Time-resolved measurement of X-ray emission from Al2O3 targets induced by low-energy ion bombardment

Dependence of X-ray emission on ion current in low-energy ion-induced X-ray emission (LIIXE) was investigated for irradiation with 30-keV Ga+ ions. Time-resolved measurement of the X-ray emission from Al2O3 samples revealed that the X-ray emission fluctuated in intensity with time, but there was a tendency for the fluctuation to become smaller with increasing irradiation ion current. The fluctuation for irradiation with an ion current of 0.867 nA was much smaller than that for irradiation with an ion current of 0.087 nA. The main reason for the larger fluctuation for ion irradiation with smaller current was that high pulses of X-ray emission emerged irregularly with time. For the X-ray emission induced by irradiation with an ion current of 0.862 nA, a collection time of 50 s gave measured values with a deviation from the average of less than 13% for O K peak count, 28% for Al peak count, and 14% for the peak count ratio of Al K to 0 K. It is suggested that by choosing ion currents and collection time, X-ray peak counts can be measured with a deviation of about 10%, and that ratio of characteristic peak counts can be used to evaluate the relative content of elements in a sample. Copyright (C) 2006 John Wiley & Sons, Ltd.