Macro-XRF scanning produces elemental distribution images, i.e. greyscale maps for each chemical element present in the entire object analysed. These maps can be combined to form RGB composite images which highlight the presence of two or more chemical elements in the same area, facilitating the identification of certain pigments. You can view elemental maps of the four illuminated initials from the Florentine choir books painted c. 1370 - c. 1450 (Marlay cuttings It. 13A, It. 13.i, It. 13.ii and MS 5-1979) by selecting the corresponding 'Layer' in the individual folio page.
MA-XRF scanning was carried out on some manuscript leaves by Stijn Legrand and Koen Janssens (AXES Research Group, Dept of Chemistry, University of Antwerp), by means of a dedicated instrument, developed at the University of Antwerp. The instrument is equipped with a Magnum X-ray tube (Moxtek) with a Rh anode, operated at 45 kV and 200 μA. Two Vortex EX-90 detectors (Hitachi, each with a 50 mm2 active area) are mounted under an angle of 20° relative to the primary beam to detect the X-ray radiation under a large solid angle. The manuscript leaves were positioned about 1.5 cm away from the scanning head, parallel to the scanner’s plane of movement. Scanning times ranged between 9 and 24 hours for each object.
Several other manuscript leaves were by Paolo Romano (IBAM-CNR) and Claudia Caliri (LNS-INFN) with a MA-XRF scanner developed at the LANDIS laboratory (LNS-INFN and IBAM-CNR, Catania). The instrument consists of a microfocus Rh-target X-ray tube equipped with a polycapillary optic and a large active area SDD detector with high energy resolution. The MA-XRF scan covers an area of up to 105x70 with maximum spatial resolution of 35 micron. Scanning times ranged between 1 and 3 hours per object.
