FRP surfaces and frictional properties of structural materials in superconducting coils

To make spacers from a plate made of the Dyneema fiber reinforced plastic (DFRP), a diamond cutter is generally used. When the plate is cut, the many agnail-like Dyneema fibers remain on the face. Hence we polished the face and measured the frictional coefficients on the faces with and without the agnail-like fibers. According to the experimental results the frictional coefficients on the surfaces with/without the Dyneema fibers showed almost the same value at the cryogenic temperatures (77 and 4 K). Therefore, during fabricating process of spacers made of DFRP, it is not necessary to polish the surfaces of DFRP spacers and to remove the agnail-like fibers after cutting the spacers from a viewpoint of the frictional coefficients. [Copyright &y& Elsevier]