AbstractThe thermoluminescental investigations of neutron and gamma irradiated lithium orthosilicate pellets were carried out. It has been shown that the addition of Cr3+ and Fe3+ ions with the total concentration up to 2.0 wt.% during preparation of lithium orthosilicate pellets, significantly reduces the formation of radiation defects in irradiated matrix. This phenomena can be explained by the reducing of the formation of primary radiation defects during irradiation due to stimulating the recombination processes by the ions of impurities. Several ion concentration combinations were studied. The thermoluminescental investigations of fast neutron irradiated lithium orthosilicate pellets in the presence of external magnetic fields were carried out. It has been shown that the magnetic field increases the role of more thermal stable peaks in the total thermoluminescence yield.