Abnormal X-ray Emission from Insulators Bombarded with Low Energy Ions

M. Song, K. Mitsuishi, M. Takeguchi, K. Furuya, R. C. Birtcher High Voltage Electron Microscopy Station, National Institute for Materials Science, Sakura 3-13, Tsukuba, 305-0003 Japan Materials Science Division, Argonne National Laboratory, MSD/212, 9700 South Cass Avenue, Argonne, IL 60439-4838 ABSTRACT An abnormal phenomenon, low energy ion induced X-ray emission from insulators is reported and discussed. Irradiation with He, Ga, Ar, and Xe ions in energy from 5 to 100 keV induces strong characteristic X-ray emission from insulator targets but not from conductive ones. The phenomenon is different from the high energy ion induced X-rays, such as PIXE (particle induced X-ray emission) in several aspects, such as very low energy of the used ions, existence of upper limit energy for the ion to induce X-rays. It is implied that the phenomenon relates not only to plus charging-up on surface of the irradiated specimen but may also to ion irradiation related process, such as sputtering. However, further study has to be done for a precise mechanism of the phenomenon. Features, such as high X-ray yields, suggest the phenomenon has potential applications in element analysis and studying ion-solid interaction.