Laser heated diamond cell system at the Advanced Photon Source for in situx-ray measurements at high pressure and temperature

We describe a laser heated diamond anvil cell system at the GeoSoilEnviroCA RS sector at the Advanced Photon Source. The system can be used for in situ x-ray measurements at simultaneously ultrahigh pressures (to > 150 GPa) an d ultrahigh temperatures (to > 4000 K). Design goals of the laser heating s ystem include generation of a large heating volume compared to the x-ray be am size, minimization of the sample temperature gradients both radially and axially in the diamond anvil cell, and maximization of heating stability. The system is based on double-sided laser heating technique and consists of two Nd:YLF lasers with one operating in TEM00 mode and the other in TEM01* mode, optics to heat the sample from both sides, and two spectroradiometri c systems for temperature measurements on both sides. When combined with an x-ray microbeam (3-10 mum) technique, a temperature variation of less than 50 K can be achieved within an x-ray sampled region for longer than 10 min . The system has been used to obtain in situ structural data and high tempe rature equations of state on metals, oxides, and silicates to 3500 K and 16 0 GPa. (C) 2001 American Institute of Physics.