A compact optical setup for quantitative and spatially resolved measurement of atomic alkali concentration in combustion is demonstrated. Tunable diode laser absorption spectroscopy and laser-induced fluorescence are ...A compact optical setup for quantitative and spatially resolved measurement of atomic alkali concentration in combustion is demonstrated. Tunable diode laser absorption spectroscopy and laser-induced fluorescence are combined using a single continuous wave diode laser to measure the line-integration concentration and the relative distribution simultaneously, thereby obtaining the absolute concentration distribution along the laser beam. The results indicate the good performance of this method for one-dimensional quantitative measurement.展开更多
A novel method based on wavelength-multiplexed line-of-sight absorption and profile fitting for nonuniform flow field measurement is reported. A wavelength scanning combing laser temperature and current modulation WMS...A novel method based on wavelength-multiplexed line-of-sight absorption and profile fitting for nonuniform flow field measurement is reported. A wavelength scanning combing laser temperature and current modulation WMS scheme is used to implement the wavelength-multi- plexed-profile fitting method. Second harmonic （2f） signal of eight H20 transitions features near 7,170 cm^-1 are measured in one period using a single tunable diode laser. Spatial resolved temperature distribution upon a CH4/air premixed flat flame burner is obtained. The result validates the feasibility of strategy for non-uniform flow field diagnostics by means of WMS-2f TDLAS.展开更多
The remaining challenges, confronting high-power microwave （HPM） sources and pulsed power generators, stim- ulate the developments of robust relativistic electron beam sources. This paper presents a carbon fibre cat...The remaining challenges, confronting high-power microwave （HPM） sources and pulsed power generators, stim- ulate the developments of robust relativistic electron beam sources. This paper presents a carbon fibre cathode which is tested in a single pulsed power generator. The distribution and the development of cathode plasma are observed by time-and-space resolved diagnostics, and the uniformity of electron beam density is checked by taking x-ray images. A quasistationary behaviour of cathode plasma expansion is observed. It is found that the uniformity of the extracted electron beam is satisfactory in spite of individual plasma jets on the cathode surface. These results show that carbon fibre cathodes can provide a positive prospect for developing a high-quality electron beam.展开更多
We show that Fourier-plane imaging in conjunction with the Kretschmann–Raether configuration can be used for measuring polariton dispersion with spatial discrimination of the sample, over the whole visible spectral r...We show that Fourier-plane imaging in conjunction with the Kretschmann–Raether configuration can be used for measuring polariton dispersion with spatial discrimination of the sample, over the whole visible spectral range.We demonstrate the functionality of our design on several architectures, including plasmonic waveguides, and show that our new design enables the measurement of plasmonic dispersion curves of spatially inhomogeneous structures with features as small as 3 μm, in a single shot.展开更多
基金Supported by the National Natural Science Foundation of China under Grant Nos 91541119 and 91541203
文摘A compact optical setup for quantitative and spatially resolved measurement of atomic alkali concentration in combustion is demonstrated. Tunable diode laser absorption spectroscopy and laser-induced fluorescence are combined using a single continuous wave diode laser to measure the line-integration concentration and the relative distribution simultaneously, thereby obtaining the absolute concentration distribution along the laser beam. The results indicate the good performance of this method for one-dimensional quantitative measurement.
基金supported by the National Natural Science Foundation of China(10772188)
文摘A novel method based on wavelength-multiplexed line-of-sight absorption and profile fitting for nonuniform flow field measurement is reported. A wavelength scanning combing laser temperature and current modulation WMS scheme is used to implement the wavelength-multi- plexed-profile fitting method. Second harmonic （2f） signal of eight H20 transitions features near 7,170 cm^-1 are measured in one period using a single tunable diode laser. Spatial resolved temperature distribution upon a CH4/air premixed flat flame burner is obtained. The result validates the feasibility of strategy for non-uniform flow field diagnostics by means of WMS-2f TDLAS.
基金Project supported by the National High Technology Research and Development Program of China
文摘The remaining challenges, confronting high-power microwave （HPM） sources and pulsed power generators, stim- ulate the developments of robust relativistic electron beam sources. This paper presents a carbon fibre cathode which is tested in a single pulsed power generator. The distribution and the development of cathode plasma are observed by time-and-space resolved diagnostics, and the uniformity of electron beam density is checked by taking x-ray images. A quasistationary behaviour of cathode plasma expansion is observed. It is found that the uniformity of the extracted electron beam is satisfactory in spite of individual plasma jets on the cathode surface. These results show that carbon fibre cathodes can provide a positive prospect for developing a high-quality electron beam.
基金Israel Science Foundation(ISF)(1993/13)FP7 People:Marie-Curie Actions(PEOPLE)(PCIG12-GA-2012-618921)Wolfson Family Charitable Trust(WFCT)(PR/ec/20419)
文摘We show that Fourier-plane imaging in conjunction with the Kretschmann–Raether configuration can be used for measuring polariton dispersion with spatial discrimination of the sample, over the whole visible spectral range.We demonstrate the functionality of our design on several architectures, including plasmonic waveguides, and show that our new design enables the measurement of plasmonic dispersion curves of spatially inhomogeneous structures with features as small as 3 μm, in a single shot.
