RESOchron

The Logical combination for Geoscience Applications

In response to requirements of university and industry partners, ASI has developed a unique instrument with the capability to conduct U-Th-Pb-He triple-dating and trace element characterization of mineral chronometers. This instrument answers the needs of applications in basic geoscience research such as tectonics and landscape evolution studies, as well as for industry applications in petroleum basin analysis and mineral exploration.

Laser ablation helium thermochronology samples a precisely defi ned, defect-free volume of the crystal, with a known surface area, thereby overcoming two uncertainties in the traditional method of bulk crystal measurement. Double dates are obtained quickly and at low cost in a compact instrument based on RESOlution Laser Ablation (LA-ICPMS) and Alphachron™ technologies with well established heritage.

Resochron

 

Specifications

Helium Analysis System

  • High vacuum system consisting of dry backing pump, dry hybrid turbo pump with controller, and ion pump with controller
  • Quadropole mass spectrometer (QMS); range of mass magnitude: 1-100 amu; detector: Faraday Cup and SEM (Secondary Electron Multiplier; detection limit (SEM): 1e-14 hPa (7.5e-15 Torr); Ar Sensitivity (SEM): 200 A / hPa (265 A / Torr)
  • Stainless steel high-vacuum line with automatic and manual valves
  • Automated x-y laser stage with machine vision;
  • 970 nm diode laser, lens system, power supply and safety shield;
  • 25-sample capacity laser chamber with sapphire window;
  • 3 x 3.3 litre stainless steel tanks with 3He spike, an analytical 4He standard, and a 4He reference standard
  • Dedicated computer control system

Laser Ablation System

  • Excimer Laser with 193 nanometer wavelength
  • Dual volume, constant volume sample cell with minimum XY movement of 150mm x 100mm
  • Ultra-high vacuum cell that is compatible with the ablation sample cell
  • Pulse energy at the output window of the resonator of the laser @ 10Hz repetition rate > 10 mJ
  • Pulse to Pulse Energy stability < 2 RSD
  • Fluence @10Hz repletion rate: > 20 J/cm2
  • Repetition rate > 100 Hz
  • Minimum spot size range of 2-100um (squares and circles)
  • Long working distance imaging lens
  • Homogeneous energy distribution for flat bottomed ablation craters
  • Accuracy and repeatability of the XY positioning stage, better than 1 μm
  • Fast washout times (99% in < 1second)
  • Multiple mounting of standards and samples with any shape
  • Integrated, software controlled cell carrier gas delivery of Helium, and Nitrogen
  • Fully automated analysis capabilities
Applications