X-Ray Fluorescence (XRF) Core Scanners

Overview

---

Instrument Make and Model

AvaaTech, 3rd Generation Core Scanner
AvaaTech, 4th Generation Core Scanner

---

Estimated Measurement Time

• Sample Preparation: 20-60 minutes
• Measurement Time (h:mm) to scan a 1.5 m section:

---

Principles & Analytical Capabilities

X-rays excite the surface of a sample to fluorescence secondary x-rays that are detected by the silicon drift detectors (SDD). These systems utilize energy dispersive spectroscopy (EDS) to measure the characteristic x-rays. They are built to measure user defined scanning objectives, where elements of interest can be retrieved through in-house models on a defined resolution scale set by the user. Data from XRF scanners at the GCR is semi-quantitative. If quantitative measurements are needed please contact the GCR for more information.

Both XRF scanners equipped with 100W rhodium side-window x-ray tubes, complemented with the Brightspec SDD’s. Both instruments come with four machined core holders with a maximum of ~12 cm and minimum of 4 cm core width accommodation.

At the GCR, premade models are created for ease, at the 10, 30, and 50kV energy conditions. Additional energy conditions are available and refined to incorporate higher resolution scans (<1cm window slit size). At these energy conditions, the 10kV, with no filter, covers geologically relevant major and minor elements from Al to Fe, possibly Mg if it exists abundantly in certain samples (i.e. igneous hard rocks). The 30kV incorporates heavier major and minor elements (Ca to Fe), with additional trace elements such as Ni, Sr, Rb, Zr, and more. The 50kV is generally used for Ba, the heaviest element that can be reliably measured using our XRF’s. These conditions retrieve the K-line configuration of elements in samples, which is more readily available than L- or M-lines. Though L-lines may be useful for much heavier elements (>Ba) but are more susceptible to spectral line overlap, making interpretation difficult and unreliable in most cases.

---

Data Generated

Data components:

• K-alpha values of each element based on the specific element's electron binding energy (counts)

Data files:

• Results (CSV): tabular file of processed XRF spectral data. One file is generated for each energy condition (kV).

Raw files:

• Spectral File (SPE): raw data with associated metadata for instrument parameters, including offset, voltage, current, and filter.
• Instrument File (AXML): bAxil software batch instrument settings and model file for processing spectra.

---

Data Example

---

Procedures & Manuals

---

References

¹Ronge, T.A., Kutterolf, S., Fernandez-Perez, T.I., Manga, M., Metcalfe, A., Preine, J., Tominaga, M., Woodhouse, A., Yeon, J., Druitt, T., Beethe, S., Bernard, A., Berthod, C., Chen, H., Chiyonobu, S., Clark, A., DeBari, S., Gertisser, R., Hübscher, C., Johnston, R.M., Jones, C., Joshi, K.B., Kletetschka, G., Koukousioura, O., Li, X., McCanta, M., McIntosh, I., Morris, A., Nomikou, P., Pank, K., Peccia, A., Polymenakou, P.N., and Yamamoto, Y., 2024. Data report: X-ray fluorescence scanning of Sites U1591 and U1599, IODP Expedition 398, Hellenic Arc Volcanic Field. In Druitt, T.H., Kutterolf, S., Ronge, T.A., and the Expedition 398 Scientists, Hellenic Arc Volcanic Field. Proceedings of the International Ocean Discovery Program, 398: College Station, TX (International Ocean Discovery Program). https://doi.org/10.14379/iodp.proc.398.204.2024