Johann-type laboratory-scale x-ray absorption spectrometer with versatile detection modes

Abstract

We present a low-cost laboratory X-ray absorption spectrometer that uses a conventional Xray tube source and bent Johann-type crystal monochromators. The instrument is designed for XAS studies in the 4-20 keV range which covers most K edges of 3d transition metals and L edges of 5d transition metals and actinides. The energy resolution is typically in the range of 1-5 eV at 10 keV depending on the crystal analyser and the Bragg angle. Measurements can be performed in transmission, fluorescence, and imaging modes. Due to its simple and modular design, the spectrometer can be modified to accommodate additional equipment and complex sample environments required for e.g. in situ studies. A showcase of various applications is presented.

The reduction of selenium(IV) by boreal Pseudomonas sp. strain T5-6-I – Effects on selenium(IV) uptake in Brassica oleracea

“…cells and in the differentially treated roots and leaves of B. oleracea plants was examined using X-ray absorption near-edge structure (XANES) spectroscopy. The XANES measurements were performed at Se K edge (12.7 keV) using a table top Johann-type spectrometer detailed in (Honkanen et al 2019). For the XANES experiments bacterial cultures were treated with 3 or 6 mM Se(IV) and incubated under aerobic conditions at 20 °C for 7 days.…”

“…The calculation of spectra from the raw instrument data and final visualizations were performed with custom Python scripts. The details of spectra calculation is presented in (Honkanen et al, 2019).…”

In‐situ X‐Ray Absorption Near Edge Structure Spectroscopy of a Solid Catalyst using a Laboratory‐Based Set‐up

“…Details about the laboratory-based X-ray absorption spectrometer can be found in the work of Honkanen et al [31] The in-situ XANES set-up is illustrated in Figure 1. The spectrometer uses the Bremstrahlung spectrum and is designed to work in the 4-20 keV photon energy range.…”

“…[15,16] Additional difficulties include the transport of the in-situ set-up and samples (e. g. air sensitive samples) to the synchrotron radiation facilities. [27][28][29][30][31][32] Interestingly, one can consider these developments as a revival of a somewhat older idea. [17][18][19][20][21][22][23][24][25][26] By using laboratorybased set-ups, different successful ex-situ XANES studies have been performed on diverse systems.…”

Sb-doped zirconium dioxide submicron fibers for separation of pertechnetate (TcO4–) from aqueous solutions

“…The redox state of Sb in the fibers was investigated with a self-assembled X-ray absorption spectroscopy (XAS) instrument. The instrument is built in a similar manner as the one designed and described by Honkanen et al [38] The samples were measured through a helium balloon to reduce X-ray attenuation by ambient air between the X-ray source (Mini-focused X-ray tube with Pd target, Micro X-ray), sample and a silicon drifted detector (Amptek XR-100SDD). A Si(400) crystal analyzer (ESRF) was used to select the energy range for the measurement.…”