Martin Marietta Corporation

Other

Benton C Clark, Iii

Michael G Thornton

William H Tobey

R Wayne Stafford

Todd E Crumbaker

A portable x-ray fluorescence spectrometer has a portable sensor unit containing a battery, a high voltage power supply, an x-ray tube which produces a beam x-ray radiation directed toward a target sample, and a detector for fluorescent x-rays produced by the sample. If a silicon-lithium detector is used, the sensor unit also contains either a thermoelectric or thermochemical cooler, or a small dewar flask containing liquid nitrogen to cool the detector. A pulse height analyzer ('PHA') generates a spectrum of data for each sample consisting of the number of fluorescent x-rays detected as a function of their energy level. The PHA can also store spectrum data for a number of samples in the field. A processing unit can be attached to the pulse height analyzer to upload and analyze the stored spectrum data for each sample. The processing unit provides a graphic display of the spectrum data for each sample, and provides qualitative and/or quantitative analysis of the elemental composition of the sample by comparing the peaks in the sample spectrum against known x-ray energies for various chemical elements. An optional filtration enclosure can be used to filter particles from a sample suspension, either in the form of a natural suspension or a chemically created precipitate. The sensor unit is then temporarily attached to the filtration unit to analyze the particles collected by the filter medium.

Portable x-ray fluorescence spectrometer for environmental monitoring of

A projection system derived from certain solid geometrical properties using two aperture plates bearing arrays of holes with well defined spacing projects radiation from diverse sources such as electromagnetic radiation, visible and invisible light radiation, discrete particles, X-rays, gamma rays, charged and uncharged particles, as a multi-dot radiation image pattern onto a distant target, overcoming the enormous intensity losses inherent in prior art for pin hole projection of test patterns. The source angular emission function may be of nearly any type, from omni-directional (perfectly diffuse) to uni-directional. Such dot patterns are suitable for evaluating imaging systems as well as the critical operating parameters of mapping spectrometer sensors. The lensless projection system is capable of superimposing radiation source rays from every hole in the first aperture plate onto each image dot at the focal plane with dramatic increase in intensity of the projected image.

High brilliance lensless projection system of test patterns

A liquid sample holder having a fluid sample receptacle bounded by two substantially parallel sheets. The parallel sheets define a fluid analysis area, and adjacent to that area is a peripheral overflow. Air bubbles are trapped in the peripheral overflow because the distance between the plates is smaller than the depth or thickness of the peripheral overflow.

Liquid sample holder

A semi-automatic quantitative filtration assembly is disclosed having a measuring means to measure and present a known quantity of fluid for filtering and a fluid holding means adjacent to a filter medium. The fluid holding means is adapted to receive and hold excess fluid during filtering and to prevent intermixing with a known quantity of fluid to be presented to filtering. The filtering apparatus is designed to filter a quantitative amount of fluid and receive fluid in the fluid holding tank which is excess sample fluid or fluid unwanted as a result of error or operational failure and which drains to a common vacuum/waste means for filtered fluid. A variety of features are also provided to insure proper operation and minimize operator error.

Self-metering semi-automatic quantitative filtration assembly

A field portable X-ray fluorescent spectrometer is described including a multichannel analyzer (2) and a plurality of interchangeable sensor heads (4). Each sensor head includes a shutter (100) which, when open, permits one of several radiation sources (80, 82) to irradiate a material to be analyzed. The returned radiation is detected by a corresponding detector (86, 90), which provides corresponding data in response. This shutter has calibration plaques attached to it so that, when closed, the plaques are exposed to the radiation sources and return radiation having selected energy distributions to the detectors. The multichannel analyzer uses the resulting detector data to calibrate the sensor head. Each sensor head includes circuitry (290) for identifying itself to the multichannel analyzer. The analyzer automatically adapts its operation in accordance with this identification. When the shutter is open, the multichannel analyzer utilizes the detector data to accumulate an energy spectrum of the material being analyzed, and displays the spectrum on a display screen (12). A cursor control (28) allows the operator to move a cursor along the displayed spectrum. A display (32) is automatically provided with a display of the symbol of the element, if any, having its major spectral peak at the position identified by the cursor. Secondary indications identify other positions along the spectrum at which peaks would appear if the element were present. Memory (202) is provided for storing a number of reference spectra, any of one of which may be displayed on the screen along with the acquired spectrum for comparison purposes. The memory (202) also stores previously acquired spectra for later analysis. The analyzer also includes other operational features, such as normalization, window control, and ratio and concentration determination, to permit the operator to quantitatively analyze materials in the field.

Field portable element analysis unit

A proximity sensor utilizing nucleonic radiation fluorescence to detect the presence, position and/or distance of a target object from a monitoring object. The inventive system has particular application in collision avoidance systems for subsatellites, final docking alignment systems in spacecraft applications, collision avoidance systems for teleoperated manipulative arms, homing devices for manipulative devices as well as hazard detection systems for planatary rovers. Where necessary, the target object is fitted with cooperative radiation fluorescent material. The monitoring object looks for and detects the preselected fluorescence, thus discriminating between radiation emitted by the target object and extraneous radiation.

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Littleton, CO, United States of America

Benton C Clark, Iii