| 摘要 |
<p>In the production of radiographs the use of a silver halide photographic material for exposure with an X-ray image fluorescent intensifying screen, characterized in that(1) the silver halide photographic material comprises a support and silver halide that is capable of producing in said material a negative silver image having a covering power greater than about 50 said silver halide being present in an equivalent concentration of less than about 0.080 g of silver per sq.dm, and(2) the X-ray image fluorescent intensifying screen contains a phosphor layer comprising a phosphor or a phosphor mixture consisting wholly or mainly of a rare earth metal-activated lanthanum oxychloride or lanthanum oxybromide, said phosphor or phosphor mixture having more than half its spectral emission above about 410 nm, more than half its visible light spectral emission between 400 and 500 nm and its maximum peak emission below 500 nm and wherein said phosphor layer has a coverage of said lanthanum oxyhalide phosphor of 100 to 800 g per sq.m and said screen material has an intensification factor of at least 20 at 40 kV and at least 25 at 80 kV, this intensification factor being at least 2 times as high as that of an europium-activated barium strontium sulphate phosphor layer having substantial identity with regard to layer thickness, binder composition, phosphor particle size and phosphor content per sq. m.</p> |
