3200 ANGSTROM PHOSPHOR

The objective of the research was to lead to the production of a cathodoluminescent phosphor which emits with high efficiency in the spectral region around 3200 A. This phosphor is to be incorporated into very high resolution cathode-ray tubes with fiber optic faceplates for data recording on UV sensitive, dry-process film. Most of the effort during this period went into phosphor synthesis and preliminary evaluation, and a large number of experimental samples was prepared. Preparation and processing of zinc orthosilicate doped with titanium dioxide was completed. UV luminescent BaSiO3:Tl and Ba2SiO4:Tl were synthesized and shown to luminesce with reasonable efficiencies at low excitation densities but to lose efficiency rapidly with increasing current densities. They were therefore judged to be unsatisfactory materials. BaSi2O5 could not be successfully doped with thallium. BaZnSi4O10:Pb was investigated further and the optimum firing temperature was determined. Experiments were begun on SrCaZnSi2O7:Pb. These latter two materials emit at 3100 and 3350 A, respectively, and continue to look quite promising. Changes were made in the experimental apparatus for measuring phosphor efficiencies and maintenance in order to provide greater protection to the operator from stray X-radiation, to allow operation with less attention, and to prevent interference with the tests by X-ray solarization of the faceplates. (Author)