ANNIHILATION OF FAST-NEUTRON DEFECTS IN LI-BETA-ALUMINA CERAMICS

The effect of fast neutron bombardment (2 Mev Cf-252 source) With flue nce of 1.07 x 10(18) n/cm2 on the linear thermal expansion of Li-beta- alumina ceramics was studied. Two ceramic groups in which the contents of oxides of Li, Na, K as well as B increased at the expense of alumi na were prepared. Induced defects in terms of X-ray diffraction analys is were discussed to assess the use and applicability of these ceramic s in neutron dosimetry. The thermal expansion data indicated that both groups exhibited reduction in the mean thermal expansion coefficient values upon irradiation. This is parallel with the shift in the lattic e planes of the group with higher alumina and amorphism in the other o ne. Annealing of the neutron induced defects at 1000 degrees C denoted that partial recovery in higher aluminous group is detected. Approxim ately complete recovery in the other group revealed a higher state of metamictization.