Target Temperature Rise and Gas Emission during Chemical State Analysis by WD-PIXE Measurement

Abstract

Preliminary measurements on target temperature rise and gas emission were conducted during a 2‐MeV proton irradiation to investigate the mechanism of the chemical state changes of phosphorus, sulfur, and chlorine during high‐resolution WD‐PIXE measurements. Sulfur and phosphorus targets were irradiated for approximately 1 hour using proton beams with a current density of 7.5 nA/mm2. Among the several chemical states present in each element, the Kα line shifts corresponding to oxidation due to the irradiation were observed for CaHPO3⋅H2O (P3+), and Na2SO3 (S4+) samples. For Ca(H2PO2)2 (P1+) and Na2S2O3 (S2−,6+) samples, spectral shapes of Kα X‐ray changed during the irradiation. From the measured results on the temperature and gases, it was found that these chemical state changes accompanied emission of gaseous thermal decomposition products. During the change, sample temperature was measured to be as high as 200–400° C.