[en] Strong ³⁰Si targets of 5 mg/cm² or more were made efficiently by pressing elemental material in a gauze of 20-μm tungsten wires. (orig.)

[en] The proposed process avoids the previously necessary tempering for the curing of lattice disorder occuring during irradiation. Single crystal silicon with homogeneous phosphor doping is manufactured in the following stages: A sample of polycrystalline silicon (thermally separated in the gas phase) is transformed into the single crystalline condition, and the intensity of the required radiation is calculated from the conductivity determined then. The polycrystalline silicon is then suitably irradiated with neutrons, where the required quantity of phosphorus is formed with homogeneous distribution. Subsequently the silicon is transformed into the single crystalline condition by well known processes (crucible process according to Czochralski or process not using crucibles by the zone melting method). The equipment and several variants of the process are described. (UWI)

No abstract available

[en] We apply the QRPA formalism developed in previous works to study the excitation of the M1 mode through (e, e') scattering on ³⁰Si and ³²S. The agreement with experiment is comparable with that of the shell model for sd-shell nuclei. Having in view previous works for heavy and medium nuclei, one could conclude that the quasiparticle random-phase approximation (QRPA) is applicable to nuclei from a wide range of masses. (author)

No abstract available

[en] Powdered natural metallic silicon with the abundance ratio of ³⁰Si of 3.1% was irradiated with 60 MeV bremsstrahlung for about 7 hours. The electron beam intensity was about 240 μA. Both the reactions ³⁰Si(γ, 2p)²⁸Mg and ²⁸Si(γ, 3pn)²⁴Na occurred. The irradiated silicon was dissolved with a mixture of HF and HNO₃, and the silicon was evaporated as SiF₄. After the evaporation of silicon, the solution was dried up. By the use of a cation exchange resin, ²⁸Mg was separated from ²⁴Na. For the elution of ²⁴Na, 1N HCl was used, and for the elution of ²⁸Mg, 3N HCl was the most effective. The elution took place rapidly, and the elution curve showed quite independent peaks for ²⁴Na and ²⁸Mg. The yield of ²⁸Mg was about 3μ Ci/g Si just after the irradiation described above. This method is also excellent for making carrier-free ²⁴Na. The diffusion of magnesium in aluminum was studied through the determination of the diffusion coefficient. The diffusion annealing was performed in 10 mm Hg He at 521 - 650⁰C. The diffusion coefficient varied within 1.38 x 10^-9 and 21.6 x 10^-9 in this temperature range. (Fukutomi, T.)

No abstract available

[en] The invention concerns a process for the manufacture of homogeneous phosphorus-doped single crystal silicon by irradiation with thermal neutrons. In contrast to the normal process of irradiation of single crystals and subsequent tempering to repair radiation damage, one starts from polycrystalline silicon which is converted to the single crystal condition after neutron irradiation and thus to homogeneous phosphorus-doped material using the Czochralski crucible drawing process and the zone melting process without crucible. An example of design gives details of the irradiation process in the reactor and data on neutron flux and the phosphorus-doping achieved. (orig./PW)

[en] Angular distribution of emitted protons was measured at a deuteron energy of 12.3 MeV. The energy levels of the ³¹Si nucleus were determined with high accuracy up to an excitation energy of 9 MeV. Thirty-four bound states and 47 unbound states were observed. The contribution of the direct process to the reaction is dominant. Therefore, DWBA (Distorted Wave Born Approximation) analysis was carried out for 14 bound states and 8 unbound states and the spectroscopic factors were calculated for them. Discrepancies in spectroscopic data obtained by different authors are discussed. For instance, for the 5.28 MeV state, the DWBA calculation gives a better fit for the transferred orbital momentum l = 1 than for l = 0. Improvement of the fit by choosing a different l value was also obtained for the levels of 5.95, 6.58, and 7.43 MeV

[en] Cluster radioactivity of superheavy elements plays an important role in the identification and synthesis of superheavy elements. In 1984 Rose and Jones for the first time observed emission of ¹⁴C nucleus from ²²³Ra. In the present work, cluster radioactivity of ²⁷Al, ³⁶Ar, ⁹Be, ⁴⁰Ca, ⁴²Ca, ⁴³Ca, ⁴⁴Ca, ⁴⁶Ca, ³⁵Cl, ⁴He, ³⁹K, ⁴¹K, ⁶Li, ²⁴Mg, ²⁵Mg, ²³Na, ²⁰Ne, ²²Ne, ³²S, ³³S, ³⁴S, ²⁸Si, ²⁹Si and ³⁰Si in the superheavy nuclei Z=124 has been studied and also identified possible decay mode