A spectrometer system was constructed for measurement of transient species in flames by absorption of ultraviolet radiation. The output of a xenon arc lamp was used as the source of radiation, which was focused through the flame and onto a monochromator equipped with an intensified silicon diode array detector. The system was used to measure absorption by hydroxyl (OH) radical around 306 nm in ...

In this research zinc oxide (ZnO) nano-crystalline powders were prepared by sol-gel method using zinc acetate. The ZnO nanoparticles were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), ultraviolet-visible (UV-Vis), Fourier transform infra-red (FT-IR) and energy dispersive X-ray (EDX) spectroscopy. The structure of nanoparticles was studied using XRD pattern. The c...

The responsivity of an extreme-ultraviolet transmission grating spectrometer with silicon photodiode detectors was measured with synchrotron radiation. The spectrometer was designed to record the absolute radiation flux in a wavelength bandpass centered at 30 nm. The transmission grating had a period of 200 nm and relatively high efficiencies in the +1 and the -1 diffraction orders that were di...

The Fourier Transform Ultraviolet Spectrometer (FTUVS) instrument has recorded a long-term data record of the atmospheric column abundance of the hydroxyl radical (OH) using the technique of high resolution solar absorption spectroscopy. We report new efforts in improving the precision of the OH measurements in order to better model the diurnal, seasonal, and interannual variability of odd hydr...

A systems approach in which computer automation is applied to a vacuum ultraviolet spectrometer and auxiliary components is described. The errors associated with the measurement of gaseous absorption coefficients in the vacuum ultraviolet are considered. The presence of scattered light introduces large errors particularly at those wavelengths where the source used is characterized by low intens...

We report on EUV spectroscopic observations of the B bright giant ǫ CMa made during the ORFEUS-SPAS II mission. We assess the performance of the instrument in the EUV and find that the effective area is roughly three times that of the EUVE long wavelength spectrometer and that the spectral resolution is λ/∆λ ≈ 1250. We identify most of the features, qualitatively compare different models, and e...