A novel von Hamos spectrometer for efficient X-ray emission spectroscopy in the laboratory

Abstract

We present a novel, highly efficient von Hamos spectrometer for X-ray emission spectroscopy (XES) in the laboratory using highly annealed pyrolitic graphite crystals as the dispersive element. The spectrometer covers an energy range from 2.5 keV to 15 keV giving access to chemical speciation and information about the electronic configuration of 3d transition metals by means of the Kβ multiplet. XES spectra of Ti compounds are presented to demonstrate the speciation capabilities of the instrument. A spectral resolving power of E/ΔE = 2000 at 8 keV was achieved. Typical acquisition times range from 10 min for bulk material to hours for thin samples below 1 μm.

Benchmark results and theoretical treatments for valence-to-core x-ray emission spectroscopy in transition metal compounds

“…[59] Here we employed a Rowland-circle spectrometer developed at the University of Washington. [64][65][66] This low-powered prototype instrument achieves synchrotron-quality energy resolution and also count rates comparable to what would be obtained for the same XES studies at monochromatized bending magnet beamlines at third-generation synchrotrons.…”

“…This has led to continuing effort by several groups to develop laboratory-based XES capabilities. [59][60][61][62][63] Here, using this equipment at the University of Washington, [64][65][66] we present a high-quality VTC dataset of several inorganic Zn and Fe compounds. These compounds provide an interesting range of local electronic and atomic structure while retaining sufficient structural simplicity such that theoretical treatment should not, a priori, be challenged by material complexity.…”

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 compact and versatile tender X-ray single-shot spectrometer for online XFEL diagnostics

“…The solution and the concept for the Tender X-ray Single-Shot Spectrometer (TXS) was found in the current devices based on curved crystals in Johann (1931), Johansson (1933) or in von Hamos (1933,1934) geometries, which are designed to deliver information as spectrometers for resonant inelastic X-ray scattering (RIXS), X-ray emission spectroscopy (XES) or X-ray Raman scattering (XRS) studies at X-ray free-electron lasers, laboratories (Alonso-Mori et al, 2012;Anklamm et al, 2014), synchrotrons in the hard (Hayashi et al, 2004) and tender X-ray ranges (Hoszowska & Dousse, 2004) and ion sources (Kavčič et al, 2009(Kavčič et al, , 2012. Our spectrometer concept is based on a dispersive von Hamos geometry and capable of measuring X-ray emissions over the entire photon energy range of interest.…”