Chang-Shuk Kim

Proton elastic recoil cross sections for 0.6–5.0 MeV 4He ions

Abstract The cross sections for proton elastic recoil of 0.6–5.0 MeV 4 He ions have been measured at recoil angles of 10°, 15°, 20°, 25°, 30°, 35° and 40° with the target set for transmission geometry. Thin melamine (C 3 H 6 N 6 ) foils (10–25 μg/cm 2 ) were used as the hydrogen target. By bombarding the 4 He ions normal to the target, backscattered 4 He ions from nitrogen and recoil protons at forward angles were detected. Hence the proton recoil cross section was determined by normalizing to the scattering cross section of 4 He ions backscattered from nitrogen to 165° [Y. Feng, Z. Zhou, G. Zhao, F. Yang, Nucl. Instr. and Meth. B 94 (1994) 11]. The measured cross sectional data are reviewed and compared with calculations for the kinematic inverse reaction 4 He(p,p) 4 He, and with the measured results of the proton recoil cross section reported up to now. In order to simplify the application of these results for ERD analysis, an arbitrary polynomial is derived by fitting the cross sectional data from this study.

Measurement of the stopping cross-sections of Cu, Ag and Au for 0.2–1.9 Me V He ions

Abstract The stopping cross-sections of Cu, Ag and Au are measured for He ions in the energy range 0.2–1.9 MeV by using three Rutherford backscattering methods. The reliability of each method is assessed by examining the expected deviations of measured data due to the approximation introduced in the procedure for the determination of the stopping cross-section. The measured cross-sections which have expected deviations smaller than 0.5% are fitted into the empirical formula of Eppacher and Semrad with the weighting factors based on the errors of the measurements. For Cu, Ag and Au, the stopping cross-sections deduced from the present work are in good agreement with the data of ZBL-85 within 2, 8 and 7%, respectively. The limitations of each method are considerably improved and reliable data of the stopping cross-sections are obtained.

Safety Analysis of a Hydrogen Isotopes Process

A nuclear fusion fuel cycle plant is composed of various subsystems such as a hydrogen isotope storage and delivery system, a tokamak exhaust processing system, and a hydrogen isotope separation system. Korea shares in the construction of the International Thermonuclear Experimental Reactor fuel cycle plant with the EU, Japan and US, and is responsible for the development and supply of the storage and delivery system. We thus present details on the hydrogen isotope process safety. The main safety analysis procedure is to use a hazard and operability study. Nine segments were studied how the plant might deviate from its design purpose. We present a detailed description of the process, examine every part of it to determine how deviations from the design intent can occur and decide whether these deviations can give rise to hazards. We determine possible causes and note protective systems, evaluate the consequences of the deviation, and recommend actions to achieve our safety goal.