INVESTIGATION OF CRYOGENIC IRRADIATION INFLUENCE ON MECHANICAL AND PHYSICAL-PROPERTIES OF ITER MAGNETIC SYSTEM INSULATION MATERIALS

A set of methods of cryogenic irradiation influence test on mechanical and physical properties of insulation of ITER, magnetic system are pr esented in this paper. Investigations are carried out without intermed iate warming up of samples, A Russian insulating composite material wa s irradiated in the IVV-2M Reactor. The ratio of energy absorbed lay i nsulation materials from neutron irradiation to that from gamma irradi ation can be varied from similar to(25:75)% to similar to(50:50) % in the Reactor. The test results on the thermal expansion, thermal conduc tivity and gas evolution of the above material, are presented. It was shown, that cryogenic irradiation up to the fluence similar to 2 x 10( 22) n/m(2) (E greater than or equal to 0.1 MeV) leads to 0.27% linear size changes along layers of fiber-glass, the thermal conductivity coe fficient is decreased on 15% at 100 k in perpendicular direction to fi ber-glass plane, and thermal coefficient of linear expansion (TCLE) ha s anomalous temperature dependence. (C) 1998 Elsevier Science B.V. All rights reserved.