Secondary Ion Mass, Energy, and Intensity Scales

Once the sample of interest is located within the analysis chamber and the desired vacuum level is attained, sample-specific prealignment procedures must be carried out on the respective SIMS instrument before data collection can proceed. As these tend to be analysis specific (dependent on the sample type and the information of interest), these should be carried out before each analysis, i.e. on a daily basis. These prealignment procedures must be carried out to ensure that  

The primary and secondary ion beams are well focused with all aberrations minimized according to the conditions used, i.e. the mass resolution, energy, and/or spatial resolntion required (aberrations are covered in Appendix A.6.2.1) 

The region of interest on the samples surface is within the instrument s ion optical field of view for both the primary and the secondary ion beams. This will also depend on the axes of both ion beams as these must intersect at the sample s surface. 

The analytical conditions must be optimized according to the sample type, the potential issues noted, the information required, and the instrument type used (Quadrupole, Time-of-Flight, or Magnetic Sector-based SIMS). This will include optimizing  

Such procedures assume that the secondary ion energy, mass, and intensity scales of the instrument are calibrated. Calibration procedures are discussed henceforth. 

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