We have measured the reaction cross-section of some technologically important nuclide with quasi-mono energy neutron beam at Korea Institute of Radiological and Medical Sciences (KIRAMS) and bremsstrahlung beam at Pohang Accelerator Laboratory (PAL).
The neutron target system based on the 9Be(p,xn) reaction was designed and developed for proton energies 25-45 MeV. Simulations of the spectral flux from Be-target were done using Monte Carlo Simulation code MCNPX. We investigated the neutron source for Be- target with 25, 35 and 45 MeV proton beam. The quasi-mono energetic neutron source based on p+9Be/C reaction was used to irradiate target sample. Neutron fluxes were measured using 197Au as neutron flux monitor. Quasi-mono energetic neutron source was used in combination with high resolution γ-ray spectroscopic system to measure the cross-sections for 209Bi(n,xn), natPb(n,x) and 89Y(n,xn) reactions for incident neutron energies of 15.2 - 37.2 MeV. The cross-section values measured were compared with those from the literatures, EAF-2010 nuclear data, and calculations from the TALYS program and are generally in good agreement with the existing experimental data. It also provides cross-section data in the energy regions where none data previously existed.
The bremsstrahlung photons were produced when high energy electron beams of 45-65 MeV from an electron linear accelerator of the PAL were injected on a thin W-target. MCNPX were used to estimate the bremsstrahlung flux as a function of photon energy.
We have measured the flux-weighted average photo-nuclear reaction cross sections of 89Y, natAg, and natZn by irradiating high purity natural metallic foils at the un-collimated bremsstrahlung beams. The activities induced in the irradiated foils were measured with γ-ray spectrometric system. The theoretical cross-section values of 89Y(γ,xn), natAg(γ,xn) and natZn(γ,x) reaction were calculated based on the theoretical model code TALYS. The flux-weighted average cross- sections at the end-point bremsstrahlung energies of 45–65 MeV were determined by using those based on the mono-energetic photons obtained from the literature data and from the theoretical data. We found that the present measured values are in general agreed with those from the literature. We discussed the present data and the flux-weighted theoretical values from TALYS changed as a function of the end-point bremsstrahlung energy.
Thesis Advisor: Prof. Guinyun Kim