Ionoluminescence induced by 3 MeV He+ ions on as-grown and pre-damaged BaMgF4 crystals

The ionoluminescence (IL) spectra and yields have been investigated on pristine and pre-damaged crystals of BaMgF4, using a He probe beam at 3 MeV. The previous lattice damage has been produced by irradiation with Br ions at 15 MeV in the electronic stopping regime (Se=5.8 keV/nm⪢Sn) and has been monitored by Rutherford-backscattering spectrometry in the channeling configuration (RBS/C). The IL spectra covering the wavelength range from 250 nm to 800 nm (∼1.5–5 eV) are similar for pristine and pre-irradiated crystals, but the IL emission yields exhibited a marked decrease with pre-irradiation fluence. A good correlation between such decrease and the generated structural damage has been established. Possible mechanisms for this behavior are discussed.