Cross-sections for the 27 ⁣Al(γ,x)24Na{^{27}\!\rm{Al}}(\gamma,\textit{x})^{24}\rm{Na} multiparticle reaction at EγmaxE_{\rm{\gamma max}} = 40 ÷\div 95 MeV

The bremsstrahlung flux-averaged cross-sections $\langle{\sigma(E_{\rm{\gamma max}})}\rangle$ and the cross-sections per equivalent photon $\langle{\sigma(E_{\rm{\gamma max}})_{\rm{Q}}}\rangle$ were measured for the photonuclear multiparticle reaction $^{27}\!\rm{Al}(\gamma,\textit{x}; \textit{x} = {^{3}\rm{He}} + pd + 2pn)^{24}\rm{Na}$ at bremsstrahlung end-point energies ranging from 40 MeV to 95 MeV. The experiments were performed using the beam from the NSC KIPT electron linear accelerator LUE-40 with the use of the $\gamma$-activation technique. The bremsstrahlung quantum flux was calculated with the program GEANT4 and, in addition, was monitored by means of the $^{100}\rm{Mo}(\gamma,n)^{99}\rm{Mo}$ reaction. The cross-sections $\sigma(E)$ were computed using the TALYS1.9 code with the default options. The measured average cross-sections $\langle{\sigma(E_{\rm{\gamma max}})}\rangle$ and $\langle{\sigma(E_{\rm{\gamma max}})_{\rm{Q}}}\rangle$ have appeared to be higher by factors of 2.0 to 2.4 than the theoretical results. The experimental results have been found to be in good agreement with the data of other laboratories. Consideration is given to special features of calculation of $\langle{\sigma(E_{\rm{\gamma max}})}\rangle$ and $\langle{\sigma(E_{\rm{\gamma max}})_{\rm{Q}}}\rangle$ for the $^{27}\!\rm{Al}(\gamma,\textit{x})^{24}\rm{Na}$ reaction, with occurrence of three $^{27}\!\rm{Al}$ photodisintegration channels. The paper also discusses the possibility of using the $^{27}\!\rm{Al}(\gamma,\textit{x})^{24}\rm{Na}$ reaction for monitoring the bremsstrahlung $\gamma$-quantum flux in the photon energy region above 30 MeV.Comment: 16 pages, 6 figures, 1 tabl

Magnetic system for cleaning the gamma beam at the LUE-40 electron linac output

The bremsstrahlung of accelerated electrons passing through a converter is used to study multiparticle photo-nuclear reactions. The results of calculations, numerical modeling, design, and testing of a special magnetic cleaning system to obtain a "pure" beam of bremsstrahlung quanta when studying the cross-sections of such reactions at the LUE-40 linac are presented. The system is based on commercially available permanent magnets of rectangular cross-sections. The maximum on-axis field is 0.9 T, which provides sufficient separation of the electron beam and gamma rays at a distance of more than 90 mm from the magnet.Comment: 9 pages, 8 figure

Cross-sections for the 27 ⁣al(γ,x)22na{^{27}\!\rm{al}}(\gamma,\textit{x})^{22}\rm{na} multichannel reaction with the 28.3 mev difference of the reaction thresholds

The bremsstrahlung flux-averaged cross-sections $\langle{\sigma(E_{\rm{\gamma max}})}\rangle$ and the cross-sections per equivalent photon $\langle{\sigma(E_{\rm{\gamma max}})_{\rm{Q}}}\rangle$ were first measured for the photonuclear multichannel reaction ${^{27}\!\rm{Al}}(\gamma,\textit{x})^{22}\rm{Na}$ at end-point bremsstrahlung gamma energies ranging from 35 MeV to 95 MeV. The experiments were performed with the beam from the NSC KIPT electron linear accelerator LUE-40 with the use of the $\gamma$-activation technique. The bremsstrahlung quantum flux was calculated with the program GEANT4.9.2 and, in addition, was monitored by means of the $^{100}\rm{Mo}(\gamma,n)^{99}\rm{Mo}$ reaction. The flux-averaged cross-sections were calculated using the partial cross-section $\sigma(E)$ values computed with the TALYS1.95 code for different level density models. Consideration is given to special features of calculating the cross-sections $\langle{\sigma(E_{\rm{\gamma max}})}\rangle$ and $\langle{\sigma(E_{\rm{\gamma max}})_{\rm{Q}}}\rangle$ for the case of the final nucleus $^{22}\rm{Na}$ production in the $^{27}\!\rm{Al}$ photodisintegration reaction via several partial channels $\textit{x}$: $\rm{n}\alpha + dt + npt + 2n{^{3}\rm{He}} + n2d + 2npd + 2p3n$.Comment: 8 pages, 9 figures, 1 table, 19 references. arXiv admin note: text overlap with arXiv:2012.1447

Photoneutron cross-sections for the reactions

The flux-averaged cross-sections $$\langle {\sigma (E_{\gamma \mathrm{max}})}\rangle$$ for the $$^{181}\mathrm{Ta}(\gamma ,\textit{x}n; \textit{x} = 1$$–$$8)^{181-\textit{x}}\mathrm{Ta}$$ reactions have been measured at the end-point bremsstrahlung energies of 80–95 MeV. The experiments were performed by using the beam from the NSC KIPT electron linear accelerator LUE-40 and measuring the residual $$\gamma$$-ray activities of the reaction products. The theoretical $$\langle {\sigma (E_{\gamma \mathrm{max}})}\rangle$$ values were computed using the mono-energetic cross-sections $$\sigma (E)$$ from TALYS1.9 code. A comparison between the measured average cross-sections and the theoretical values show good agreement for the $$(\gamma ,1$$–$$6\mathrm{n})$$ reactions but substantial differences for the $$(\gamma ,7\mathrm{n})$$ and $$(\gamma ,8\mathrm{n})$$ reactions. Isomeric average cross-section ratios $$d(E_{\gamma \mathrm{max}})$$ of a product $$^{178g,m}\mathrm{Ta}$$ produced from the $$^{181}\mathrm{Ta}(\gamma ,3\mathrm{n})$$ reaction have been obtained. The results have been compared with the literature data and the theoretical values based on TALYS1.9 code

Isomer ratios for product of photonuclear reaction 107Ag(γ, 3n)104m,gAg in the energy region 35 ÷ 40 MeV

The paper deals with the results of isomer ratio calculations for photonuclear reaction at 107Ag with 3 neutrons escape. Bremsstrahlung energies varied within 35 ÷ 40 MeV. The instrumental gamma-ray spectra of irradiated target specimens have been measured with high purity germanium semiconductor spectrometer. The isomer ratio results and dependence of isomer ratios upon maximal bremsstrahlung energy within selected range are obtained

The 7Li(18O, 17O)8Li reaction and the 17O + 8Li potential

This paper deals with the results of isomer ratio measurements for nuclei 110m,gIn and 108m,gIn from photonuclear reactions 113In(γ, 3n)110m,gIn, 115In(γ, 5n)110m,gIn, 115In(γ, 7n)108m,gIn. Bremsstrahlung energies varied within (34÷43) MeV for 113In(γ, 3n)110m,gIn reaction, in energy region (43÷100) MeV for 115In(γ, 5n)110m,gIn and 115In(γ, 7n)108m,gIn reactions. The instrumental gamma-ray spectra of irradiated target specimens have been measured with high purity germanium semiconductor spectrometer. The isomer ratio results and dependence of isomer ratios upon maximal bremsstrahlung energies within selected range are obtained and discussed