Compact focusing von Hamos spectrometer for quantitative x-ray spectroscopy

Abstract

A compact focusing crystal spectrometer based on the von Hamos scheme is described. Cylindrically curved mica and graphite crystals with a radius of curvature of Rϭ20 mm are used in the spectrometer. A front illuminated charge-coupled device ͑CCD͒ linear array detector makes this spectrometer useful for real-time spectroscopy of laser-produced plasma x-ray sources within the wavelength range of ϭ1.8-10 Å. Calibration of crystals and the CCD linear array makes it possible to measure absolute photon fluxes. X-ray spectra in an absolute intensity scale were obtained from Mg, Ti, and Fe laser-produced plasmas, with a spectral resolution /␦ ϭ800-2000 for the mica and /␦ϭ200-300 for graphite crystal spectrometers. The spectrometer has high efficiency in a wide spectral range, it is compact ͑40 mm diam, 150 mm length͒, easy to align, and flexible. The spectrometer is promising for absolute spectral measurements of x-ray radiation of low-intensity sources ͑femtosecond laser-produced plasmas, micropinches, electron-beam-ion-trap sources, etc.͒.

A laboratory-based hard x-ray monochromator for high-resolution x-ray emission spectroscopy and x-ray absorption near edge structure measurements

“…This has been especially true after the development and commercial availability of CCD-based x-ray detectors allowed the highly productive implementation of von Hamos style, wavelength dispersive spectrometers. [65][66][67][68][69][70] Laboratory-based work using SBCA's is less common, but includes comparative studies of x-ray emission from direct x-ray excitation as opposed to from Kcapture. 83,88 …”

“…By contrast, and with only rare exceptions in the last 20 years, 'routine' hard x-ray XAFS [49][50][51][52][53][54][55][56][57][58][59][60][61][62][63][64] and high-resolution XES [65][66][67][68][69][70] can only be performed at the synchrotron light sources.…”

A von Hamos x-ray spectrometer based on a segmented-type diffraction crystal for single-shot x-ray emission spectroscopy and time-resolved resonant inelastic x-ray scattering studies

“…The spectrometer geometry allows recording a wide energy range x-ray emission spectrum at a single excitation energy and has found a variety of applications in combination with lab, synchrotron, and XFEL sources. 30,[40][41][42][43][44] Thanks to the dispersive-type of diffraction, the spectrometer geometry provides the possibility of a single-shot measurement with a total energy bandwidth ranging from a few tens to a few hundreds of eV. The development of innovative and compact von Hamos spectrometers has also benefited from the parallel advances of position-sensitive detectors.…”

Formation of quasi-monochromatic soft x-ray radiation from laser-produced plasmas

“…The contrast ratio was equal to [5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20]. These values are the low limit ofthe measuring values when the experimental errors are defined by the unreproducibility of laser pulse energy from shot to shot.…”