Table 1 LA-MCICPMS instrument and operational parameters
From: U–Th isotopic microanalysis of zircon reference materials and KBSI working standards
MCICPMS | |
Instrument | Nu Plasma II |
RF power | 1300 W |
Reflected power | < 1 W |
Mixed gas and flow rate | Ar, ~ 0.9 L/min |
Auxiliary gas and flow rate | Ar, 0.8 L/min |
Cool gas and flow rate | Ar, 13 L/min |
Sampler cone | Ni (1 mm orifice) |
Skimmer cone | Ni (0.7 mm orifice) |
Data acquisition mode | Time resolved analysis |
Integration times | 0.4 s |
Collectors | 2 Faraday cups and 2 ion counters |
Measured isotopes | 238U, 232Th, 230Th, 228 mass |
Laser ablation system | |
Laser | ESI machines 193 nm ArF excimer laser |
Ablation mode | Single hole drilling |
Cell | Two volume 2 cell (10 × 10 cm) |
Sample transport tubing | 0.5 m length |
Pulse repetition rate and width | 10 Hz, < 4 ns |
Pulse energy density | ~ 6 J/cm2 |
Ablation duration | 30 s |
Carrier gas and flow rate | He, 0.3 L/min |
Crater size | 30 μm |
Drill depth | ~ 15 μm |