Angular distribution of individual γ-rays, emitted from a neutron-induced compound nuclear state via radiative capture reaction of 139 La(n,γ) has been studied as a function of incident neutron energy in the epithermal region by using germanium detectors.An asymmetry ALH was defined as (NL − NH)/(NL + NH), where NL and NH are integrals of low and high energy region of a neutron resonance respectively, and we found that ALH has the angular dependence of (A cos θγ + B), where θγ is emitted angle of γ-rays, with A = −0.3881 ± 0.0236 and B = −0.0747 ± 0.0105 in 0.74 eV p-wave resonance.This angular distribution was analyzed within the framework of interference between s-and p-wave amplitudes in the entrance channel to the compound nuclear state, and it is interpreted as the value of the partial p-wave neutron width corresponding to the total angular momentum of the incident neutron combined with the weak matrix element, in the context of the mechanism of enhanced parity-violating effects. Additionally we used the result to quantify the possible enhancement of the breaking of the time-reversal invariance in the vicinity of the p-wave resonance.

A: In this study, the germanium detector assembly, installed at the Accurate Neutron-Nuclear Reaction measurement Instruments (ANNRI) in the Material and Life Science Facility (MLF) operated by the Japan Proton Accelerator Research Complex (J-PARC), has been characterized for extension to the measurement of the angular distribution of individual γ-ray transitions from neutron-induced compound states. We have developed a Monte Carlo simulation code using the GEANT4 toolkit, which can reproduce the pulse-height spectra of γ-rays from radioactive sources and (n,γ) reactions. The simulation is applicable to the measurement of γ-rays in the energy region of 0.5-11.0 MeV. K: Detector modelling and simulations I, Gamma detectors

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Bulk-heterojunction organic thin-film solar cells incorporating gold and silver nanoparticles were fabricated and evaluated. These nanoparticles were embedded in the hole-transport layer of the solar cells. Plasmonic absorption peaks of isolated gold and silver nanoparticles were confirmed from extinction spectra even in the hole-transport material. The incorporation of gold and silver nanoparticles increased the photoelectric conversion efficiency of organic thin-film solar cells, whose enhancement ratio was further increased by mixing gold and silver nanoparticles.