A rotating autoclave for centrifuge studies: Falling sphere viscometry

The design and construction of a rotating autoclave are presented for in situ studies of silicate melts and partially molten samples at elevated temperatures and pressures, as well as at elevated accelerations. As an example of its utility, the first results obtained for the viscosity of DGG-1 glass under pressure are presented. This device will enable the determination of the viscosity of volatile-bearing silicate melts in the mid- to high-viscosity range (10⁶-10⁹ Pa s) that is otherwise very difficult to access. Additionally, experimental investigations of physics and chemistry of the segregation of water-bearing melts from partially molten rocks under conditions of enhanced acceleration are now possible.