PROTO-SPHERA is a project that the Italian National Agency for New Technologies, Energy, and Sustainable Economic Development (ENEA) commissioned Reynolds Polymer’s proprietary acrylic for in order to utilize the outstanding strength and optical clarity. This project is an innovative Magnetic Confinement plasma experiment for Controlled Thermonuclear Fusion research, whose aim is to form a Spherical Torus confinement plasma not around a metal centerpost (as in Tokamaks), but around a plasma centerpost.
The PROTO-SPHERA experiment is plasma producing. Magnetic plasma instabilities will kink the plasma centerpost to a point such as to produce the Spherical Torus around it. This confinement scheme, if successful, will have advantages over Tokamaks: cylindrical and not toroidal geometry of the vacuum vessel (easing access and repairs), undefined sustainment of the toroidal current within the Torus, by DC voltage applied to the plasma centerpost (allowed by mixed magnetic and electrostatic plasma confinement and major role of plasma mass motion), finally high plasma beta (unitary ratio between plasma pressure and magnetic confinement pressure, which in Tokamaks is only a few %), that would minimize the size of a future Fusion reactor.
Reynolds Polymer’s proprietary acrylic was used to create the cylinder that become the house of the experiment, as its material properties and characteristics are able to handle a base pressure of about 2•10^-4 mbar.