Abstract: An apparatus is configured to receive x-rays propagating from an x-ray source. The apparatus includes first and second x-ray diffractors, the second x-ray diffractor downstream from the first x-ray diffractor and first and second x-ray detectors. The first x-ray diffractor is configured to receive the x-rays, to diffract a first spectral band of the x-rays to the first x-ray detector, and to transmit at least 2% of the received x-rays to the second x-ray diffractor. The second x-ray diffractor is configured to receive the transmitted x-rays from the first x-ray diffractor and to diffract a second spectral band of the x-rays to the second x-ray detector. The first x-ray detector is configured to measure a first spectrum of the first spectral band of the x-rays and the second x-ray detector is configured to measure a second spectrum of the second spectral band of the x-rays.

Abstract: An apparatus is configured to receive x-rays propagating from an x-ray source. The apparatus includes first and second x-ray diffractors, the second x-ray diffractor downstream from the first x-ray diffractor and first and second x-ray detectors. The first x-ray diffractor is configured to receive the x-rays, to diffract a first spectral band of the x-rays to the first x-ray detector, and to transmit at least 2% of the received x-rays to the second x-ray diffractor. The second x-ray diffractor is configured to receive the transmitted x-rays from the first x-ray diffractor and to diffract a second spectral band of the x-rays to the second x-ray detector. The first x-ray detector is configured to measure a first spectrum of the first spectral band of the x-rays and the second x-ray detector is configured to measure a second spectrum of the second spectral band of the x-rays.

Abstract: A fluorescence mode x-ray absorption spectroscopy apparatus includes an electron bombardment source of x-rays, a crystal analyzer, the source and the crystal analyzer defining a Rowland circle having a Rowland circle radius (R), a detector, and at least one stage configured to position a sample such that at least a portion of the sample is between the crystal analyzer and the detector.

Abstract: A fluorescence mode x-ray absorption spectroscopy apparatus includes an electron bombardment source of x-rays, a crystal analyzer, the source and the crystal analyzer defining a Rowland circle having a Rowland circle radius (R), a detector, and at least one stage configured to position a sample at a focal point of the Rowland circle with the detector facing the sample.

Abstract: An apparatus includes a crystal analyzer positioned relative to an x-ray source on a Rowland circle. The crystal analyzer includes crystal planes curved along at least one direction and configured to receive x-rays from the x-ray source and to disperse the received x-rays according to Bragg's law. The apparatus further includes a spatially resolving detector that includes a plurality of x-ray detection elements having a tunable first x-ray energy and/or a tunable second x-ray energy. The plurality of x-ray detection elements are configured to measure received dispersed x-rays having x-ray energies below the first x-ray energy while suppressing measurements above the first x-ray energy and/or to measure the received dispersed x-rays having x-ray energies above the second x-ray energy while suppressing measurements below the second x-ray energy.

Abstract: An apparatus includes a crystal analyzer positioned relative to an x-ray source on a Rowland circle in a tangential plane and having a Rowland circle radius (R). The crystal analyzer includes crystal planes curved along at least one direction within at least the tangential plane with a radius of curvature substantially equal to twice the Rowland circle radius (2R). The crystal planes are configured to receive x-rays from the x-ray source and to disperse the received x-rays according to Bragg's law. The apparatus further includes a spatially resolving detector configured to receive at least a portion of the dispersed x-rays. The spatially resolving detector includes a plurality of x-ray detection elements having a tunable first x-ray energy and/or a tunable second x-ray energy.