9632360 Mao This award provides funding to the Carnegie Institution of Washington for the construction of a microdiffraction facility at the National Synchrotron Light Source (NSLS) of the Brookhaven National Laboratory. The facility will make use of the ultrabright X-ray beam from a superconducting wiggler insertion device at NSLS and provide for focus of the beam down to a 6-10 micron diameter at the position of samples subjected to ultrahigh static pressures of up to two to three hundred megabars in diamond anvil pressure devices. Laser heating of the microsamples will also allow heating of samples to several thousand degrees simultaneously with high pressure. The X-ray microdiffraction facility will be used primarily by Earth scientists at Carnegie and elsewhere investigating the properties of materials in the Earth's deep interior. ***