Beamline 12.2.2 Quick Facts
12.2.2 Quick facts
 Beamline 12.2.2 at the Advanced Light Source is a Synchrotron-based Hard X-ray Diffraction beamline specifically aimed at samples under high pressure within diamond anvil cells. The beamline photon energy range is 6-35keV with an x-ray spot size down to 10x10um. Resistive and laser heating of samples is available up to 3000K.    
Illustration of a slab of crust descending through the boundary between upper and lower mantle and then stalling at about 1000 km. This can be explained by an unexpected increase in the viscosity of lower-mantle material as measured recently on ALS Beamline 12.2.2. Some parts of the slab eventually continue their downward trajectory to the core–mantle boundary.
 "Slab stagnation in the shallow lower mantle linked to an increase in mantle viscosity," Nat. Geosci. 8, 311 (2015). Hauke Marquardt and Lowell Miyagi
Radial X-ray diffraction indicates that ferropericlase becomes 100 times more viscous at pressures corresponding to the depth at which the slabs stall..  See ALS Highlights for extended description

 Financial  Support
U.S. Department of Energy - The Advanced Light Source is supported by the Director, Office of Science, Office of Basic Energy Sciences, of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231.
COMPRES - the Consortium for Materials Properties Research in Earth Sciences under NSF Cooperative Agreement EAR 10-43050. 

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