sulfur hexafluoride

Because SF6 is relatively slowly absorbed by the bloodstream, it is used to provide a long-term tamponade or plug of a retinal hole in retinal detachment repair operations. In a further medical application, SF6 is employed as a contrast agent for ultrasound imaging. Sulfur hexafluoride microbubbles are administered in solution through injection into a peripheral vein. These microbubbles enhance the visibility of blood vessels to ultrasound. This application has been utilized to examine the vascularity of tumours amongst other things. Sulfur hexafluoride is also used as a reagent for creating thrust in a closed Rankine cycle propulsion system, reacting with solid lithium as used in the United States Navy's Mark 50 torpedo. SF6 plasma is also used in the semiconductor industry as an etchant. The magnesium industry uses large amounts of SF6 as inert gas to fill casting forms. Sulfur hexafluoride is also used to pressurize waveguides in radar systems. SF6 is also used as an alternative to oil in insulating high voltage equipment such as power transformers and switchgear.