Size resolved characteristics of urban and suburban bacterial bioaerosols in Japan as assessed by 16S rRNA amplicon sequencing.

To study the size-resolved characteristics of airborne bacterial community composition, diversity, and abundance, outdoor aerosol samples were analysed by 16S rRNA gene-targeted quantitative PCR and amplicon sequencing with Illumina MiSeq. The samples were collected using size-resolved samplers between August and October 2016, at a suburban site in Toyama City and an urban site in Yokohama City, Japan. The bacterial communities were found to be dominated by Actinobacteria, Firmicutes, and Proteobacteria.

Airborne Microbial Communities at High-Altitude and Suburban Sites in Toyama, Japan Suggest a New Perspective for Bioprospecting.

Airborne microorganisms, especially those at high altitude, are exposed to hostile conditions, including ultraviolet (UV) radiation, desiccation, and low temperatures. This study was conducted to compare the composition and abundance of airborne microorganisms at a high-altitude site, Mt. Jodo [2,839 m above mean sea level (AMSL)] and a suburban site (23 m AMSL) in Toyama, Japan.

Single field-of-view tomographic imaging of 3D impurity emission distribution in magnetized edge plasma of LHD.

A new tomographic scheme is proposed for reconstructing three dimensional (3D) impurity emission distributions from two dimensional (2D) measurements with a single field-of-view in the magnetized edge plasma in a Large Helical Device (LHD). The 2D image is obtained with a multi-channel fiber array spectrometer, which views the entire region of the edge stochastic magnetic layer of LHD, including divertor plates, divertor legs, the stochastic layer, and the last closed flux surface. The scheme introduces new regularization terms in the Lagrangian function, based on the transport feature in magnetized plasma that the transport parallel to the magnetic field lines is much faster than the transport across the magnetic field, thus assuming smooth distribution in the parallel direction.

A fast-time-response extreme ultraviolet spectrometer for measurement of impurity line emissions in the Experimental Advanced Superconducting Tokamak.

A flat-field extreme ultraviolet (EUV) spectrometer working in the 20-500 Å wavelength range with fast time response has been newly developed to measure line emissions from highly ionized tungsten in the Experimental Advanced Superconducting Tokamak (EAST) with a tungsten divertor, while the monitoring of light and medium impurities is also an aim in the present development. A flat-field focal plane for spectral image detection is made by a laminar-type varied-line-spacing concave holographic grating with an angle of incidence of 87°. A back-illuminated charge-coupled device (CCD) with a total size of 26.

Space-resolved 3 m normal incidence spectrometer for edge impurity diagnostics in the large helical device.

A space-resolved vacuum ultraviolet (VUV) spectroscopy using a 3 m normal incidence spectrometer has been developed to measure the impurity profile in the edge ergodic layer composed of stochastic magnetic field by which the edge plasma in the large helical device (LHD) is uniquely characterized. It vertically measures the spatial profile of VUV lines emitted from impurities in the wavelength range of 300-3200 Å. The wavelength interval, Δλ, which can be measured in a single discharge, is about 37 Å.

Space-resolved extreme ultraviolet spectroscopy free of high-energy neutral particle noise in wavelength range of 10-130 Å on the large helical device.

A flat-field space-resolved extreme ultraviolet (EUV) spectrometer system working in wavelength range of 10-130 Å has been constructed in the Large Helical Device (LHD) for profile measurements of bremsstrahlung continuum and line emissions of heavy impurities in the central column of plasmas, which are aimed at studies on Zeff and impurity transport, respectively. Until now, a large amount of spike noise caused by neutral particles with high energies (≤180 keV) originating in neutral beam injection has been observed in EUV spectroscopy on LHD. The new system has been developed with an aim to delete such a spike noise from the signal by installing a thin filter which can block the high-energy neutral particles entering the EUV spectrometer.

Radial profile measurement of electron temperature in edge stochastic magnetic field layer of LHD using intensity ratio of extreme ultraviolet line emissions.

Vertical profile of neon line emissions in 30-650 Å wavelength range has been observed in horizontally elongated plasma cross section of Large Helical Device (LHD). Intensity ratio between the neon line emissions is studied to measure the radial profile of electron temperature in the edge stochastic magnetic field layer of LHD. The edge temperature profile successfully obtained from the line ratio of NeVIII 2s-3p to 2p-3s transitions is compared with the simulation based on three-dimensional edge transport code.

Effect of high-energy neutral particles on extreme ultraviolet spectroscopy in large helical device.

Spectra measured by an extreme ultraviolet (EUV) spectrometer frequently suffer large spike noise when Large Helical Device is operated in low-density range (≤ 3 × 10(13) cm(-3)) with neutral beam injection (NBI). The spike noise completely disappears in electron cyclotron heating discharges. In order to examine the effect of NBI, a carbon filter with thickness of 150 nm was installed in the EUV spectrometer.

Absolute sensitivity calibration of vacuum and extreme ultraviolet spectrometer systems and Z(eff) measurement based on bremsstrahlung continuum in HL-2A tokamak.

A grazing-incidence flat-field extreme ultraviolet (EUV) spectrometer has been newly developed in HL-2A tokamak. Typical spectral lines are observed from intrinsic impurities of carbon, oxygen, iron, and extrinsic impurity of helium in the wavelength range of 20 Å-500 Å. Bremsstrahlung continuum is measured at different electron densities of HL-2A discharges to calibrate absolute sensitivity of the EUV spectrometer system and to measure effective ionic charge, Z(eff).

Two-dimensional measurement of edge impurity emissions using space-resolved extreme ultraviolet spectrometer in Large Helical Device.

A space-resolved extreme ultraviolet (EUV) spectrometer working in wavelength range of 50-500 Å has been developed to measure two-dimensional distribution of impurity spectral lines emitted from edge plasma of Large Helical Device (LHD), in which the magnetic field is formed by stochastic magnetic field with three-dimensional structure called ergodic layer. The two-dimensional measurement of edge impurity line emissions is carried out by scanning horizontally the observation chord of the space-resolved EUV spectrometer during single LHD discharge. Images of CIV (312.

Absolute intensity calibration of flat-field space-resolved extreme ultraviolet spectrometer using radial profiles of visible and extreme ultraviolet bremsstrahlung continuum emitted from high-density plasmas in Large Helical Device.

A precise absolute intensity calibration of a flat-field space-resolved extreme ultraviolet (EUV) spectrometer working in wavelength range of 60-400 Å is carried out using a new calibration technique based on radial profile measurement of the bremsstrahlung continuum in Large Helical Device. A peaked vertical profile of the EUV bremsstrahlung continuum has been successfully observed in high-density plasmas (n(e) ≥ 10(14) cm(-3)) with hydrogen ice pellet injection. The absolute calibration can be done by comparing the EUV bremsstrahlung profile with the visible bremsstrahlung profile of which the absolute value has been already calibrated using a standard lamp.

Z(eff) measurement using extreme ultraviolet bremsstrahlung emission in LHD.

Radial profile measurement of Z(eff) using visible bremsstrahlung (5300 Å) in the Large Helical Device (LHD) has often encountered difficulties because the intensity profile was largely deformed by the nonuniform visible bremsstrahlung emissions from the edge ergodic layer surrounding the core plasma. A space-resolved flat-field extreme ultraviolet (EUV) spectrometer has been newly adopted to measure the Z(eff) profile using the EUV bremsstrahlung continuum in the wavelength range of 70-75 Å. The EUV bremsstrahlung intensity profiles have been measured and checked for all the magnetic configurations with totally different magnetic field structures in the ergodic layer of LHD.

Space-resolved extreme ultraviolet spectrometer for impurity emission profile measurement in Large Helical Device.

A space-resolved extreme ultraviolet (EUV) spectrometer working in 60-400 A range has been developed to observe impurity emission profiles in core and edge plasmas of Large Helical Device (LHD). A flat focus is made for plane surface detector by using a varied line spacing holographic grating with an angle of incidence of 87 degrees. An excellent spectral resolution of 0.

Spectroscopic evaluation of three different gratings used for a flat-field extreme ultraviolet spectrometer to monitor Delta n=1 transitions from medium-Z impurities in 10-30 A.

Spectral characteristics of varied line spacing 2400 grooves/mm gratings used for a flat-field extreme ultraviolet spectrometer have been evaluated to monitor Delta n=1 (n=2-3) transitions from medium-Z impurities in 10-30 A, where many spectral lines from metallic impurities closely exist. For this purpose emission spectra of the Delta n=1 transitions from partially L-shell-ionized Ti and Fe have been measured in large helical device. At first, a ruled and a holographic grating were utilized for the comparative study.

Fast ion charge exchange spectroscopy measurement using a radially injected neutral beam on the large helical device.

An experimental technique to investigate fast ion confinement based on charge exchange spectroscopy of H(alpha)-light was applied to evaluate the confinement property of perpendicular fast ions in large helical device (LHD). Sensitivities of the H(alpha) spectra to the pitch angles of injected neutral beams (NBs) and these to the angle between the sight line of the measurement and NB injection path are examined. The energy dependence of the charge exchange cross section significantly affects the observed spectra since the driving NB is injected perpendicular to the magnetic field lines in the geometry of LHD.

Characteristics of an absolutely calibrated flat-field extreme ultraviolet spectrometer in the 10-130 A range for fusion plasma diagnostics.

A flat-field extreme ultraviolet (EUV) spectrometer with a nominal 2400 grooves/mm aberration-corrected ruled grating has been developed to analyze the emission spectrum in the wavelength range of 10 to 130 A from large helical device (LHD) plasmas. Spectral properties such as resolution, sensitivity, contribution of higher-order light, and background stray light have been studied using emission spectra mainly from intrinsic impurities, e.g.

Spectroscopic comparison between 1200 grooves/mm ruled and holographic gratings of a flat-field spectrometer and its absolute sensitivity calibration using bremsstrahlung continuum.

A flat-field extreme ultraviolet (EUV) spectrometer with a varied line spacing groove grating (1200 grooves/mm at grating center) has been developed to study the emission spectra from highly ionized medium Z impurities in large helical device (LHD). It covers a wavelength range of 50-500 A using a mechanically ruled grating, which was later replaced by a newly developed laminar-type holographic grating for comparative studies. Differences in spectral resolution, intensities of higher order spectra, and sensitivities of the spectrometer were studied between the two gratings by observing the emission spectra of LHD plasmas.