Zener model of the reaction window, relative populations of the ground and excited states of the dication CO22+ in the reactant beam were roughly estimated as (X3Σg):(1∆g):(1Σg+):(1Σu-):(3∆u) = 1.0:0.6:0.5:0.25:0.25.

Fluorescence anisotropy in indole under two-photon excitation in the spectral range 385–510 nm

2018 ◽  
Vol 20 (30) ◽  
pp. 19922-19931 ◽  
Author(s):  
M. E. Sasin ◽  
A. G. Smolin ◽  
K.-H. Gericke ◽  
E. Tokunaga ◽  
O. S. Vasyutinskii
Keyword(s):  
Propylene Glycol ◽  
Excited States ◽  
Spectral Range ◽  
Ground State ◽  
Fluorescence Anisotropy ◽  
Photon Absorption ◽  
Two Photon Absorption ◽  
Two Photon ◽  
Photon Excitation ◽  
Molecular Ground State

This paper presents the detailed study of two-photon excited fluorescence in indole dissolved in propylene glycol produced by two-photon absorption from the molecular ground state to several high lying excited states.

scholarly journals GDR Contribution to Coulomb Excitation. II. 17O

1982 ◽  
Vol 35 (3) ◽  
pp. 301 ◽  
Author(s):  
FC Barker
Keyword(s):  
Excited State ◽  
Shell Model ◽  
Excited States ◽  
Giant Dipole Resonance ◽  
Coulomb Excitation ◽  
Dipole Resonance ◽  
First Excited State ◽  
Virtual Excitation

The contribution to the Coulomb excitation of the first excited state of 170 due to virtual excitation of the giant dipole resonance (GDR) is calculated, using shell model wavefunctions for the ground and first excited states. A large value is obtained.

scholarly journals Photoionisation Cross Sections of Chlorine Atoms and Molecules at 584 Å

1986 ◽  
Vol 39 (5) ◽  
pp. 779 ◽  
Author(s):  
WJ van der Meer ◽  
RJ Butselaar ◽  
CA de Lange
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Ground State ◽  
Modulation Method ◽  
Absolute Cross Section ◽  
Molecular Chlorine ◽  
Chlorine Atoms ◽  
Atoms And Molecules ◽  
Ionic States ◽  
State Ionic

A recently developed modulation method is used to obtain cross sections for the photoionisation of ground state neutral to ground state ionic, atomic and molecular chlorine relative to that of the HCl + (X2n 1IZ,3IZ) +-- HCl(XI ~ +) transition at the He Ia wavelength. With the known absolute cross section of the latter process, determined by (e,2e) coincidence spectroscopy, the present ell,periments provide absolute photoionisation cross sections of the CI + epz,l,o) +-- Clep) and Cli (XZ n g, 1IZ,3 IZ) +-- Clz (X I ~ t) transitions. Relative cross sections, previously determined for the transitions to the additional Cl and Clz ionic states accessible with He Ia radiation, are used to obtain absolute cross sections for the Cl+(IDz, ISO) +-- Clep) and Cli(AZnu,1IZ,3IZ, BZ~t) +-- Clz(XI~t) ionisation processes.

INCLUSIVE TRITIUM STRIPPING REACTION THEORY

1996 ◽  
Vol 05 (01) ◽  
pp. 107-119 ◽  
Author(s):  
A.I. AKHIEZER ◽  
A.P. SOZNIK ◽  
YU. A. BEREZHNOY
Keyword(s):  
Cross Section ◽  
Transfer Reaction ◽  
Energy Distributions ◽  
Nucleon Transfer ◽  
Intermediate Energies ◽  
Reaction Theory ◽  
Integrated Cross Section

The angular and energy distributions and the integrated cross-section of the inclusive two-nucleon transfer reaction with the participation of three-nucleon nucleus were calculated at intermediate energies.

The 11B(d,γ0)13C reaction in the region of the giant dipole resonance

1981 ◽  
Vol 59 (6) ◽  
pp. 781-783 ◽  
Author(s):  
G. Kajrys ◽  
W. Del Bianco ◽  
J. Kim ◽  
S. Landsberger ◽  
R. Lecomte ◽  
...  
Keyword(s):  
Differential Cross Section ◽  
Cross Section ◽  
Differential Cross ◽  
Giant Dipole Resonance ◽  
Yield Curve ◽  
Plastic Scintillator ◽  
Resonant Structure ◽  
Crystal Spectrometer ◽  
Dipole Resonance ◽  
Γ Rays

The 90° differential cross section of the 11B(d,γ0)13C reaction has been measured at deuteron energies from 1.95 to 12.0 MeV in steps varying from 100 to 200 keV. The γ-rays have been detected by a 23 cm long × 23 cm diameter NaI(Tl) crystal spectrometer enclosed in a plastic scintillator anticoincidence shield. The yield curve shows a resonant structure at the energies Eexe = 20.4 ± 0.1 and 22.0 ± 0.2 MeV.

scholarly journals Constraining the in-medium nucleon-nucleon cross section from the width of nuclear giant dipole resonance

2020 ◽  
Vol 807 ◽  
pp. 135532 ◽  
Author(s):  
Rui Wang ◽  
Zhen Zhang ◽  
Lie-Wen Chen ◽  
Che Ming Ko ◽  
Yu-Gang Ma
Keyword(s):  
Cross Section ◽  
Giant Dipole Resonance ◽  
Nucleon Nucleon ◽  
Dipole Resonance
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