ITRAX: description and evaluation of a new multi-function X-ray core scanner

TLDR

Traditional XRF analysis of sediment elements is time‑consuming and requires gram‑scale samples that are often scarce. The paper describes the construction, characteristics, and recent technical developments of the ITRAX core scanner. ITRAX uses a focused micro‑X‑ray beam through a flat capillary waveguide, scanning split cores incrementally with a programmable motor to obtain X‑radiography and XRF data. ITRAX non‑destructively captures optical, radiographic, and high‑resolution elemental data from sediment cores up to 1.8 m at 200 µm resolution, outperforming traditional lower‑resolution XRF and guiding further sampling.

Abstract

Abstract A new automated multi-function core scanning instrument, named ITRAX, has been developed that records optical, radiographic and elemental variations from sediment half cores up to 1.8 m long at a resolution as fine as 200 μm. An intense micro-X-ray beam focused through a flat capillary waveguide is used to irradiate samples to enable both X-radiography and X-ray fluorescence (XRF) analysis. Data are acquired incrementally by advancing a split core, via a programmable stepped motor drive, through the flat, rectangular-section X-ray beam. Traditional XRF determination of element composition in sediments provides high-quality data, but it takes a considerable time and normally consumes gram quantities of material that is often only available in limited quantities. The ITRAX core scanner non-destructively collects optical and X-radiographic images, and provides high-resolution elemental profiles that are invaluable for guiding sample selection for further (destructive) detailed sampling. This paper presents a description of the construction, characteristics and capabilities of the ITRAX system. High-resolution ITRAX data obtained from sediment cores are also presented and compared with results from traditional wavelength-dispersive XRF analysis at lower resolution. Finally, some recent technical developments linked to the second-generation ITRAX are presented.