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The radioluminescence and thermoluminescence spectra of synthetic zircon crystals doped with individual trivalent rare earth element (REE) ions (Pr, Sm, Eu, Gd, Dy, Ho Er, and Yb) and P are reported in the temperature range 25 to 673 K. Although there is some intrinsic UV/blue emission from the host lattice, the dominant signals are from the rare-earth sites, with signals characteristic of the REE 3+ states. The shapes of the glow curves are different for each dopant, and there are distinct differences between glow peak temperatures for different rare-earth lines of the same element. Within the overall set of signals there are indications of linear trends in which some glow peak temperatures vary as a function of the ionic size of the rare earth ions. The temperature shifts of the peaks are considerable, up to 200°, and much larger than those cited in other rare-earth-doped crystals of LaF 3 and Bi 4 Ge 3 O 12 . The data clearly suggest that the rare-earth ions are active both in the trapping and luminescence steps, and hence the TL occurs within localized defect complexes that include REE 3+ ions.

Sapphire (AlzO,) and silica samples have been implanted with 400 keV europium ions at fluences between 5X 1014 and 1 X 10"' ions cm-*. As-implanted, samples show luminescence at 622 nm, and although the intensity may be increased by furnace anneals up to 1000 "C, higher temperatures, to 1200 "C, result in less emission, as the impurity ions form precipitate clusters. This problem can be avoided by the use of pulsed laser anneals which dissociate the clusters and quench in atomically dispersed ions. The luminescence intensity has been increased by factors of 95 and 85 for sapphire and silica, respectively, relative to the initial implanted signal. On comparing with furnace anneals at 1200 'C, the pulsed laser annealing is more effective, by factors of up to 45 times. Data for pulsed excimer and CO2 lasers are compared. Both types of laser appear to remove the ion-implanted radiation damage, but in the case of silica, higher luminescence performance was obtained with the excimer anneals. There was no evidence for diffusion of the implanted em-opium, as assessed by Rutherford backscattering spectrometry. 0 I995 American Institute of Physics.

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