Recombination gamma-luminescence at the nanometal Li – dielectric LiF interfaces

• GL band at 420 nm (F-center at Cu impurity) decreases 5 times from 105 to 107 R.
• GL band at 570 nm increases due to F-centers aggregation to F4+ at >106 R, >370 K.
• GL at the Li–LiF interface accompanies growth of nano-Li from mobile Li vacancies.

Recombination 60Co-gamma-luminescence (GL) was studied experimentally in LiF:K,Cu crystals at the dose rate 406 R/s in the temperature range 273–473 K, when localized charge carriers are released from the hole/electron color center traps and Li vacancies are highly mobile. The crystals were preliminary irradiated in the 60Co gamma-source at 300–320 K to doses 107, 108, 109 R to generate F-aggregate centers and nano-colloids of Li. The intensity of GL bands at 570 nm (F4 centers) and 670 nm (F2+ centers) was shown to increase after 106 R above 370 K due to dominant contribution from radiative recombination of the released carries at the interface of nanometal-Li–dielectric-LiF. These bands can be used for gamma-dose measurements at 107–108 R.