First Measurements of Spin-Dependent Double-Differential Cross Sections and the GDH Integrand from \vec{^3He}(\vec{\gamma},n)pp at Incident Photon Energies of 12.8 and 14.7 MeV

The first measurement of the three-body photodisintegration of longitudinally-polarized ^3He with a circularly-polarized \gamma-ray beam was carried out at the High Intensity \gamma-ray Source (HI\gamma S) facility located at Triangle Universities Nuclear Laboratory (TUNL). The spin-dependent double-differential cross sections and the contributions from the three-body photodisintegration to the ^3He GDH integrand are presented and compared with state-of-the-art three-body calculations at the incident photon energies of 12.8 and 14.7 MeV. The data reveal the importance of including the Coulomb interaction between protons in three-body calculations.Comment: 5 pages, 3 figures, accepted in Physical Review Letter

Spin-dependent cross sections from the three-body photodisintegration of He 3 at incident energies of 12.8 and 14.7 MeV

The first measurement of the three-body photodisintegration of polarized 3He using a circularly polarized photon beam has been performed at incident energies of 12.8 and 14.7 MeV. This measurement was carried out at the high-intensity γ-ray source located at Triangle Universities Nuclear Laboratory. A high-pressure 3He target, polarized via spin exchange optical pumping with alkali metals, was used in the experiment. The spin-dependent double- and single-differential cross sections from 3He(γ,n)pp for laboratory angles varying from 30° to 165° are presented and compared with state-of-the-art three-body calculations. The data reveal the importance of including the Coulomb interaction between protons in the three-body calculations

Towards a More Complete and Accurate Experimental Nuclear Reaction Data Library (EXFOR): International Collaboration Between Nuclear Reaction Data Centres (NRDC)

The International Network of Nuclear Reaction Data Centres (NRDC) coordinated by the IAEA Nuclear Data Section (NDS) is successfully collaborating in the maintenance and development of the EXFOR library. As the scope of published data expands (e.g., to higher energy, to heavier projectile) to meet the needs from the frontier of sciences and applications, it becomes nowadays a hard and challenging task to maintain both completeness and accuracy of the whole EXFOR library. The paper describes evolution of the library with highlights on recent developments.Comment: 4 pages, 2 figure

Double differential light charged particle emission cross sections for some structural fusion materials

International Conference on Nuclear Data for Science and Technology (ND) -- SEP 11-16, 2016 -- Bruges, BELGIUMSARPUN, Ismail Hakki/0000-0002-9788-699XWOS: 000426429500253In fusion reactors, neutron induced radioactivity strongly depends on the irradiated material. So, a proper selection of structural materials will have been limited the radioactive inventory in a fusion reactor. First-wall and blanket components have high radioactivity concentration due to being the most flux-exposed structures. The main objective of fusion structural material research is the development and selection of materials for reactor components with good thermo-mechanical and physical properties, coupled with low-activation characteristics. Double differential light charged particle emission cross section, which is a fundamental data to determine nuclear heating and material damages in structural fusion material research, for some elements target nuclei have been calculated by the TALYS 1.8 nuclear reaction code at 14-15 MeV neutron incident energy and compared with available experimental data in EXFOR library. Direct, compound and pre-equilibrium reaction contribution have been theoretically calculated and dominant contribution have been determined for each emission of proton, deuteron and alpha particle.Afyon Kocatepe University's Scientific Research Office (BAPK) [16.KARIYER.34]This work is supported by the Afyon Kocatepe University's Scientific Research Office (BAPK) Contract No. 16.KARIYER.34

Neutron radiative capture cross section for sodium with covariance analysis

The neutron radiative capture cross sections measurement has been carried out for the $$^{23}$$Na nucleus in the neutron energy region from 0.6 to 3.2 MeV using the neutron activation technique followed by off-line $$\gamma$$-ray spectrometry. The measurement was made relative to the $$^{115}$$In(n,n$$\prime$$$$\gamma$$)$$^{115}\hbox {In}^{m}$$ reference monitor reaction cross section. The neutrons were produced via the $$^{7}$$Li(p,n)$$^{7}$$Be reaction. Detailed uncertainty propagation has been performed using the covariance analysis, and the measured cross sections are being reported with their uncertainties, covariance, and correlation matrix. The necessary corrections have been made for the low background neutron energy contribution, $$\gamma$$-ray true coincidence summing, and self-attenuation process. The obtained neutron spectrum averaged cross sections of $$^{23}$$Na(n,$$\gamma$$)$$^{24}$$Na are discussed and compared with the existing cross sections data retrieved from the EXFOR database. EMPIRE-3.2 and TALYS-1.9 calculations were performed in order to determine the radiative capture cross section in this energy region. The present results are also compared with the evaluated nuclear data from ENDF/B-VIII.0, TENDL-2019, IRDFF-1.05, JENDL-4.0, and JEFF-3.3. The obtained cross section results are in good agreement with existing experimental data, evaluated libraries, and reaction models for the highest energy points (2.11 and 3.13 MeV), while the lowest-energy point at 0.61 MeV underestimates them

Systematic study of (n, p) reaction cross sections from the reaction threshold to 20 MeV

The cross sections of Cr-nat(n, x)V-52, Cr-52(n, p)V-52, Cr-nat(n, x)V-53, Cr-53(n, p)V-53, Zn-nat(n, x)Cu-66, Zn-66(n, p)Cu-66, Zn-nat(n, x)Cu-68(m), Zn-68(n, p)Cu-68(m), Mo-nat(n, x)Nb-97(g), Mo-97(n, p)Nb-97(g), Mo-nat(n, x)Nb-97(m), Mo-97(n, p)Nb-97(m), Sn-nat(n, x)In-116(m1+m2), Sn-116(n, p)In-116(m1+m2), Sn-nat(n, x)In-117(g), Sn-117(n, p)In-117(g), Sn-nat(n, x)In-118(m1+m2), Sn-118(n, p)In-118(m1+m2), Sn-nat(n, x)In-120(x), Sn-120(n, p)In-120(x), Ba-nat(n, x)Cs-138, and Ba-138(n, p)Cs-138 reactions have been measured at 14.8 MeV neutron energy. In the present work, the contributions of (n, np), (n, pn), and (n, d) reactions from heavier isotopes are subtracted. The cross sections were also estimated with the TALYS-1.2 nuclear model code using different level density models, at neutron energies varying from the reaction threshold to 20 MeV. The variations in the (n, p) cross sections with the neutron number in the isotopes of an element are also discussed in brief

Prospective clinical and molecular evaluation of potential Plasmodium ovale curtisi and wallikeri relapses in a high-transmission setting

Background Plasmodium ovale curtisi and wallikeri are perceived as relapsing malarial parasites. Contrary to Plasmodium vivax, direct evidence for this hypothesis is scarce. The aim of this prospective study was to characterize the reappearance patterns of ovale parasites. Methods P. ovale spp. infected patients were treated with artemether-lumefantrine and followed biweekly for up to 1 year for the detection of reappearing parasitemia. Molecular analysis of reappearing isolates was performed to identify homologous isolates by genotyping and to define cases of relapse following predefined criteria. Results At inclusion, 26 participants were positive for P. ovale curtisi and/or P. ovale wallikeri. The median duration of follow-up was 35 weeks. Reappearance of the same P. ovale species was observed in 46% of participants; 61% of P. ovale curtisi and 19% of P. ovale wallikeri infection-free intervals were estimated to end with reappearance by week 32. Based on the predefined criteria, 23% of participants were identified with 1 or 2 relapses, all induced by P. ovale curtisi. Conclusion These findings are in line with the currently accepted relapse theory inasmuch as the reappearance of P. ovale curtisi strains following initial blood clearance was conclusively demonstrated. Interestingly, no relapse of P. ovale wallikeri was observed.</p

Prospective Clinical and Molecular Evaluation of Potential Plasmodium ovale curtisi and wallikeri Relapses in a High-transmission Setting

BACKGROUND:Plasmodium ovale curtisi and wallikeri are perceived as relapsing malarial parasites. Contrary to Plasmodium vivax, direct evidence for this hypothesis is scarce. The aim of this prospective study was to characterize the reappearance patterns of ovale parasites. METHODS:P. ovale spp. infected patients were treated with artemether-lumefantrine and followed biweekly for up to 1 year for the detection of reappearing parasitemia. Molecular analysis of reappearing isolates was performed to identify homologous isolates by genotyping and to define cases of relapse following predefined criteria. RESULTS:At inclusion, 26 participants were positive for P. ovale curtisi and/or P. ovale wallikeri. The median duration of follow-up was 35 weeks. Reappearance of the same P. ovale species was observed in 46% of participants; 61% of P. ovale curtisi and 19% of P. ovale wallikeri infection-free intervals were estimated to end with reappearance by week 32. Based on the predefined criteria, 23% of participants were identified with 1 or 2 relapses, all induced by P. ovale curtisi. CONCLUSION:These findings are in line with the currently accepted relapse theory inasmuch as the reappearance of P. ovale curtisi strains following initial blood clearance was conclusively demonstrated. Interestingly, no relapse of P. ovale wallikeri was observed