Abstract:
An instrument for the chemical analysis of coal and other hydrocarbons combines TGA and FT-IR principles, and utilizes helium to carry the volatiles evolved by pyrolysis of the sample into the optical cell of the FT-IR spectrometer. The connection between the TGA furnace and the optical cell is substantially direct and non-impeding to fluid flow, and the carrier gas is preheated to the same temperature as the sample, preferably using a common heating element.
Abstract:
A fast and practical method for the analysis of patterned samples of semiconductor integrated circuits, and other materials, determines the thickness and composition of layers fabricated during manufacture. The method employs a measurement spot that is sufficiently large to irradiate areas of two or more different regions of the sample that result from its patterned features, generally at replicable locations. In carrying out the method, one or more of reflectance, transmittance, and radiance spectrance is measured, and the various parameters characterizing the thickness and composition in the patterned areas are obtained using, for example, a model-based analysis of the polarization and amplitude of the emanating radiation, the model parameters being iteratively adjusted to achieve a match with measured values. The method can be made fast and practical by using measurements that are taken both before and also after treatment steps are effected, and/or by using measurements from the same location on designated samples undergoing the same process, to reduce the number of unknown parameters in a reference model.
Abstract:
The structure of the invention serves to support mirrors defining a reflective channel, which can dynamically be reciprocally widened and narrowed, as in a two-beam interferometer. It is effectively divided, by pivot points on an intermedial axis, into two opposite portions of equal mass, thus affording to the structure immunization against translational forces transmitted through those points. The opposite portions also have their centers of gravity remotely located, so as to generate a counteracting torque in response to moments of rotational inertia transmitted through the pivot points. In the structure, integrally formed planar pieces are assembled to provide contiguous elongate elements and an interposed connecting web element, a plurality of which web elements produce a flexure joint.
Abstract:
The structure serves to support any of various elements and objects, normally for translational movement. It is effectively divided, by pivot points on an intermedial axis, into two opposite portions of equal mass, thus affording to the structure immunization against translational forces transmitted through those points. The opposite portions also have their centers of gravity remotely located, so as to generate a counteracting torque in response to moments of rotational inertia transmitted through the pivot points. Integrally formed planar pieces are assembled to provide contiguous elongate elements and an interposed connecting web element, a plurality of which web elements produce a flexure joint in the structure.
Abstract:
A multiplicity of one-piece flexure plates are assembled in pairs to provide a support system on which a retroreflector may be mounted for reciprocal motion. Combined with balance bodies, the flexure plates provide a support system having portions that are dynamically and statically balanced with one another, irrespective of orientation, so as to thereby immunize the unit against extraneous forces. The motion transfer assembly is especially adapted for use to support a moving retroreflector in a two-arm interferometer that may further include a beamsplitter assembly constructed from a one-piece, integrally formed body, the body having convergent, optically flat planar surfaces of specular reflectance, and means for adjustably mounting a beamsplitter therein. The spectrometer is of modular construction, and employs an integrated clocking sub-assembly as well as a light-weight voice-coil motor.
Abstract:
The apparatus and method permit simultaneous and precise determination of the temperature and spectral emittance, over a wide spectral region, of a hot sample. Radiance, and hemispherical reflectance and transmittance measurements are employed, and FT-IR technology is advantageously applied. Reflectance and (where necessary) transmittance measurements are utilized to determine the fraction of incident radiation, of selected wavelength, that is absorbed by the sample, in turn establishing a spectral emittance value. Taken with the measured radiance at the same wavelength, the spectral emittance value will provide a quantity that can be matched with the spectral radiance of a theoretical black body, again at the selected wavelength, to thereby derive the temperature of the hot sample; this in turn enables determination of the spectral emittance of the sample over a desired spectral range.
Abstract:
An optical technique for determining surface temperature utilizes the Christiansen effect that is exhibited by dielectric materials; i.e., strong absorption bands at certain wavenumber values, causing the radiance of the material to be that which would characterize a theoretical black body at that wavenumber value.
Abstract:
The method determines the thickness and the free carrier concentration of at least one layer of a structure. An exposed surface of the structure is irradiated using spectral radiation, and the measured reflectance spectrum is compared to a calculated spectrum. Using algorithms that include terms representative of complex refractive indices, layer thickness, dielectric constants, and free carrier concentrations, values are iteratively assigned to the thickness and free carrier concentration parameters so as to produce a best fit relationship between the compared spectra, and to thereby determine those parameters.
Abstract:
The structure of the invention serves to support mirrors defining a reflective channel, which can dynamically be reciprocally widened and narrowed, as in a two-beam interferometer. It is effectively divided, by pivot points on an intermedial axis, into two opposite portions of equal mass, thus affording to the structure immunization against translational forces transmitted through those points. The opposite portions also have their centers of gravity remotely located, so as to generate a counteracting torque in response to moments of rotational inertia transmitted through the pivot points. In the structure, integrally formed planar pieces are assembled to provide contiguous elongate elements and an interposed connecting web element, a plurality of which web elements produce a flexure joint.
Abstract:
An aerodynamically cleaned heat-exchanger is used in heating apparatus in which the radiant energy of a dirty fuel, such as coal or char, is efficiently recovered while the exposed heat-exchange components are protected from the deleterious combustion products.