[en] We report the activities for nuclear data measurements using charged particle-, neutron-, and photon-induced reactions in Korea. Charged particle-induced reaction cross-sections are determined by using the stacked-foil activation technique at the MC-50 cyclotron facility in the Korean Institute of Radiological and Medical Science. Neutron-induced nuclear data were measured by using the pulsed neutron facility, which consists of an electron linear accelerator, a water-cooled Ta target with a water moderator, and a 12 m time-of-flight path. It can be possible to measure the neutron total cross-sections in the neutron energy range from 0.01 eV to few hundreds eV by using the neutron time-of-flight method and also measured the photo-neutron cross-sections by using the Bremsstrahlung from the electron linac. We collaborated with foreign researchers in India, Japan, Russia, China, and Vietnam. We also utilized foreign facilities in India, Japan, Russia, and USA. (author)

[en] We studied the production of medically applicable scandium radioisotopes through the ^natTi(p,x) reactions with in the energy range of their threshold to 44 MeV. The excitation functions of ^natTi(p,x) reactions and thick target yield of scandium radioisotopes (^{43,44m,44g,46,47,48}Sc) and by-product (⁴⁸V) were also measured. For this purpose, pure thin titanium foils were stacked and irradiated with different proton energies by using the MC-50 cyclotron at the Korea Institute of Radiological and Medical Sciences (KIRAMS), Korea. The data acquisition and activation analysis was performed by using an off-line γ-ray spectrometry technique. The measured results were compared with literature data as well as the data from the TENDL-2017 library based on TALYS-1.9 code. The integral yields for the thick target using the measured cross section were also presented. The results reveal that ^natTi(p,x) reaction is one of the best route for the production of medical radioisotopes of ^{43,44m,44g,46,47,48}Sc with controllable impurity of ⁴⁸V. (author)

[en] The present measured values are compared with the data in both the EXFOR library, evaluated nuclear data library ENDF/B-VII.1 [2] and the TENDL-2013 library based on the TALYS 1.6 code. Neutron activation cross sections induced in "2"7Al at 15.2, 26.4 and 37.2 MeV were measured by the activation and off-line gamma spectroscopy technique by using quasi-mono energetic neutron fields from the "9Be(p,xn) reactions. Quasi-mono-energetic neutron sources from the "9Be(p,xn) reaction for proton beam energies of 25, 35 and 45 MeV at KIRAMS were used. The present measured values were compared with theoretical model TENDL-2013, ENDF/B-VII. and with results from earlier measurements. The present results are in a good agreement with the experimental literature data

[en] The cross sections of the ${}^{96}$Zr(n, 2n)${}^{95}$Zr, ${}^{90}$Zr(n, 2n)${}^{89}$Zr, and ${}^{90}$Zr(n, 3n)${}^{88}$Zr reactions with the average neutron energies of 13.8-31.33 MeV were measured by using the activation and an off-line γ-ray spectrometric technique. The cross sections for the ${}^{96}$Zr(n, 2n)${}^{95}$Zr reaction at the average neutron energies of 18.91 MeV and 25.81 MeV, for the ${}^{90}$Zr(n, 2n)${}^{89}$Zr reaction at 28.74 MeV as well as for the ${}^{90}$Zr(n, 3n)${}^{88}$Zr reaction in the average energies of 27.37 MeV and 31.33 MeV are the first time measurements. The fast neutrons were generated by using the ${}^9$Be(p, n) reaction with the proton energies of 25-, 35- and 45-MeV from the MC-50 Cyclotron at the Korea Institute of Radiological and Medical Sciences (KIRAMS). The neutron spectra were simulated by using the computer code MCNPX 2.6., whereas the experimental neutron fluxes were monitored based on the ${}^{27}$Al(n, α)${}^{24}$Na reaction. The cross sections for the ${}^{96}$Zr(n, 2n)${}^{95}$Zr, ${}^{90}$Zr(n, 2n)${}^{89}$Zr, and ${}^{90}$Zr(n, 3n)${}^{88}$Zr reactions induced by mono-energetic neutrons were also calculated by using the TALYS 1.9 code. The present results are compared with the literature data and the theoretical values, and are found to be in good agreement.

[en] The "n"a"tAg(n, xn)"1"0"6"m","g","1"0"4"m","g","1"0"5gAg reaction cross-sections within the neutron energies of 14-37 MeV were determined by using an activation and off-line γ-ray spectrometric technique. The quasi-mono energetic neutron beams were produced from the "9Be(p, xn)"9B reaction by using the proton beams of 25, 35, and 45 MeV at the Korean Institute of Radiological and Medical Sciences, Korea. Monte Carlo simulation code MCNPX was used to simulate the neutron energy spectra, whereas the theoretical cross-sections were calculated using the TALYS 1.8 code. The experimental and theoretical reaction cross-sections show similar trends from lower to higher neutron energy. The isomeric cross-section ratios of "1"0"4"m","gAg and "1"0"6"m","gAg for the "n"a"tAg(n, xn) reactions were also obtained from the experimental values of present work and compared with the literature data. (author)

[en] Highlights: • The flux-weighted average cross sections of ¹²⁷I(γ,xn)^126,124,123I reactions were experimentally determined. • The present result indicates the role of excitation energy and GDR effect. • The production cross-sections of radioactive iodine isotopes are important for the useful medical purpose. - Abstract: The flux-weighted average cross sections of ¹²⁷I(γ,xn)^126,124,123I reactions were experimentally determined with the bremsstrahlung end-point energies of 50 and 70 MeV by activation and off-line γ-ray spectrometric technique, using the 100 MeV electron linac at the Pohang Accelerator Laboratory, Korea. The ¹²⁷I(γ,xn)^126−121I reaction cross sections as a function of photon energy were theoretically calculated using the TALYS 1.8 code. The flux-weighted average cross sections of ¹²⁷I(γ, xn)^126,124,123I reactions as a function of bremsstrahlung end-point energies were also obtained from the literature and TALYS data based on mono-energetic photons and are found to be in close agreement with the present data. The experimental and theoretical ¹²⁷I(γ, xn)^126−121I reaction cross-sections increase with bremsstrahlung energy, which indicates the role of excitation energy. After a certain energy, the individual ¹²⁷I(γ, xn)^126−121I reaction cross sections decrease with increase of bremsstrahlung energy due to opening of other reactions, which indicates sharing of energy in different reaction channels. The radioactive iodine isotopes production cross-sections are important for the useful medical purpose.

[en] The flux weighted average cross sections and the isomeric yield ratios of ^{110m, g}In, ^{111m, g}In and ^{112m, g}In in the ^natIn(γ,xn) ^112-110In reactions with the bremsstrahlung end-point energies of 65, 70 and 75 MeV have been determined by activation and off-line γ-ray spectrometric technique using the 100 MeV electron linac at Pohang accelerator laboratory, Korea. It was found that the ^natIn(γ,xn) ^112-110In reaction cross sections increase very fast from the threshold energy to a certain value of the bremsstrahlung energy, where the other reaction channel opens. After a certain energy, it remains constant because the cross section of the other reaction channel starts to increase. This indicates the partition of the excitation energy in different reaction channels. The isomeric yield ratios of ^{110m, g}In, ^{111m, g}In and ^{112m, g}In in the ^natIn(γ,xn) reactions decrease very fast with the bremsstrahlung end-point energy from the threshold value to 15-30 MeV due to the giant dipole resonance (GDR) effect. Above that, the isomeric yield ratios increase slowly with the bremsstrahlung energy due to the increase of excitation energy. (orig.)

[en] Studies of high-energy nuclear reactions are of great important. It may help in deeper understanding of the reaction mechanisms and in extending of various fields of applications such as astrophysics, radiation physics, intense neutron source production and nuclear waste transmutation. The aim of the present work is to investigate the multineutron photonuclear on "1"9"7Au bombarded by 2.5 GeV Bremsstrahlung. Most of the photodisintegration products of gold with half-lives sufficient for the activity measurement. In this work, the necessary corrections were made in order to improve the accuracy of the experimental results The obtained experimental results are in good agreement with the calculated values. The yields for the "1"9"7Au(γ,xn)"1"9"7-xAu reactions depend not only on the excitation energies but also on the number of neutrons ejected

[en] We measured the flux-weighted average cross-sections of the ¹⁰⁰Mo(n, 2n)⁹⁹Mo and ⁹²Mo(n, 3n)⁹⁰Mo reactions with the average neutron energies between 14.0- and 31.8-MeV by using an activation and off-line γ-ray spectrometric technique. The fast neutrons were generated based on the ⁹Be(p, n) reaction with the proton energies of 25-, 35- and 45-MeV from the MC-50 Cyclotron at the Korea Institute of Radiological and Medical Sciences (KIRAMS). The neutron flux was measured by using the ²⁷Al(n, α)²⁴Na monitor reaction, whereas the neutron spectra were simulated by using the MCNPX 2.6.0 code. The theoretical cross-sections of the ¹⁰⁰Mo(n, 2n)⁹⁹Mo and ⁹²Mo(n, xn)^91.90,89Mo reactions as a function of mono-energetic neutron were calculated by using the TALYS-1.9 code. The present results for the ¹⁰⁰Mo(n, 2n)⁹⁹Mo and ⁹²Mo(n, 3n)⁹⁰Mo reactions are compared with the calculated neutron flux-weighted average values based on the literature data and theoretical cross-sections as a function of mono-energetic neutron energy, and show a good agreement.

[en] We measured neutron-induced reaction cross-sections for ⁸⁹Y(n,2n)⁸⁸Y, ⁸⁹Y(n,3n)⁸⁷Y, and ⁸⁹Y(n,4n)⁸⁶Y reactions with the average neutron energy region from 15.9 to 36.3 MeV by using an activation and off-line γ-ray spectrometric technique. High energy neutrons were produced from the ⁹Be(p,n) reaction with 25-, 35- and 45-MeV proton beam from the MC-50 Cyclotron at Korea Institute of Radiological and Medical Sciences (KIRAMS). The neutron-induced reaction cross-sections of ⁸⁹Y as a function of neutron energy were calculated using the TALYS 1.6. The flux-weighted average cross-sections for ⁸⁹Y(n,xn; x = 2-4) reactions are also calculated from the TALYS values based on mono-energetic neutron and by using the neutron spectrum from MCNPX 2.6.0 code. The present results for ⁸⁹Y(n,xn; x = 2-4) reactions are compared with the flux-weighted values of TALYS and are found to be in good agreement. (author)