Measuring the Viscosity of Sulphur Melt by the Proton Microscopy Method

Sulfur is a substance with an abnormal dependence of viscosity on temperature. An experimental setup was created to study the viscosity of sulfur at pressures up to 100 bar and temperatures up to 500 °C. To visualize the process of falling of a tungsten carbide ball located in molten sulfur, the proton radiography method was used. The experiment was carried out on a PRIOR-II proton microscope (Institute for Heavy Ion Research, GSI, Darmstadt, Germany). In this experiment, the operating mode of the SIS-18 accelerator with slow beam extraction was used for the first time for proton radiography. The viscosity of the sulfur melt was measured at a pressure of 90 bar and temperatures of 190—320 °C. It has been shown that the viscosity of sulfur is greatly influenced by impurities, including hydrogen sulfide, which appears in the molten sulfur at high temperatures.