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

摘要

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/mm~2. Among the several chemical states present in each element, the Ka line shifts corresponding to oxidation due to the irradiation were observed for CaHPO_3·H_2O (P~(3+)), and Na_2SO_3 (S~(4+)) samples. For Ca(H_2PO_2)_2 (P~(1+)) and Na_2S_2O_3 (S~(2-,6+) samples, spectral shapes of Ka 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.