[en] Using a 15 keV argon ion beam to impact a polycrystalline aluminum target, the intensities of the sputtered Al particles and the backscattered projectiles in different angle of incidence were measured. The data showed that the angular distributions of Ar and Al particles were quite different. Due to the intensity of sputtered target atoms are strongly correlated to the sputtering yields of the target atoms. The SRIM-simulation program was employed to obtain the sputtering yields of Al atoms. The angular distributions of sputtered Al particles and sputtering yields were compared each other and revealed that both of them were in a fairly good agreement. From the results of simulated sputtering yields and backscattered Ar particles, we conclude that the structure of the target and a linear collision cascade processes determine the angular distribution of the sputtered target atoms in this measurement

[en] We investigated the distortion effects on the spin transfer coefficient D_nn for the intermediate energy (p,n) charge exchange reactions leading to the Gamow-Teller resonance in the continuum region. When the distortion is included, the imaginary parts of both the central and the tensor direct contributions are significantly changed. Also, the magnitude of T₀₀ becomes smaller, which results in larger D_nn values. We also found that when the distortion is included the phase difference between T₀₀ and T₂₀ in the complex plane remains almost the same for different Q-values

[en] A focused 15 keV argon ion beam was used to bombard iced targets, CO₂ and H₂O (at temperature (27 K). The sputtered particles were analyzed by a quadrupole mass spectrometer (QMS). The purpose of the experiment was to measure the percentage of the sputtered particles that originated from the impact sites on the iced targets. Some of the particles that were not induced from ion-iced-CO₂ interaction include, for instance, CO, O and C; these were produced during the disintegration by the QMS of pure CO₂, which is copiously sputtered in ion-iced-CO₂ interaction. The analyzed data will be useful for understanding the chemical reaction in ion-molecule interactions

[en] We present a measurement of the time-dependent CP violation parameters for B⁰ → D*⁺D*^-K_s⁰ and B⁰ → J/ψK_s⁰ decays obtained from the distribution of proper time intervals between the two B decays. These results are obtained from a data sample of BB pairs collected at the Υ (4S) resonance with the Belle detector at the KEKB asymmetric e⁺e^- collider. For B⁰ → D*⁺D*^-K_s⁰, we find no evidence for direct or mixing-induced CP violation, and in a fit sensitive to cos2φ₁, no conclusion can be drawn regarding its sign with current statistics. For B⁰ → J/ψπ⁰, we find no evidence for direct CP violation and measure mixing-induced CP violation consistent with Standard Model expectations, with a 2.4σ significance

[en] While the thermal performance of existing insulation materials have been determined by blister gases, the thermal performance of future insulation materials will be dependent on the cell size and independent foam content as we use eco-friendly blister gases with a higher thermal conductivity. However, with the current technology we are only able to guess the whole cell size and independent foam content through SEM applied 2D fragmentary scanning but are still far from the level of accurate cell structure data extraction. Under this situation, we utilized X-ray CT scanned 3D images to identify and shape the cell structure and proposed a method of inferring the whole distribution and independent foam content as accurately as possible. According to X-ray CT scanning images and SEM images, the shape was similar but according to tracer applied CT scanning images, the cell size distribution was 380∼400 pm within the range of the general insulation diameter distribution which had the highest reliability. As for extrusion foaming polystyrene, we need additional image processing to identify the independent foam content as its density is too low. So, it is recommended to raise the 3D cell structure completeness of XPS by improving the scanning accuracy. (paper)

[en] The multi-stage effect has been revisited through growing carbon nanotube field emitters on single strand carbon fiber with a thickness of 11 μm. A prepared linear electron source exhibits a turn-on field as low as 0.4 V μm^-1 and an extremely high field enhancement factor of 19 300, when compared with those results from reference nanotube emitters grown on flat silicone wafer; 3.0 V μm^-1 and 2500, respectively. In addition, we introduce a novel method to grow nanotubes uniformly around the circumference of carbon fibers by using direct resistive heating on the continuously feeding carbon threads. These results open up not only a new path for synthesizing nanocomposites, but also offer an excellent linear electron source for special applications such as backlight units for liquid crystal displays and multi-array x-ray sources.

[en] Tritium (T) distributions on tungsten (W)-coated plasma-facing tiles used in the third ITER-like wall campaign (2015-2016) of the Joint European Torus (JET) were examined by means of an imaging plate technique and beta-ray induced x-ray spectrometry, and they were compared with the distributions after the second (2013-2014) campaign. Strong enrichment of T in beryllium (Be) deposition layers was observed after the second campaign. In contrast, T distributions after the third campaign was more uniform though Be deposition layers were visually recognized. The one of the possible explanations is enhanced desorption of T from Be deposition layers due to higher tile temperatures caused by higher energy input in the third campaign. (authors)

[en] We report improved measurements of time-dependent CP violation parameters for B⁰(B⁰)→J/ψπ⁰ decay. This analysis is based on 535x10⁶ BB pairs accumulated at the Υ(4S) resonance with the Belle detector at the KEKB asymmetric-energy e⁺e^- collider. From the distribution of proper time intervals between the two B decays, we obtain the following CP violation parameters S_J/ψπ⁰=-0.65±0.21(stat)±0.05(syst) and A_J/ψπ⁰=+0.08±0.16(stat)±0.05(syst),which are consistent with standard model expectations.

[en] Surface characterization of bulk tungsten tiles (W lamellae) used during the first campaign of JET with the ITER-Like Wall (JET-ILW) was performed by means of microscopy and tritium imaging techniques. This is the first report regarding very detailed structural studies of W lamellae from the JET-ILW divertor. A special feature of the W lamellae installed in JET is the intrinsic network of micro-cracks detected on surfaces of the as-manufactured material. Analyses of different W lamellae samples on the plasma-facing surface reveal two types of surface structures caused by plasma impact: areas with strong erosion and regions of mild plasma interaction. In regions of strong erosion, a thin modified layer (thickness of ∼20 nm) with a high density of defects including bubble-like structures has been formed. In addition, features indicating melting along edges of micro-cracks with the micro-scale plastic deformation have been identified. (topical issue article)

[en] Primary cosmic-ray elemental spectra have been measured with the balloon-borne Cosmic Ray Energetics And Mass (CREAM) experiment since 2004. The third CREAM payload (CREAM-III) flew for 29 days during the 2007–2008 Antarctic season. Energies of incident particles above 1 TeV are measured with a calorimeter. Individual elements are clearly separated with a charge resolution of ∼0.12 e (in charge units) and ∼0.14 e for protons and helium nuclei, respectively, using two layers of silicon charge detectors. The measured proton and helium energy spectra at the top of the atmosphere are harder than other existing measurements at a few tens of GeV. The relative abundance of protons to helium nuclei is 9.53 ± 0.03 for the range of 1 TeV/n to 63 TeV/n. This ratio is considerably smaller than other measurements at a few tens of GeV/n. The spectra become softer above ∼20 TeV. However, our statistical uncertainties are large at these energies and more data are needed.