Title: On the Radioactive Dust from No.5 FUKURYU MARU
Abstract: Radioactive elements in radioactive substance collected on board No.5 Fukuryu Maru were analysed by usual method of chemical separation.The result of chemical separation and estimation of half-life as well as the absorption curve of β-ray confirmed or assumed the presence of nuclides;those were Sr89, Sr99, Y90, Zr95, Nb95m, Nb95, Ru103, Ru106, Rh106, Te132, I132, I131, Ba140, La140, Ce141, Ce144 and Pr144.Although Ca showed radioactivity, this was not conclusive.Also, the portion which was considered to belong to transuranium element showed the presence of α-ray by use of ionization chamber.Rare earth elements containing four of the above nuclides and other unidentified, nuclides occupied more than one-half of the radioactivity.