Luminescence from NaI(Tl) between 5°K and 30°K

The several emission bands of scintillator crystal NaI(TlI) excited by X-irradiation have been studied between 5° and 80°K. It was possible to trap electrons as Tl° and holes as I2- and Tl++ during irradiation and cause recombination thermally or by optical stimulation after irradiation to give the same emissions. The processes responsible for recombination after irradiation are discussed and assignments based on these results made for processes during irradiation.