Glass-fibre-reinforced plastics with 73 vol% glass content have been d
eveloped with improved mechanical and thermal properties in the lamina
ted direction. The thermal contraction down to liquid-helium temperatu
re and the Young's modulus at room temperature in the laminated direct
ion were 0.3% and 23 GPa, respectively. The interlaminar shear strengt
h (ILSS) measured by the short-beam shear method at liquid-nitrogen te
mperature was confirmed not to decrease with increasing glass content.
The change in ILSS induced by electron irradiation was also studied.
Approximately a 50% decrease in ILSS was brought about by 20 MGy irrad
iation. The applicability of the material for large-scale superconduct
ing magnets is discussed.