[en] A method has been developed to reveal the depth distributions of the light elements carbon, nitrogen and oxygen in heavy matrices. For this purpose steel and zircaloy samples have been irradiated with deuterons and the neutron groups emitted in (d,n)-reactions with the different light nuclei have been measured using time-of-flight technique. The method has been applied to the study of steel samples that feature inhomogeneous carbon and nitrogen distributions and also to the measurement of diffusion profiles of oxygen in zirconium. With the present technique depth ranges of 10 to 15 μm can be analysed if the deuteron energy is chosen between 2.5 MeV and 3.5 MeV. The depth resolution improves with penetration from being of the order of 1 - 2 μm at the surface to 0.5 μm at greater depths under optimum conditions. The detection limit of the light element increases with the atomic number of the matrix and the analysed depth. For oxygen in zirconium and carbon in steel the limit of detection is of the order of 100 ppm at a depth of 10 μm. Limitations in the analysable range of the different profiles due to interfering neutron groups are discussed. The method is particularly useful for the study of oxygen profiles. It is less adequate for reactions with positive Q-values above 5 MeV. (author)

No abstract available

[en] A method has been developed to reveal the depth distributions of the light elements carbon, nitrogen and oxygen in heavy matrices. For this purpose steel and zircaloy samples have been irradiated with deuteron and the neutron groups emitted in (d,n) reactions with the different light nuclei have been recorded using time-of-flight technique. The method has been applied to the study of steel samples that feature inhomogeneous carbon and nitrogen distributions and also to the measurement of diffusion profiles of oxygen in zirconium. With the present technique depth ranges of 10-15 μm can be analysed if the deuteron energy is chosen between 2.5 MeV and 3.5 MeV. The depth resolution improves with particle penetration from being of the order of 1-2 μm at the surface to 0.5 μm at greater depths under optimum conditions. The detection limit of the light element improves with the atomic number of the matrix and the analysed depth. For oxygen in zirconium and carbon in steel the limit of detection is of the order of 100 ppm at a depth of 10 μm. Limitations in the analysable range of the different profiles due to interfering neutron groups are discussed. The method is particularly useful for the study of oxygen profiles. (Auth.)

No abstract available

[en] Scattered velocity distributions and energy transfer results obtained from detailed lattice model calculations on the Ar/W(110) system are reported and compared to recently reported molecular-beam data using a polycrystalline W target. The computed velocity distributions are found to be in good accord with the beam data provided the results from the lattice model are averaged over scattering angle. The variation of the average energy of scattered Ar with surface temperature and incident beam energy is also correctly predicted by the lattice model. The Ar--W binding energy obtained from recent hard-cube calculations on this sytem is in accord with that previously reported using the lattice model. If comparisons are made between the beam data and computed distributions that have not been averaged over scattering angle, the results do not agree. This is interpreted to be due to the polycrystalline nature of the surface used in the beam experiments, but it may be a result of a defect in the lattice model description of the interaction

No abstract available

[en] The present chapter has been formulated with the aim of making it useful in various fields of nuclear applications with emphasis on charged particle activation analysis. Activation analysis of light elements using charged particles has proved to be an important tool in solving various problems in analytical chemistry, e g those associated with metal surfaces. Scientists desiring to evaluate the distribution of light elements in the surface of various matrices using charged particle reactions require accurate data on cross sections in the MeV-region. A knowledge of cross section data and yield-functions is of great interest in many applied fields involving work with charged particles, such as radiological protection and health physics, material research, semiconductor material investigations and corrosion chemistry. The authors therefore decided to collect a limited number of data which find use in these fields. Although the compilation is far from being complete, it is expected to be of assistance in devising measurements of charged particle reactions in Van de Graaff or other low energy accelerators

[en] Oxygen in zircaloy surfaces has been determined by means of charged particle activation analysis employing the following two reactions I. ¹⁶O (d, n) ¹⁷F ->(β⁺decay) ¹⁷O Q = - 1.63 MeV; II. ¹⁶O (d, pγ) ¹⁷O Q = + 1.05 MeV. The detection limits for oxygen in such surfaces has been investigated by measuring the promptly emitted 0.87 MeV gamma rays (reaction II) and also the 511 keV annihilation radiation which arises from β-decay of ¹⁷F (reaction I). The correlation between the detection limit for oxygen in zircaloy, the particle energy and the surface thickness analyzed has been evaluated. At a deuteron energy of 3 MeV a detection limit of 0.7 x 10^-7 g/cm² was obtained from the measurement of the prompt gamma radiation arising from the second of these reactions. The analysis carried out by means of this technique is characterized by a high rapidity

No abstract available

[en] Studsvik is associated with the EUR-ATOM fusion research program and work within fusion technology is carried out regarding reactor control, conceptual design, safety and environmental impact; radiation damage. In addition research by subcontracts is done in atomic physics data at Lund university and in surface physics at Research Institute of Physics, Stockholm university. (author)