Radiation intensity and expansion saturation of the crystal lattice of irradiated diamond

It is shown that the saturation of the expansion of the diamond crystal lattice during irradiation in a reactor depends not only on the temperature but also on the intensity of the irradiation. Expansion saturation decreases with decreasing irradiation intensity. The temperature influences saturation expansion indirectly via an increase of the effectiveness of the annealing of defects, and the intensity of irradiation stimulates additional annealing by increasing its duration. The same level of the saturation of expansion of the diamond lattice, specifically, 2.75%, can be attained at irradiation temperatures 80 and 300°C if the diamond is irradiated with neutron flux density 10 12 and 10 14 sec –1 ·cm –2 , respectively.