Design of an acceleration gap using mesh electrodes of the brightness enhancement system for the slow positron beamline of Kyoto University research reactor was studied to improve the performance of brightness enhancement. The transmittance and the increase in the angular divergence of the beam resulting from acceleration with the mesh electrode were estimated by trajectory simulations. The effect of the increase in the beam emittance on the beam radius at the focus point was estimated based on the analytical solution of the beam envelope equation. Using the obtained beam transmittance and beam radius, the beam brightness after remoderation was evaluated. Then, the influence of the mesh electrode configuration on the brightness was investigated.
The irradiation setup at the ion microprobe SNAKE is used to irradiate living cells with single energetic ions. The irradiation accuracy of 0.55μm and respectively 0.40μm allows to irradiate substructures of the cell nucleus. By the choice of ion atomic number and energy the irradiation can be performed with a damage density adjustable over more than three orders of magnitude. Immunofluorescence detection techniques show the distribution of proteins involved in the repair of DNA double-strand breaks. In one of the first experiments the kinetics of appearance of irradiation-induced foci in living HeLa cells was examined. In other experiments a new effect was detected which concerned the interaction between irradiation events performed at different time points within the same cell nucleus.
Nuclear facilities as nuclear power stations, nuclear research reactors, particle accelerators and linear accelerator in medical institution using concrete in building construction. The different type materials of the aggregate as component of concrete were analyzed to provide radiation protection. The energy deposited the transmission factor and the mass attenuation coefficients in ordinary and barite concretes have been calculated with the photon transport Monte Carlo software. The numerical simulations results show that using barite as an aggregate in the concrete is one of the solutions for gamma ray shielding. Thereat, it is shown non-destructive method for determining the gamma radiation absorption characteristics of concrete.
The linear attenuation coefficients of water and some solid phantom materials, namely of solid water RMI-457, of plastic water, of RW3 solid water, and of Perspex were determined by Monte Carlo calculations, for gamma-ray photons with energies of 59.5, 80.9, 140.5, 356.5, 661.6, 1173.2, and 1332.5 keV. The calculated values were compared with the experimental results presented by other researchers and with theoretical values obtained using the XCOM database. Good agreement was observed between the calculations, the experimental, and the theoretical values. The results indicate that the process in Monte Carlo code can be followed to determine the equivalency of other materials at several energies. Three shielding factors such as half-value layer, tenth-value layer, and mean free path were calculated at all considered gamma-ray energies.
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