Metal oxides laser emission from

CIR-FTIR spectroscopy provides a direct technique for studying in situ hydrous metal oxide surfaces and molecules adsorbed on these surfaces (37). By itself, FTIR spectrometry is a well established technique which offers numerous advantages over dispersive (grating) IR spectrometry (1) improved accuracy in frequency measurements through the use of a HeNe laser (2) simultaneous frequency viewing (3) rapid, repetitive scanning which allows many spectra to be collected in a small time interval (4) miriimal thermal effects from IR beam and (5) no detection of sample IR emissions (38). 

Fk . 17. Initial decay of the photoluminescence of Ru(bpy) ]" complexes adsorbed on various powder metal oxides at 295 K. (a) Picosecond laser excitation at 540 imi and the emission monitored at 540 nm. (b) Nanosecond laser excitation at 450 nm and the emission monitored at 580 nm [reproduced with permission from Hashimoto et at... 

For optical pyrometry, the well would serve as a blackbody hole 1 cm (0,39 in.) in diameter by 5 cm (1.97 in.) deep, the bottom of which would be in close thermal contact with the coolant stream. The minimum wall thickness at the bottom of the blackbody hole would have been set by pressure containment considerations The exterior surfaces of the well would be refractory metal with a very low vapor pressure that does not form stable oxide layers, such as Mo, Re, or W, The surface could be textured or grovm via chemical vapor deposition for increased emissivity. However, a simple polished metal surface likely would suffice. Some recalibration schemes, which require one to reflect a laser pulse off the measurement surface, would prefer a lower emissivity and likely would not benefit from a blackbody hole. 

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