Development and study on putties for cryogenic coils of the ''T-15'' thermonuclear device

The paper deals with the development and study on putties intended for smoothing out the surfaces and scaling cryoresistive conductors and superconductors in the electromagnetic system coils of the ''T-15'' tokamak devices. The studies covered the effect of the putty compositions on electric insulating, mechanical, technological propertieS, as well as the determination of their resistance to thermal shocks and subsequent changes in the properties. The objects of the studies are putty compositions produced on the base of epoxy dianil resin hardened by isomethyltetraphthalic acid anhydride. Boron nitride, talc, grinded mica, boron carbide and their mixture are fillings. An analysis of the experimental data permits to make conclusion that among the studied putty compositions most suitable, according to the set of properties, for smoothing out the superconducting surfaces in cryogenic coils is a putty on the base of EhD-22 resin with the filler of a mixture of ground mica and tals. This putty has high mechanical and electrical strength parameters, satisfactory technological properties. After hardening it permits to get a solid insulation system. The putty mechanical strength losses after 150 thermal chock cycles are 10-20%