[en] The spectrum of yttrium was reinvestigated from 2100 A to 3.5 μm. A total of 1658 lines in the spectra of neutral and singly ionized yttrium were measured. There are 247 classified lines in the spectrum of singly ionized yttrium and 937 classified lines in the spectrum of neutral yttrium. In the region from 1 to 3.5 μm 248 wavelengths were measured, this is a previously uninvestigated region of the spectrum where many strong lines were predicted from the known energy levels. Two types of sources were developed and used; hollow cathode light sources using a rare gas as a carrier gas and electrodeless discharge tubes containing yttrium iodide were constructed. With the aid of ab-initio calculations based on the Slater--Condon theory and the new wavelength measurements thirty new even levels and eighteen new odd levels of neutral yttrium were located. Twelve previously classified even levels and four previously classified odd levels have had their classification changed to be more consistent with the theoretical calculations. Ninety-seven even levels and eighty-two odd levels are listed with seven even levels and one odd level being unclassified.The accuracy of the level values for neutral yttrium was significantly improved based on the new wavelength measurements, as has also the accuracy of the level values of singly ionized yttrium. An automatic comparator was designed for the rapid and accurate wavelength measurements from spectrograms. The automatic comparator consists of a Grant Instruments Micro-densitometer--Comparator, Data General Nova 800 mini-computer, and associated peripherals. The entire process from data acquisition to wavelength determination is performed by the Nova with programs written in FORTRAN IV

[en] The Department of Energy's Programmatic Environmental Impact Statement (PEIS) required treatment system capacities for risk and cost calculation. Los Alamos was tasked with providing these capacities to the PEIS team. This involved understanding the Department of Energy (DOE) Complex waste, making the necessary changes to correct for problems, categorizing the waste for treatment, and determining the treatment system requirements. The treatment system requirements depended on the incoming waste, which varied for each PEIS case. The treatment system requirements also depended on the type of treatment that was desired. Because different groups contributing to the PEIS needed specific types of results, we provided the treatment system requirements in a variety of forms. In total, some 40 data files were created for the TRU cases, and for the MLLW case, there were 105 separate data files. Each data file represents one treatment case consisting of the selected waste from various sites, a selected treatment system, and the reporting requirements for such a case. The treatment system requirements in their most basic form are the treatment process rates for unit operations in the desired treatment system, based on a 10-year working life and 20-year accumulation of the waste. These results were reported in cubic meters and for the MLLW case, in kilograms as well. The treatment system model consisted of unit operations that are linked together. Each unit operation's function depended on the input waste streams, waste matrix, and contaminants. Each unit operation outputs one or more waste streams whose matrix, contaminants, and volume/mass may have changed as a result of the treatment. These output streams are then routed to the appropriate unit operation for additional treatment until the output waste stream meets the treatment requirements for disposal. The total waste for each unit operation was calculated as well as the waste for each matrix treated by the unit

[en] Calculation of energy levels from measured transitions is important in atomic spectroscopic research. We present an improved least squares program for such a calculation, a program that transfers easily to any modern computer using FORTRAN and that runs on minicomputers as well as large modern computers. We show in detail how to use this program

[en] High resolution Fourier transform spectrometry has been used to perform line width and line shape analysis of eighty-one iron I emision lines in the spectral range 290 to 390nm originating in the normal analytical zone of an inductively coupled plasma. Computer programs using non-linear least squares fitting techniques for line shape analysis were applied to the fully resolved spectra to determine Gaussian and Lorentzian components of the total observed line width. The effect of noise in the spectrum on the precision of the line fitting technique was assessed, and the importance of signal to noise ratio for line shape analysis is discussed. Translational (Doppler) temperatures were calculated from the Gaussian components of the line width and were found to be on the order of 6300⁰K. The excitation temperature of iron I was also determined from the same spectral data by the spectroscopic slope method based on the Einstein-Boltzmann expression for spectral intensity and was found to be on the order of 4700⁰K. 31 references

[en] Using an all-mirror optical system, an inductively coupled plasma is viewed top down and the light is directed to a dual grating, direct reading spectrograph. Top down viewing of the plasma, with masking of the image of the argon plasma torus at the spectrograph entrance slit, significantly reduces background signal from the source and permits the use of the depth of field of the optical system to achieve compromise conditions for viewing the plasma. Light from the plasma source is introduced to the optical system by means of a mirror situated directly over the plasma. The system is exhausted in such a way that cool air flowing past the mirror forms a thermal barrier between the mirror and the plasma. Elements such as copper and lead have atomic and ionic lines which tend to exhibit self absorption when viewed top down through the cooler ground state atoms in the plume of the plasma. One of the approaches to this problem is to shear off the plume of the plasma with a jet of air directed across the tip of the plasma. A second approach is to make use of the dual grating, direct reading spectrograph and real-time computer system which easily permits the setting of alternate lines for each element so that self absorption and matrix effects are minimized. The design of the dual-grating, direct-reading spectrograph allows for the mounting of more than 200 13-mm-dia photomultiplier tubes along the focal curves. In an effort to demonstrate the use of fiber optics as a viable technique for the closer placement of exit slits, a red sensitive photomultiplier tube was coupled with a 30-cm fiber-optic ribbon to detect light from the Li 670.784 nm line on the focal curve. It was successful and had the added advantages of absorbing second-order ultraviolet light

[en] The uranium emission spectrum from a hollow cathode discharge is displayed from 11,000 to 26,000 cm^-1. This atlas lists 4928 spectral lines of uranium; 3949 are classified to the neutral spectrum and 431 are classified to the singly ionized spectrum. Listed wavenumbers are accurate to +-0.003 cm^-1 and the listed relative intensities to +-8%. The richness of the spectrum makes this atlas useful for wavenumber calibration of lasers, spectrographs, and monochromators to an accuracy of 1 part in 10⁷. This atlas is also useful as a guide to the uranium spectrum, and relative oscillator strengths (gf values) can be calculated from the intensities to a precision of +-20%

[en] The region between 1 and 5.5 μm has been observed with a high-resolution Fourier transform spectrometer. See-through hollow cathode lamps with calcium fluoride windows were operated at high current. Special precautions were required to minimize interference by blackbody radiation from the hot cathode. Observed lines were measured to an absolute accuracy of about 0.001 cm^-1 and about 5% relative intensity accuracy. The argon carrier gas lines were readily distinguished by their much wider Doppler-broadened linewidths. Many lines were assigned to neutral or singly-ionized thorium on the basis of predicted transition wavenumbers calculated from accurate level lists. However, many lines remain to be assigned. This new spectral data connects to, and extends similar, spectral information given in our uranium and thorium atlases which cover the ultraviolet and visible regions

[en] Molten carbonate fuel cells (MCFCS) are being developed for large scale power generation. One source of fuel for MCFCs is coal gasifiers. This in turn presents the problem of coal gas contaminants and their effect on the MCFC. Of these contaminants (Pigeaud, June 1991), HCl is the contaminant that can have the greatest adverse effect. Those results indicate that HCI has the effect of first being adsorbed by the carbonate, second it converts to alkali chloride and particularly KCl, and third it volatilizes as KCl gas and is swept from the fuel cell. This has the effect of lowering the K+ content of the fuel cell, plugging the gas flow tubes, and effectively causing a shutdown of the fuel cell because of the changing eutectic mixture and a raising of the melting point. Because of this, our effort has been directed toward finding a suitable diagnostic for HCl. With this diagnostic we propose to investigate the physical parameters associated with HCl absorption and conversion to KCl. We also plan on taking this diagnostic to industry to test on a working MCFC to determine if the calculations for the HCl removal coupled with our measurements are verified in the test results

[en] The Analytical Chemistry Group of the Chemistry Division at Los Alamos National Laboratory has been investigating the analytical utility of the inductively coupled plasma (ICP) - Fourier transform spectrometer (FTS) combination. While a new state-of-the-art FTS facility is under construction at Los Alamos, preliminary data has been obtained on the one-meter FTS at the National Solar Observatory at Kitt Peak, Arizona. This paper presents an update of the Los Alamos FTS facility, which is expected to be completed in 1986, and presents data showing the analytical potential of an ICP-FTS system. Some of the potential problems of the multiplex disadvantage are discussed, and the advantages of the high resolution obtainable with the FTS are illustrated

[en] Wave-number measurements were made on 10 uranium and 2 thorium transitions using the optogalvanic effect in a hollow-cathode discharge to position a single-frequency, cw dye laser to the peak of a transition. The wave number of the dye laser was measured by comparing it with the wave number of an iodine-stabilized He-Ne laser. The accuracy of the wave-number measurements was +-0.0006 cm^-₁. The data agree within +-0.002 cm^-₁ with previously reported uranium and thorium measurements whose estimated accuracy was +-0.003 cm^-₁