A new tracking detector, scintillating track image camera (SCITIC) was used for hyperon-scattering experiments. Since the hyperon lifetimes are short, the low-energy hyperon-nucleon scattering can be studied only with a track detector used as an active target. The present experiment has shown that the SCITIC is a promising detector for the hyperon scattering experiments. Polarized hyperons AE þ were produced through pð þ ; K þ ÞAE þ reactions with a 1.6 GeV/c pion beam on a liquid scintillator of the active target. Three sets of SCITIC were used to record the pictures of AE þ production and scattering. A kaon spectrometer was used to trigger the SCITIC with a signal of kaon from the reaction. Left/right asymmetries of the AE þ p scattering were determined through analyses of the pictorial data, and the results were in accordance with a quark-model prediction that the asymmetry was large in the AE þ p scattering while it was small in the ÃN case.

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We have observed the formation of the Cu centers in p-type Si crystals diffused with dilute Cu between 400 and 1000 °C by deep-level transient spectroscopy (DLTS) and photoluminescence methods. For the samples diffused below 800 °C, a DLTS Cu center denoted as the CuDLB center was the main component and was almost uniformly distributed in the bulk. For the samples diffused above 800 °C, a precipitate-related Cu species was the main component at the surface, and low-concentration CuDLB centers and another precipitate-related species were the main components in the bulk. We attributed the inhomogeneous depth profiles of the Cu species in the samples diffused above 800 °C to the out-diffusion of Cu atoms and their precipitation near the sample surface. The dissociation product of the CuDLB center denoted as the CuDLA center was occasionally produced by the diffusion of Cu below 600 °C due to the precipitation of interstitial Cu. On the basis of these observations, we discussed the formation kinetics and structures of the CuDLB and CuDLA centers.

Evolution of intrinsic defects (interstitials or vacancies) formed by implanting with protons and copper ions in silicon crystals and then annealing the crystals at temperatures from 100 to 800 °C was investigated by photoluminescence (PL) measurements. For samples annealed below 400 °C, only the well known W and I3 center peaks were observed for both proton and copper implantations. Several no-phonon PL peaks (at least six), that were inferred to be due to interstitial clusters, were newly evolved between 1.2 to 1.4 μm for samples heavily implanted with both protons and copper ions after annealing between 500 and 600 °C, indicating the existence of several self-interstitial clusters having a stability between that of the W center and the {311} defects. From the dependences of the PL intensities of these new peaks on the densities of the displaced atoms formed by implantations and on the annealing temperatures, these clusters were thought to be composed of larger numbers of self-interstitials than the W center. In addition to these peaks (the W, I3, and new centers), several broad peaks seemingly due to plural origins were observed after annealing the heavily implanted samples from room temperature to 600 °C, however, they completely vanished after annealing at 700 °C. Evolution of the PL peak located at 1.376 μm and known to be due to the {311} defects was not observed after the annihilation of the preceding peaks that are presumed to be the precursors of the {311} peak.

The differential incoherent scattering cross sections of 320 kev photons by K-shell electrons of lead, tantalum and samarium are experimentally determined employing a fast-slow coincidence scintillation spectrometer by the degraded photon Kx-ray coincidence technique at angles of scattering 45", 60", 90" and 110'. T h e results are compared with the computed values and the trends of the incoherent scattering function are discussed.