X-ray image intensifier tube and x-ray conversion screen containing terbium activated silicate luminescent glasses
AssigneeLockheed Missiles & Space Company, Inc.
InventorsRobert A. Buchanan, Clifford Bueno
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Abstract
This invention relates to terbium activated silicate luminescent glasses exhibiting reduced afterglow and enhanced luminescence due to incorporation therein of selected rare earth oxides of cerium, europium and gadolinium.
Claims12
An x ray image intensifier comprising an input screen consisting essentially of a fiber optic scintillating plate of a luminescent terbium-activated silicate glass exhibiting reduced phosphorescence and background buildup and enhanced luminescent responsivity under x-ray illumination energy between about 5 keV to 16 MeV and consisting essentially, by weight on the oxide basis, of about 3-25% R.sub.2 O, wherein R.sub.2 O consists of 0-5% Li.sub.2 O, 0-25% Na.sub.2 O, 0-25% K.sub.2 O, 0-25% Rb.sub.2 O and 0-25% Cs.sub.2 O;
- 5-55% RO wherein RO consists of 0-20% MgO, 0-30% CaO, 0-45% SrO and 0-55% BaO;
- 35-70% SiO.sub.2 ;
- 0-20% R.sub.2 O.sub.3 wherein R.sub.2 O.sub.3 consists of 0-20% La.sub.2 O.sub.3 and 0-15% Y.sub.2 O.sub.3 ;
- oxide selected from the group consisting of cerium oxide and europium oxide;
- 5-20% Tb.sub. 2 O.sub.3 ;
- and 1-15% Gd.sub.2 O.sub.3.
A glass x-ray conversion screen consisting essentially of a luminescent, terbium-activated silicate glass exhibiting reduced phosphorescence and background buildup and enhanced luminescent responsivity under x-ray illumination energy between about 5 keV to 16 Mev and consisting essentially, by weight on the oxide basis, of about 3-25% R.sub.2 O wherein R.sub.2 O consists of 0-5% Li.sub.2 O, 0-25% Na.sub.2 O, 0-25% K.sub.2 O, 0-25% Rb.sub.2 O and 0-25% Cs.sub.2 O;
- 5-55% RO wherein RO consists of 0-20% MgO, 0-30% CaO, 0-45% SrO and 0-55% BaO;
- 35-70% SiO.sub.2 ;
- 0-20% R.sub.2 O.sub.3 wherein R.sub.2 O.sub.3 consists of 0-20% La.sub.2 O.sub.3 and 0-15% Y.sub.2 O.sub.3 ;
- 0.1-2% of at least one oxide selected from the group consisting of cerium oxide and europium oxide;
- 5-20% Tb.sub.2 O.sub.3 ;
- and 1-15% Gd.sub.2 O.sub.3.
An x-ray conversion screen consisting essentially of a fiber optic scintillating plate of a luminescent terbium-activated silicate glass exhibiting reduced phosphorescence and background buildup and enhanced luminescent responsivity under x-ray illumination energy between about 5 keV to 16 MeV and consisting essentially, by weight on the oxide basis, of about 3-25% R.sub.2 O wherein R.sub.2 O consists of 0-5% Li.sub.2 O, 0-25% Na.sub.2 O, 0-25% K.sub.2 O, 0-25% Rb.sub.2 O and 0-25% Cs.sub.2 O;
- 5-55% RO wherein RO consists of 0-20% M.sub.g O, 0-30% CaO, 0-45% SrO and 0-55% BaO;
- 35-70% SiO.sub.2 ;
- 0-20% R.sub.2 O.sub.3 wherein R.sub.2 O.sub.3 consists of 0-20% La.sub.2 O.sub.3 and 0-15% Y.sub.2 O.sub.3 ;
- 0.1-2% of at least one oxide selected from the group consisting of cerium oxide and europium oxide;
- 5-20% Tb.sub.2 O.sub.3, and 1-15% Gd.sub.2 O.sub.3.
Dependencies are inferred from the claim text.