2018 Volume 49 Pages 257-270
We have developed a portable X-ray powder diffractometer suitable for analysis of paintings. The diffractometer is composed of θ-θ type goniometer, light weight MAGPROTM X-ray tube and SDD. We can change X-ray tube from Cu to Cr, easily. 60 kV X-ray tube is suitable for XRF analysis utilizing white X-rays from high energy exciting source. Thus, we can obtain diffraction data and XRF data from the same sample point. We obtained a chance to analyze painting of Katsushika Hokusai (1760-1849) using this diffractometer and demonstrated the performance of the new diffractometer.
We brought a set of portable analytical instruments necessary for analysis of paintings to Hokusaikan in Obuse, Nagano: i.e. X-ray powder diffractometer, X-ray fluorescence spectrometer, Raman spectrometer, infrared camera, and conducted nondestructive onsite analysis of the paintings. The analyzed samples include the ceiling painting “Onami” and “Menami” (1845) drawn by Hokusai in his eighties and the pair of hanging scroll “Kiku-zu” (1840-1849). First, focusing on blue pigments, we succeeded in identifying multiple blue pigments, including Prussian blue. Analysis of the yellow pigment used in “Kiku-zu” revealed the use of As-S glass, an artificial new yellow pigment, just developed in Europe at that time, was identified and offering a new knowledge from the art historical point of view. Furthermore, we have revealed use of multiple red colors showing attractive coloration. It was proved scientifically that Hokusai was drawing vivid colors by using various colorants.
