Resolve the discrepancy between alternative strontium bridge isotopes

Resolve the approximately 3% discrepancy between the Sr dose factors obtained using 86Sr and 88Sr as alternative bridge isotopes for linking the 9 ns and 20 ns phases in multiphase ToF-SIMS acquisition.

Background

The multiphase reconstruction links the abundant 88Sr signal measured at 9 ns with weaker strontium isotopes measured at 20 ns by using an isotope that remains linear in both phases. The primary analysis uses 86Sr as the bridge, while 88Sr at 20 ns provides an internal alternative because it remains below approximately three corrected counts per pulse.

The two bridge choices yield dose factors differing by about 3%, and consequently produce slightly different reconstructed Sr ratios. The paper reports the discrepancy but does not establish whether it arises from residual saturation, spectral interference, pulse-width-dependent response, or another instrumental effect.