The mobile micro-XRF scanner (MXRF) consists of a spectrometric head equipped with a low power microfocus X-ray tube (30W) with a Mo anode coupled to a focusing polycapillary optic. The spot of the beam coming out from the primary X-ray source is about 50 microns at 10 keV at a focus distance of 14.7 mm. The detection system is positioned in a 90-degree geometry with respect to the beam direction. It consists of 4 SDD detectors (with 50mm2 active area collimated to 40mm² for a total active area of 160 mm² and <130 eV energy resolution at 5.9 keV each) operated in parallel. This experimental set-up improves drastically the chemical sensitivity, and the detection limits of the device. A single scan with the XY axes travel system installed on the MXRF instrument can cover an area of 50x50cm2. The system operates with continuous scanning with a maximum speed up to 50mm/sec. A Z axis coupled to laser triangulation device is used for a dynamic correction spectrometric head position to maintain the source-sample distance uniform during the scanning. Due to the high intensity of the primary X-ray beam and the large solid angle covered by the multi-detectors system, measurements are usually made with a dwell-time per pixel in the range 15ms. Point analyses and/or a 2D elemental mapping (depending on the application) can be performed on the samples to better elucidate its elemental composition. The lateral resolution of the elemental images is in the range of 50-150 microns depending on the artworks dimensions. A 10x10cm2 surface mapped with a lateral resolution of 100 microns, at a scanning speed of 5 mm/s (15ms dwell time per pixel), takes approximately 4 hours. The system is equipped with a central unit (CU) for controlling the operational parameters of the scanner and to operate a dynamic analysis (full deconvolution of the pixel spectra on the fly) providing real-time elemental distribution images to users. The Macro-XRF scanner can be configured to perform scans in both vertical and horizontal geometries.

Image/RGB
Image/Gray scale
Dataset/2D
Dataset/Data package (images, spectra, other)
metadata (experimental conditions, comments relative to the point)

Noncontact (no physical contact)
Nondestructive (no permanent damage or alteration)
Noninvasive (no physical alteration)

up to 50x50cm2 (XY - Vertical scan)
up to 50x20cm2 (XZ - Horizontal scan)