Identification of zonal flows in a toroidal plasma

This Letter presents experimental confirmation of the presence of zonal flows in magnetically confined toroidal plasma using an advanced diagnostic system--dual heavy ion beam probes. The simultaneous observation of an electric field at two distant toroidal locations (approximately 1.5 m apart) in the high temperature (approximately 1 keV) plasma provides a fluctuation spectrum of electric field (or flow), a spatiotemporal structure of the zonal flows (characteristic radial length of approximately 1.5 cm and lifetime of approximately 1.5 ms), their long-range correlation with toroidal symmetry (n=0), and the difference in the zonal flow amplitude with and without a transport barrier. These constitute essential elements of turbulence-zonal flow systems, and illustrate one of the fundamental processes of structure formation in nature.     

Near-threshold diffractive psi-meson photoproduction from the proton

Photoproduction of a phi meson on protons was studied by means of linearly polarized photons at forward angles in the low-energy region from threshold to Egamma = 2.37 GeV. The differential cross sections at t = -|t|min do not increase smoothly as Egamma increases but show a local maximum at around 2.0 GeV. The angular distributions demonstrate that phi mesons are photoproduced predominantly by helicity-conserving processes, and the local maximum is not likely due to unnatural-parity processes.     

Modified micro-space using self-organized nanoparticles for reduction of methylene blue

By using silica layers bound to the surface of the inner wall of the microchannel via a self-assembly technique which relies on capillary forces to organize the colloids, TiO2 particles were attached to the inner surface of a microcapillary. The reduction rate of methylene blue increased by more than 150 times in the SiO2/TiO2 modified micro-space compared to that in a batch system.     

Real-time capturing of the nuclear wave-packet shape in self-trapped excitons

We measured the time evolutions of the luminescence spectra in a quasi-1D halogen-bridged platinum complex [Pt(en)(2)][Pt(en)(2)Br(2)](ClO4)(4) with a 50 fs resolution up-conversion spectroscopy and succeeded in real-time visualization of the shape of the wave packet (WP) propagating on the adiabatic potential surface of a self-trapped exciton. The behavior of the WP is in excellent agreement with a calculation based on a harmonic oscillator. We have found that the damping of the WP oscillation is highly nonexponential.     

Calculation of the scattering amplitude from discrete eigenvalues

We show that the scattering amplitude for a target with spherical symmetry can be directly calculated from the discrete eigenvalues of the corresponding stationary wave equation solved under an absorbing boundary condition, and thus uncover a direct connection between the scattering amplitude and the wave number spectrum. As an illustration, we apply this approach to the scattering of an electromagnetic wave by an array of dielectric slabs and find the transmission coefficient of the array to be completely determined by the spacing between adjacent eigenvalues.     

Electron–hole liquid formation by exciton and biexciton resonant excitation in CuCl

The dynamics of a cold photoexcited electron–hole system created by resonant excitation with picosecond optical pulses are studied by time-resolved emission and pump–probe measurements. A rapid build-up of strong metallic reflection in the mid-infrared region was observed, which indicates the creation of electron–hole plasma via the exciton or biexciton Mott transition. Transient reflection spectra clearly show the transformation of high-density electron–hole plasma into a metallic colloid-like state within 10 ps. In the meantime, broad plasma emission turns to a narrow emission band, in which the spectral profile does not change within several tens of picoseconds. These features in the emission spectra disappear when switched to the band-to-band excitation. An analysis of the reflection and emission spectra reveals that the density of metastable electron–hole liquid is as high as 10²⁰ cm⁻³. This indicates that the plasma formation via the Mott transition is crucial to eliminate excess heating for reaching the low-temperature states of an electron–hole ensemble.     

Structural fluctuations in argon and gold microclusters

A set of extensive molecular dynamics simulations of clusters of 79 argon and gold atoms is performed to investigate structural fluctuations in microclusters. Within a finite range of total energy, the cluster exhibited structural fluctuations between solid-like and liquid-like states and among different solid-like states. Based on the simulations, it may be concluded that the thermal expansion of the cluster initiates the structural fluctuations. The qualitative features are the same for argon and gold microclusters.     

Relations for molecular integrals of relativistic interactions

Relations are derived which connect the molecular integrals of variation of electron mass from relativity, spin—orbit interaction, orbit—orbit interation and spin—spin interaction with the overlap, the nuclear attraction and the electron repulsion integrals.