The structure of the shower disk observed at Mt. Norikura

The structure of the EAS shower disk, the arrival time distribution of charged particles at the core of the small or middle size shower, is measured at Mt. Norikura in Japan. Four fast scintillation counters with an area of 0.25 sq m and a fast trigger system are added to the Mt. Norikura EAS array for the study

Fast scintillation counter system and performance

An experimental study of the fast scintillation counter (FS) system to observe a shower disk structure at Mt. Norikura is described, especially the system performance and a pulse wave-form by a single charge particles. The photomultiplier tube (PT) pulse appears at the leading edge of the main pulse. To remove this PT-pulse from the main pulse, the frame of the scintillator vessel was changed. The fast triggering system was made to decrease the dead time which came from the use of the function of the self triggering of the storage oscilloscope (OSC). To provide a new field on the multi-parameter study of the cosmic ray showers, the system response of the FS system also improved as a result of many considerations

Comparison of absolute intensity between EAS with gamma-families and general EAS at Mount Norikura

Gamma-families with total energy greater than 10 TeV, found in the EX chamber which was cooperated with the EAS array were combined with EAS triggered by big bursts. The absolute intensity of the size spectrum of these combined EAS was compared with that of general EAS obtained by AS trigger. The EAS with sizes greater than 2x1 million were always accompanied by gamma-families with sigma E sub gamma H 10 TeV, n sub gamma, H 2 and Emin=3 TeV, although the rate of EAS accompaning such gamma-families decreases rapidly as their sizes decrease

Fabrication of ZnSnP(2) thin films by phosphidation

ZnSnP(2) is a promising candidate as a solar absorbing material consisting of earth-abundant and low-toxic elements. In this study, the phosphidation method, where co-sputtered Zn–Sn thin films react with phosphorus gas, was adopted for fabricating ZnSnP(2) thin films. To establish the conditions for producing ZnSnP(2) thin films, we investigated the influence of phosphidation temperature on the product phases, and interpreted the experimental results using chemical potential diagrams of the Zn–Sn–P system. ZnSnP(2) thin films with a single phase were obtained by phosphidation at 500 °C under a phosphorus vapor pressure of 10[−2] atm. However, formation of ZnSnP(2)protrusions was observed on the surface of the thin films. Based on the experimental results and the chemical potential diagrams, it is indicated that un-reacted liquid Sn particles reacted with Zn and phosphorus gas to form ZnSnP(2) protrusions in a manner similar to the vapor-Liquid-Solid growth mode

Search for non-random feature in arrival times of air showers

We have searched for non-random components in arrival times of air showers of mean energy of 1 PeV. By counting the number of air showers observed within time windows of 20-60 minutes, we find small deviation of air shower data from the conventional view of uniformly random cosmic ray injection. The arrival directions of the non-random events concentrate at the direction of the Galactic plane. Though the significance of these events is not so high because of the lack of statistics, they may be induced by sporadic non-random injection of ultra-high energy γ-rays from the Galactic plane

Increased Variability of Thailand\u27s Chao Phraya River Peak Season Flow and Its Association With ENSO Variability: Evidence From Tree Ring δ\u3csup\u3e18\u3c/sup\u3eO

We present a statistically robust reconstruction of Thailand\u27s Chao Phraya River peak season streamflow (CPRPF) that spans the 202 years from 1804 to 2005 CE. Our reconstruction is based on tree ring δ18O series derived from three Pinus merkusii sites from Laos and Thailand. The regional δ18O index accounts for 57% of the observed variance of CPRPF. Spatial correlation and 21‐year running correlation analyses reveal that CPRPF is greatly influenced by regional precipitation variations associated with the El Niño–Southern Oscillation (ENSO). Periods of enhanced and reduced ENSO activity are associated with strong and weak ENSO‐streamflow correlation, respectively. At the longer timescale, the Pacific Decadal Oscillation (PDO) appears to modulate the ENSO‐streamflow correlations, with the most extreme flood events along the Chao Phraya River occurring during periods of increased frequency of La Niña events that coincide with extended cold phases of the PDO. The CPRPF reconstruction could aid management planning for Thailand\u27s water resources

Evolution of the dipole polarizability in the stable tin isotope chain

The dipole polarizability of stable even-mass tin isotopes 112,114,116,118,120,124 was extracted from inelastic proton scattering experiments at 295 MeV under very forward angles performed at RCNP. Predictions from energy density functionals cannot account for the present data and the polarizability of 208Pb simultaneously. The evolution of the polarizabilities in neighboring isotopes indicates a kink at 120Sn while all model results show a nearly linear increase with mass number after inclusion of pairing corrections.Comment: 10 pages, 6 figures, submitted to Phys. Lett.