DETECTOR DISCRIMINATION IN SIMS .2. ION-TO-ELECTRON CONVERTER YIELD FACTORS FOR NEGATIVE-IONS

Ion-to-electron converter relative secondary electron yield factors for an impact energy of 4.5 keV have been determined for atomic, monoxide, dioxide, and trioxide negative ions representing 35 elements using a CAMECA IMS-300 Ion Microanalyzer with a CuBe converter dynode. The yield at the detector generally increases as the number of atoms in the ion increases; the mass dependence of the detector yield factors for each ion type follows an m-1/2 mass dependence, suggesting kinetic emission is the primary electron source. Least-squares fit parameters for the m-1/2 curve for each ion type are tabulated. Scaling factors to change the tabulated raw data into γabs values for the negative ions reported here and for the positive ions reported in a previous paper are deduced. The data can be used to convert instrumental signals into true relative ion currents for quantitative analysis. © 1979.