A Rapid Screening Method of Target Particles for Tof-Sims Analysis

In the nuclear contaminated sample collected from the environment, only a few radioactive particles with a diameter of several μm are present among the numerous particles on a substrate. It takes a lot of time to find these radioactive particles using TOF-SIMS analysis method. Furthermore, it is concern that the rare radioactive particles will be worn with the sputtering by the focused ion beam. We developed a screening method that can quickly lock the position of radioactive particles within a small range. Here, the screening method was practiced using an actual sample. As a result, the position of the radioactive particles was narrowed down to the range of 500 μm. TOF-SIMS analysis was performed within the area range. As a result, it was presumed that radioactive Cs was likely not to be present on the outermost surface of the sample. Hence it is difficult to screen radioactive particles using only TOF-SIMS. But the usefulness of the screening method was confirmed.