description: primary impact energy 20 keV
gold coat (50+)200 × 3 °A
secondary accelerating voltage −10 kV
primary beam current 200 pA (4H × 3V μm)
primary beam raster 5 × 5 μm (7 × 7 μm for first 140 s)
entrance slit width 80 μm
field aperture dimension 800 × 800 μm (20 × 20 μm on sample)
energy band pass from −10 to +30 (40 eV width)
exit slit width 200 μm for 17O− and 400 μm for 16O− and 18O−
mass resolution (m/m) 8,000 for 17O− and 2,400 for 16O− and 18O−
detectors FC (L’2), EM (axial), and EM (H1) for 16O−, 17O−, and 18O−
peam optimization automatic FA centering at beginning (30 s)
mass calibration automatic mass centering at beginning (15 s)
pre-sputter duration 3 min 10 s including beam optimization and mass calibration
secondary ion integration 14.5 s × 40 cycles
contribution of 16OH− to 17O− less than 0.1h
background estimation every 1 hour