No abstract available

[en] The first biased limiter experiment has been done in Heliotron E, which is a typical stellarator/heliotron type device. This experiment investigates the boundary physics of the currentless plasmas, which are produced in the magnetic limiter (divertor) configuration. We analyze the experimental results related to the surface potential, recycling process, and plasma parameters using a material limiter which was biased from the vacuum chamber. The boundary density profile was measured by a thermal Li beam probe to investigate the effect of the biased limiter. (author)

[en] Measurements were done to obtain the one-dimensional sizes of rapidly fluctuating bursts with fast spikes whose rise times are typically about one second, and in some extreme cases less than 0.1 second. The results of two bursts with fast spikes are presented. One has a soft spectrum, and the other has a very hard spectrum. The measured one-dimensional size of both events indicates relatively a small size and simple structure. It can be said, however, that the source size is not so small as expected from its rapid time variations. Therefore, a thermal explanation of these bursts seems to be excluded

No abstract available

[en] We have developed a practical code system to calculate double differential cross sections of all emitted particles and kerma factors for the n+¹²C reaction in the energy region from 20 to 80 MeV, and compared the results calculated using the code system with experimental data. As a result, it has been found that the code system is applicable to nuclear data evaluation of ¹²C in JENDL high energy file. (author)

[en] Pressure-driven MHD instabilities Heliotron E were studied by shifting the vacuum magnetic axis outward (Δ_ν > 0) or inward (Δ_ν < 0), and/or applying an additional toroidal field additively or subtractively. The global stability aspects of experimental results are consistent with the theoretical predictions using the ideal and resistive MHD model based on the stellarator expansion approximation. Stability improvement was obtained for the β(0) <= 1% regime in case where the additive toroidal field was (3-8)% of the toroidal component from the helical coils for -2 cm ≤ Δ_ν ≤ 0 cm. It is believed that the pressure profile due to toroidal field effect was unintentionally adjusted to improve stability instead of the magnetic hill. For higher beta β(0) > 2-3%. It was found that the m = 1/n = 1 mode associated with the slash-l = 1 rational surface became strongly unstable, which may limit the central beta value. Strong coherence was also observed between B-tilde_θ (m = 1 / n = 1) and n-tilde l (m = 1 / n = 1). (author). 10 refs, 10 figs

[en] A trial wavefunction is constructed for nuclear matter in terms of the reaction matrix. The trial function includes only two-particle excitations and the resulting energy expectation value for two-nucleon forces with a state-independent repulsive core of Yukawa shape approaches in the thermodynamic limit the energy given by the lowest order Brueckner theory with standard dispersion. Evaluation of the energy expectation value is carried out in a systematic way by use of an identity that holds between the Hamiltonians and reaction matrix. (Author)

[en] Double-differential proton emission cross sections were measured for proton-induced reactions on several medium-heavy nuclei (^54,56Fe, ⁶⁰Ni, ⁹⁰Zr, and ⁹³Nb) at two incident energies of 14.1 and 26 MeV. The (p,p') data for ⁵⁶Fe and ⁹³Nb were compared with available data of (n,n') scattering for the same target nuclei and incident energies, and both data were analyzed using the Feshbach-Kerman-Koonin model to extract the strength V₀ of the effective N-N interaction which is the only free parameter used in multistep direct calculations. (author)

[en] We have evaluated the cross sections for neutrons with incident energies from 20 to 80 MeV on ¹²C for the JENDL high-energy file. The total cross sections were determined by a generalized least-squares method with available experimental data. The cross sections of elastic and inelastic scattering to the first 2⁺ were evaluated with the theoretical calculations. The optical potentials necessary for these calculations were derived using a microscopic approach by Jeukenne-Lejeune-Mahaux. For the evaluation of double differential emission cross sections (DDXs), we have developed a code system SCINFUL/DDX in which total 35 reactions including the 3-body simultaneous breakup process (n+¹²C → n+α+⁸Be) can be taken into consideration in terms of a Monte Carlo method, and have calculated the DDXs of all light-emissions (A≤4) and heavier reaction products. The results for protons, deuterons, and alphas showed overall good agreement with experimental data. The code is also applicable for calculations of total and partial kerma factors. Total kerma factors calculated for energies from 20 to 80 MeV were compared with the measurements and the other latest evaluations from the viewpoints of medical application and nuclear heating estimation. (author)

No abstract available