[en] We report updated analysis results on an np elastic experiment at LAMPF and a pp experiment at the ZGS. We have measured two np spin asymmetry parameters, C/sub LL/ and C/sub SL/, at beam energies 500, 650, and 800 MeV. The cm scattering angles of neutrons measured ranged from 80⁰ through 180⁰. We observed very large C/sub LL/ at backward angles for the first time. The pp experiment at the ZGS was a measurement of the difference between the pp total cross sections for parallel and antiparallel longitudinal spin states at beam momenta 2.75, 2.92, 3.25, 3.75, and 4.00 GeV/c. These results reveal possible new structures in this momentum range. Masses for these structures are about 2700 and 2900 MeV

[en] Using the now closed Argonne ZGS polarized-proton beam, and the Michigan polarized-proton target, we have studied the one-spin and two-spin asymmetries of pion and proton production in the inclusive reactions p up arrow + p up arrow → p + Anything, and p up arrow + p up arrow → pi⁺ + Anything at P_lab = 6, 11.75, and 12.75 GeV/c. We observed experimental one-spin and two-spin asymmetries by scattering the polarized-proton beam from our polarized-proton target in each of the four possible initial spin states. These inclusive one-spin and two-spin asymmetries were calculated using the measured experimental spin asymmetries and three types of background measurements taken at P_lab = 6 and 11.75 GeV/c. We varied the transverse momentum P_{perpendicular}) of the outgoing pion or proton from 0.71 to 1.55 GeV/c, and Feynman x variable from -0.08 to 0.67

[en] We report updated analysis results on an np elastic experiment at LAMPF and a pp experiment at the ZGS. We have measured two np spin asymmetry parameters, C_LL and C_SL, at beam energies 500, 650, and 800 MeV. The c.m. scattering angles of neutrons measured ranged from 80⁰ through 180⁰. We observed very large C_LL at backward angles for the first time. The pp experiment at the ZGS was a measurement of the difference between the pp total cross sections for parallel and antiparallel longitudinal spin states at beam momenta 2.75, 2.92, 3.25, 3.75, and 4.00 GeV/c. These results reveal possible new structures in this momentum range. Masses for these structures are about 2700 and 2900 MeV. (orig.)

[en] YBa₂Cu₄O₈ (124) is synthesized at ambient pressure condition using citrate pyrolysis precursor method, and the weakly sintered 124 ceramics are studied by both SEM observation and ac magnetization measurement. Such ceramics can be regarded as a system of weak-coupled super fine grains, so that we may study experimentally the intergrain superconductive phase transition considering the effects of mesoscopic sintered structure. For this purpose, several specimens at different treatment time stage in the sintering process are examined. As the sintering is advanced, very small grains are fused into larger ones and the adjacent large grains tend to be fused at their interface. From magnetic measurements, the ceramics are equally confirmed to be weak-coupled grain systems which show the intergrain ordering at each T_c2 determined consistently by sintering temperature. Utilizing the series of ceramics, we will be able to study the intergrain ordering further systematically

[en] Nitrogen (N) ions having energy as low as 20 eV were impinged onto the epitaxially growing GaAs surface using combined ion beam and molecular beam epitaxy (CIBMBE) method. Experiments were made as a function of N ion acceleration energy (E/sub a/) and N/sub +/ ion beam current density (I/sub N). E/sub a/ was varied from 20 eV to 30 keV and IN from 900 pA/cm2 to 75 nA/cm2. GaAs growth rate was fixed to 1 mm/h. Photoluminescence (pol) spectra at 2 k exhibited the formation of two sharp emissions at 1.58 eV(x) and 1.495 eV (x2), that are described to the emissions of excitons bound to isolated N atoms. The results show that nitrogen (n) atom in GaAs becomes optically active as an isoelectronic impurity. For samples impinged with relatively high IN, a broad emission together with multiple sharp ones was observed when furnace annealing at 750 degree centigrade was made for the impinged samples. These emissions were found to be due to excitons bound to nitrogen-nitrogen (N-N) pairs. (author)

[en] We propose a new method to significantly increase the quantum efficiency of a photomultiplier tube by employing a multi-photocathode and a mirror to produce photoelectrons by reusing photons transmitted by a single photocathode. In order to estimate the expected performance of the new photomultiplier, we studied the spectral responses of the reflectance, transmittance, and quantum efficiency of a K₂CsSb photocathode as a function of the wavelength of incident light. A large enhancement of the quantum efficiency is expected in the regions between λ=280 and 650 nm. (author)

[en] The spin-flop behavior of the magnetization and the magnetostrictive change associated with spin-flop transition are clearly observed in Tb-Fe/Fe multilayers. It is found that the easy axis of the Tb-Fe thin film changes into in-plane from the perpendicular direction by multilayering with Fe and a large magnetostriction value can be obtained around the Laves phase composition by utilizing the exchange coupling at interfaces

[en] L1₀ ordered FePt(0 0 1) thin films were prepared by alternating Fe and Pt monatomic layers on stepped Pt(0 0 1) surfaces at reduced temperature. The clear enhancement of coercivity has been observed due to the introduction of steps, which is considered to contribute to pinning domain walls

[en] Weakly sintered ceramic samples of YBa₂Cu₄O₈ (124) are prepared as systems of Josephson-coupled sub-micron grains, with varying sintering time. The obtained ceramic systems are studied by observing fundamental and harmonic magnetic responses. Each specimen shows characteristic temperature dependence of the responses caused by intergrain ordering. The ordering temperature estimated by singular peak of the nonlinear response changes consistently with the sintering time, indicating that the coupling strength is systematically changed. Furthermore, dual anomalies of the nonlinear response are found. The results suggest that two different origins of nonlinear response inhere in the intergrain ordering

[en] In-plane magnetized FePt films were prepared on MgO (1 1 0) single crystalline substrates by sputter-deposition, and the effects of a buffer layer and substrate temperature during deposition (T_s) on the formation of the L1₀ ordered structure have been investigated. From the X-ray diffraction patterns, the FePt (1 1 0) and (3 3 0) superlattice peaks of L1₀ phase have been clearly observed for the FePt thin film with an Au buffer layer deposited at T_s=300 deg. C. High degree of chemical order (S=0.7±0.1) have been achieved, leading to the large uniaxial magnetic anisotropy K_u of 2.4x10⁷ erg/cm³ with the easy axis along an in-plane direction