C K-emission spectra were measured by an electron probe microanalyzer in which a lead stearate pseudocrystal was used as an analyzing element for the 2nd order spectrum of the C K band. Strong polarized emission spectra were obtained from single crystal surfaces of graphite when excited by electron beams perpendicular and parallel to the basal plane. A single crystal of diamond did not give any polarized spectra, which indicated no strong orientation of electronic orbitals in diamond. It was found that the spectrum of carbon black could be synthesized graphically by averaging the spectra of single crystals of graphite at perpendicular and parallel orientations. Thus, carbons with a graphitic arrangement however slight can be expected to give only one type of spectrum. The spectrum of carbon precursor was quite different from those of any other allotropes of carbon.

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This paper reports simple coaxial flashlamp-excited dye lasers developed and fabricated high power, frequency tunable light sources for use in a variety of spectroscopy and optical instrumentation systems such as laser radars and remote sensors. Optimum design parameters of the discharge tube length and the annular width are obtained. The operational performances used as a dye laser oscillator and an amplifier are investigated using Rhodamine 6G in ethanol and pure water-Ammonyx LO solvents. In the oscillator mode of operation, maximum output energy of about 400 mJ and energy conversion efficiency of 0.12% are realized. In the amplifier mode, effective output gain of 120 is measured and a stable synchronization of the flashlamp discharge with the oscillator laser is attained by utilizing simmer discharge technique. Higher pulse repetition rate and smaller laser beam divergence are possible by using pure water as a dye solvent than ethanol. No remarkable output degradation of the coaxial flashlamp is observed in excess of 1000 shots at 300J input energy.

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A construction of a light scattering spectrometer using the light beating method is described. In order to test the performance of this instrument, Rayleigh scattering spectra were observed for the polystyrene latex spheres suspended in water and the binary mixture of carbon disulfide and acetone (0.1 mole fraction of acetone). The half-widths of scattering spectra were reduced to the mutual diffusion coefficient for the binary mixture of tert-butanol (TBA) and water. The cooperative motion of TBA and water molecules is discussed on the basis of the concentration dependence of the mutual diffusion coefficient.

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A self-scanning linear photodiode array of 512 elements (National MEL-512KV) was mounted at the focal plane of a 25-cm monochromator instead of the exit slit. It is capable of simultaneous measurements over a 40 nm region anywhere from 200 to 900 nm. A microcomputer was used to control the array and a versatile computer program was developed to utilize this system for various spectrochemical measurements. The signal to dark current ratio of the array was compared with that of a photomultiplier (R-106) over the useful wavelength range and the former was found to be less than 1/100 of the latter in the region below 400 nm. However, when the array was not cooled, it could be used with integration time of up to 5 s for quantitative measurements and 20 s for qualitative measurements.

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