Specific features of the influence of high-energy electron beams on the luminescent properties of undoped and Nb, Fe-doped Al₂O₃ crystals.
The influence of 10 MeV high-current electron beams accelerated by the M-30 microtron on the luminescent properties of the α-Al₂O₃, Al₂O₃:Nb and Al₂O₃:Fe crystals has been studied. The effect of the long-term phosphorescence at room temperature has been found that can be used to monitor electron and gamma accelerator beams.
Monitoring and surveillance of radio-cesium in cultivated soils and foodstuff samples in Israel 18 years after the Chernobyl disaster
Abstract The concentration of radio-cesium and radio-beryllium in foodstuff and soils samples was measured together with natural radioactivity ( 40 K and Th, U chains) in Marinelli (reentrant) beakers using γ -ray spectrometry. Radio-cesium in foodstuff and soils samples varies from 0.1 to 0.5 and from 1.5 to 20 Bq kg - 1 , respectively. The limit of detection for determination of radio-cesium was found to be 0.04 Bq (i.e. 1.1 pCi). The concentration of radio-cesium measured in dry milk powders, concentrated from composite raw, whole milk samples varies from 0.05 to 0.08 Bq kg - 1 . The level of radiation of 137 Cs measured in foodstuff samples presents no potential health hazard to the public today in any conceivable way as they are much smaller than the natural contribution.
Anomalous Annealing Behavior of Arsenic Implanted Silicon as a Function of Dose and Energy
Anomalous annealing behavior of damage in As implanted Si has been investigated by channeling effect measurements. Room temperature As implants with doses from 1014 to 2 × 1016cm-2 at energies ranging from 50 to 250 keV into Si were annealed over the range of 600°C to 1100°C. Anneal temperatures ≥ 950°C reduce the disorder for ion doses of 0.5 to 1 × 1016 cm-2 at energies between 50 and 250 keV. Anomalously high residual disorder was found for the intermediate doses of 2 × 1014 to 2 × 10/cm2 implanted above 100 keV. For this intermediate dose, annealing of implants performed at liquid nitrogen temperatures did not show significant reduction in this damage. However implants at 200° to 300°C indicate a lower amount of damage compared to the room temperature implants.