Parameters
Mass spectrometer
  Cool gas (liter min−1 Ar)13.0
  Auxiliary gas (liter min−1 Ar)0.80
  Sample/make-up gas (liter min−1 Ar)1.06
  Power (W)1200
Data acquisition
  Masses202Hg, 204Pb, 206Pb, 207Pb,
208Pb, 232Th, 235U, 238U
  Detection modeIon counting and analog
  ScanningEscan
  Sample time per peak (s)0.0052, 0.0078, 0.0202, 0.0284,
0.0026, 0.0026, 0.0154, 0.0104
  Number of sample per peak4
  Runs/sweeps per analysis73
  Blank at beginning of each6
  Washout and blank at the end of each (s)11
  Acquisition modeSample blocks
  Acquisition initiationExternal trigger from laser scan
  LaserTeledyne Photon Machines G2
  Type and wavelengthExcimer 193 nm
  Sample cellHelex-fast
  Analyte tubingTeflon
  Laser energy (mJ)7.0 constant energy
  Laser fluence (J cm−2)10.16
  Rep rate (Hz)7
  Preablation pass3 bursts at 20 μm
  Analysis pass110 bursts at 12 μm
  Drill rate (μm/burst)~0.053 (52)
  MFC1, MFC2 (liter min−1 He)0.110, 0.290