We demonstrate a single shot two-dimensional grating-based X-ray phase-contrast imaging using a synchrotron radiation source. A checkerboard designed phase grating for π phase modulation at 17 keV and 35 keV, and a lattice-shaped amplitude grating with a high aspect ratio to shield X-rays up to 35 keV were fabricated. A Fourier analysis of Moiré fringe generated by the gratings was introduced to obtain the two-dimensional differential phase-contrast image with a single exposure. The results show that soft tissues and cartilages of a chicken wing sample are clearly seen with differential phase variation in two-dimensional directions. Using this method not only the whole of an object but also only an inner part of the object can be imaged.

A Talbot-Lau interferometer using two-dimensional gratings and a conventional x-ray tube has been used to investigate a phase-contrast imaging technique that is sensitive to phase gradients in two orthogonal directions. Fourier analysis of Moiré fringe patterns was introduced to obtain differential phase images and scattering images from a single exposure. Two-dimensional structures of plastic phantoms and characteristic features of soft tissue were clearly obtained at 17.5 keV. The phase-stepping technique was also examined to investigate the spatial resolution of different phase retrieval methods. In the presented setup we found that the choice of phase retrieval method made little difference in image blur, and a large effective source size was found to give a high intensity in the image plane.

Carbon nanowalls (CNWs) are synthesized under pure methane gas (CH 4 ) using helicon plasma-enhanced chemical vapor deposition. CH 4 in the helicon discharge is effectively dissociated to hydrogen atoms and hydrocarbon radicals, resulting in the formation of CNWs on a Ni substrate only from CH 4 . CNWs are grown up at a high growth rate of 18 mm/h.

We investigated characteristics of a density peak observed in a magnetic field B 0 lower than 100 G in the case of using helicon plasma sources with particular wavelength. For B 0 > 30 G, the antenna launches an electromagnetic wave as a slow wave, the phase velocity of which becomes close to the electron thermal velocity under the density-peak condition for various gas pressures. The Landau damping frequency is higher than the electron-neutral and the electron-ion collision frequencies, which indicates that the wave produces the plasma via Landau damping at low B 0 . The wavelengths estimated from the density n e and B 0 for the density peaks agree with those of the electromagnetic field generated by helicon antennas of various lengths. The measured density is found to vary under the condition of the agreement between wavelengths of the propagating wave and the antenna-excited field during the density increase. One of the causes of the density peak appearing as a function of B 0 is considered to be the wavelength variation and the corresponding change of phase velocity of the slow wave which is enabled to propagate in the plasma by the introduction of B 0 .

Nitrogen–C60 compounds such as azafullerene (C59N) and nitrogen-atom-encapsulated fullerene (N@C60) are produced by implanting nitrogen ions into C60 thin films on a substrate immersed in an electron cyclotron resonance plasma under a mirror magnetic field. Each compound is found to be synthesized, depending on the ion energy provided by the potential difference between the substrate and the plasma. The optimum energy for C59N synthesis is approximately 40–50 eV, and the amount of C59N decreases in an ion energy range larger than 50 eV. In contrast, an ion energy larger than 20 eV is required for N@C60 synthesis.