Portable X-ray fluorescence spectrometer system containing a low-level radioisotope and its application to the non-destructive analysis of inorganic colorants used for the traditional Japanese votive picture

Abstract

A portable RI X-ray fluorescence spectrometer having a weight of 1800 g was constructed by using a radiation annular source (241 Am sealed up with ceramics, 1.85 MBq), a small Si-PIN photodiode X-ray detector mounted on a Peltier cooling device, an amplifier and a pocket-type multi -channel pulse-height analyzer. It could also be applied to a non-destructive analysis of the blue colorant in the original Japanese votive picture "Rashoumon-zu", offered to shrine in 1682. Consequently, it was clarified that the blue colorant (X) was "Smalt" containing Ca, Fe, Co, Ni and As as major elements.