On quantitative off-axis Scanning Transmission Ion Microscopy (STIM)

Spurred by a need to determine major (C, H, N and O) contents in biological tissue sections, a formalism for quantitative off-axis Scanning Transmission Ion Microscopy (OA-STIM) has been established. This can be used with, or without, simultaneous Elastic Backscattering Spectroscopy (EBS) to provide quantitative major element composition and thickness information. As part of the work, an empirical predictor with one free parameter for the proton-proton differential scattering cross section was implemented. The predictor values were in extremely close agreement with high accuracy literature data. For 2 MeV p(-12)C elastic scattering at forward angles <= 45 degrees an interpolation procedure was used to determine the relative deviations from the Rutherford cross sections were determined to be <= 6.4%. The interpolation was based on a Coulomb field, angular momentum quantum number and nuclear structure dependent nuclear penetration factor. Finally, the quantitative combination of simultaneous OA-STIM and EBS data is discussed.