United States of America As Represented by the Administrator of Nasa

University System of Maryland

Keith Gendreau

Zaven Arzoumanian

Steven J Kenyon

Avilash Cramer

Wolfgang Krull

Richard Koenecke

Nick Salvatore Spartana

Jose Vanderlei Martins

Robert G Baker

Rajiv Gupta

Jake Hecla

Norman Dobson

The present invention relates to a novel, non-rotating tomographic imaging system, including a multi-source x-ray imaging module which includes multiple x-ray sources within a vacuum manifold, each equipped with a non-thermionic cathode which can reduce image scan time (and hence, motion artifacts), or delivered radiation dose, through under-sampled acquisition sequences, and without adding additional sources. The non-thermionic nature of the cathode enables rapid on/off switching of x-rays without concern as to the thermal mass or the thermal time-constant of the cathode. The modules can be flexibly interconnected to each other to allow configuration as part of a distributed ring of sources, or in other x-ray imaging geometries. Modularity provides the present invention an advantage in making it easier to debug and repair a distributed-source imaging system, such as a computed tomographic (CT) system.

Tomographic imaging system

A multiplexing x-ray fluorescence (MXRF) system and method are provided. The system can include a simple detector that counts x-rays with time resolution. A time-variable applied radiation source is used. The MXRF applied radiation source can produce an excitation spectrum with a peak average energy that grows with time and then recycles. Elemental identification can be achieved by time-correlating x-ray counts detected by the detector, with the time-variable applied radiation field. The system and method provide design flexibility for both commercial and NASA applications.

Multiplexing x-ray fluorescence system and method

A miniaturized high-speed modulated X-ray source (MXS) device and a method for rapidly and arbitrarily varying with time the output X-ray photon intensities and energies. The MXS device includes an ultraviolet emitter that emits ultraviolet light, a photocathode operably coupled to the ultraviolet light-emitting diode that emits electrons, an electron multiplier operably coupled to the photocathode that multiplies incident electrons, and an anode operably coupled to the electron multiplier that is configured to produce X-rays. The method for modulating MXS includes modulating an intensity of an ultraviolet emitter to emit ultraviolet light, generating electrons in response to the ultraviolet light, multiplying the electrons to become more electrons, and producing X-rays by an anode that includes a target material configured to produce X-rays in response to impact of the more electrons.

Miniaturized high-speed modulated X-ray source

An X-ray diffraction and X-ray fluorescence instrument for analyzing samples having no sample preparation includes a X-ray source configured to output a collimated X-ray beam comprising a continuum spectrum of X-rays to a predetermined coordinate and a photon-counting X-ray imaging spectrometer disposed to receive X-rays output from an unprepared sample disposed at the predetermined coordinate upon exposure of the unprepared sample to the collimated X-ray beam. The X-ray source and the photon-counting X-ray imaging spectrometer are arranged in a reflection geometry relative to the predetermined coordinate.

Instrument and method for X-ray diffraction, fluorescence, and crystal texture analysis without sample preparation

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Greenbelt, MD, United States of America

Keith Gendreau