Patent ID: 8535434

Claim:
A material in form of lithium fluoride powder characterized by: comprising particles having an average size of 160 nm and a size distribution that can be approximated by a Gaussian curve centred at said average size value and having a width at half height of 195 nm; having a colour centre content comprised from 1×10 16 Colour Centre (CC)/cm 3 to 1×10 19 (Colour Centre (CC)/cm 3 ; and having an emission spectrum with a characteristic shape and two peaks centered at 542 nm and 660 nm obtained with a beam of non-monochromatized radiation of an energy comprised from 3 to 15 keV and characterized by an intensity not less than 1×10 11 photons/s/mm 2 , with a total dose comprised between 10 14 and 10 17 photons.