[en] The Fermilab HyperCP (E871) experiment collected on the order of 10¹⁰ hyperon decays. Based on an analysis of the data set collected in 1999 run, we will report on the observation of events with reconstructed masses consistent with that of Σ⁺ assuming the final state pμ⁺μ^-. If the observed events are the decay Σ⁺->pμ⁺μ^-, then they would be the first evidence of this decay. Other possible interpretations of the observed events will also be discussed

[en] In this paper, two issues in the FSS iteration method, i.e., the waiting time for surface source data and the variance biases in local tallies are investigated for the domain decomposed, 3-D continuous-energy whole-core calculation. The fission sources are provided as usual, while the surface sources are provided by banking MC particles crossing local domain boundaries. The surface sources serve as boundary conditions for nonoverlapping local problems, so that each local problem can be solved independently. In this paper, two issues in the FSS iteration are investigated. One is quantifying the waiting time of processors to receive surface source data. By using nonblocking communication, 'time penalty' to wait for the arrival of the surface source data is reduced. The other important issue is underestimation of the sample variance of the tally because of additional inter-iteration correlations in surface sources. From the numerical results on a 3-D whole-core test problem, it is observed that the time penalty is negligible in the FSS iteration method and that the real variances of both pin powers and assembly powers are estimated by the HB method. For those purposes, three cases; Case 1 (1 local domain), Case 2 (4 local domains), Case 3 (16 local domains) are tested. For both Cases 2 and 3, the time penalties for waiting are negligible compared to the source-tracking times. However, for finer divisions of local domains, the loss of parallel efficiency caused by the different number of sources for local domains in symmetric locations becomes larger due to the stochastic errors in source distributions. For all test cases, the HB method very well estimates the real variances of local tallies. However, it is also noted that the real variances of local tallies estimated by the HB method show slightly smaller than the real variances obtained from 30 independent batch runs and the deviations become larger for finer divisions of local domains. The batch size used for the HB method may not be large enough to accurately estimate the real variance in this test problem. In conclusion, the waiting time for surface source data is negligible in the FSS iteration method, and the loss of parallel efficiency caused by the different number of sources can be reduced by the source splitting scheme discussed.

[en] The synchrotron-radiation interferometer has been employed to measure the beam size in the storage ring at the 2.5 GeV Pohang Light Source [PLS]. We discuss the optical system of the interferometer and analysis methods to measure the beam size. The PLS has used a Min/Max method to measure the beam size in the ring. In our studies, we also investigated ways in which to optimize the measured results on the beam sizes in the vertical and the horizontal directions by using fitting methods with both Mathematica and Root. We examined the variations in the background by passing time and their effects on the measured beam sizes. In this paper, we present methods for analyzing the measured data that result in improvement the measurement of the beam size in the PLS.

[en] Nano powders of CaMoO₄ were synthesized by using the precipitation method, and the obtained powders were dried inside a vacuum oven at 120 °C. The phases of powders were analyzed by using X-ray diffraction (XRD), which revealed that CaMoO₄ was free from any extra phases. The surface morphologies of the powders were studied by using transmission electron microscopy (TEM), and the average particle sizes were quite small, being in the range of 7 nm. The optical properties were characterized by using ultraviolet-visible (UV-vis) absorption spectroscopy and the optical energy band gap was found to be 5.51 eV. The fluorescence decay time and the luminescence spectrum of the sample were measured under the excitation by Laser (266 nm), X-ray and proton sources. The obtained results were compared with the CaMoO₄ bulk crystal and sintered powder obtained from the solid state reaction.

[en] The NEOS detector take data from August 2015 to May 2016. The energy resolution of the detector is about 5% at 1 MeV and the ratio of signal to background is about 23. PSD is used to reduce backgrounds and it reduces more than 70% of backgrounds. The prompt energy spectrum was compared to the two models and the 5 MeV excess is first confirmed at short baseline. There is no strong evidence of light sterile neutrino with 3 + 1 hypothesis and region of low mass squared difference $\mathrm{\Delta <!--\; ??\; -->}{m}_{41}^2$ in allowed region of Reactor Anti-neutrino Anomaly[1] is disfavored. (paper)