No abstract available

[en] Comparing the hydrogen content in aluminum hydroxides, one of the main components of Al-corrosion, with that in polyethylene sheets, corroded degree of practical Al-corrosions were estimated quantitatively by neutron radiography

[en] The high T_c oxide superconductor of the Bi-Pb-Sr-Ca-Cu-O system was prepared by spray pyrolysis. X-ray diffraction patterns of the sample show a perfectly isolated 110 K phase. Superconducting transition with zero-resistance temperture at T_c = 101 K was achieved for a sample calcined at 850 degree C for 18 hr and sintered at the same temperature for 12 hr. The heat treatment time required to form the pure 110 K phase could be minimized by spray pyrolysis. The critical current density at 77 K in zero magnetic field was 528 A/cm²

[en] An improved fitting function is proposed for the thermal neutron distribution in water due to Ra-Be source. A correction for estimating the neutron yields from a Ra-Be source is also alluded to. (Auth.)

[en] The water bath method for calibrating a Ra-Be neutron source was simplified by introducing a fitting function for the thermal neutron distribution in water. The simplified method requires only measurement of neutrons at a single position in a comparatively small water bath. (Auth.)

[en] The photonuclear reaction ⁹Be(γ,n) was used to measure the intensity I(2009.8) of the crossover E4 transition in ⁴⁶Ti by an improved method. A point-like ⁴⁶Sc source was used to provide the ⁴⁶Ti. Neutrons generated by the ⁴⁶Ti gamma rays were detected with BF₃ counters. The observed intensity per decay of⁴⁶Sc was I(2009.8) = (1.3+-1.0)x10^-7, which agrees well with a previous estimate. From the present result the reduced transition probability B(E4)sub(ex) and the partial mean life-time tau(E4) of the crossover E4 transition between the 2009.8 keV, 4⁺ state and the ground state in ⁴⁶Ti were estimated as B(E4)sub(ex)=(5.6+-4.9)x10^-99e² cm⁸ and tau(E4)=(1.7+-1.3)x10^-5 s, respectively. (auth)

[en] In chapter 1 are described measurements of cross sections σ(E sub(ß)) of the ₉Be(ß, n) reaction with six kinds of radioisotopes. The results were σ(1674.7) = 8.8 +- 1.6, σ(1705.2) = 13.3 +- 2.4, σ(1724.9) = 11.0 +- 2.0, σ(1778.9) = 7.3 +- 1.3, σ(1836.0) = 4.7 +- 0.9, and σ(2167.6) = 1.8 +- 0.4 in unit of 10^-₂₈ cm₂. The cross sections measured show a cusp-like peak near the threshold, and its width is narrower than that observed by Jakobson with bremsstrahlung X-rays. Comparison of the present results with theories indicates that mutual agreement is yet qualitative. In chapter 2 is described a measurement of the intensity I(2009.8) of the crossover E4 transition in ₄₆Ti by applying the ₉Be(ß, n) reaction. The observed intensity per decay of ₄₆Sc was I(2009.8) = (1.2 +- 0.7) x 10^-₇. From the present result the reduced transition probability B(E4) of the crossover E4 transition between the 2009.8 keV, 4⁺ excited state and the 0⁺ ground state of ₄₆Ti was estimated as B(E4) = (5.2 +- 3.7) x 10^-₉₉ e₂.cm₈. Discussion was given of the presently measured intensity and of nuclear models. (author)

[en] Depth profiles of tritium in a thin titanium layer were measured using the T(d, α)n reaction. A new sample showed a nearly rectangular profile of tritium with concentrations from 1.1 to 1.2 atomic ratios (T/Ti). After the bombardment of 360 or 570 keV D₃⁺ ions at 20⁰C a dip was formed on the profile about the projected range of the incident ions, which indicates that tritium atoms and deuterium atoms were mixed at the implanted sites and then diffused. At a high dose rate of about 16 μA/cm² two dips were observable on the profile, in which a peak was formed about the projected range. For a temperature of -110⁰C the profile showed almost no change after a bombardment and the succeeding annealing at room temperature for 20 h. These results are discussed on the basis of the previous results. (orig.)

[en] A method for the measurement of depth profiles of tritium in solids has been developed in which the ³H(d,n)⁴He reaction is used. This method is nondestructive with relatively high depth resolution in the surface region of the solids. The validity of the present method has been supported by the examination of the depth profile measured for a tritium target as is used for a neutron source

[en] Using 1576-keV γ-rays from sup(142)Pr, the cross section of the direct three-body breakup of sup(9)Be was measured and found to be (4.0 +- 1.8) x 10sup(-1)μb. This result is in approximate agreement with Salyers' theoretical estimate based upon a cluster model of sup(9)Be