Other

US Government As Represented by the Secretary of the Army

The United States of America As Represented by the Secretary of

William L McLaughlin

Stanley Kronenberg

Carl R Siebentritt

Harry Levine

Walter J Chappas

Marvin Rosenstein

Mahnaz Farahani

Carl R Seibentritt, Jr

Mohamed I Al-Sheikhly

A radiation dosimeter includes an optical waveguide enclosing a radiation-sensitive material that changes color or color intensity with increasing amounts of exposure to high energy ionizing radiation. A light-transparent radiation-transparent light-transmitting member extends along the length of the optical waveguide, and is separated from the radiation-sensitive material by a light-opaque sidewall. Outside the light-transmitting member is a light-opaque shield that permits light to enter distal ends of the waveguide and the light-transmitting member, while permitting light to exit the proximal ends thereof, the light-opaque shield being transparent to high energy ionizing radiation. A light transmission comparator is positioned adjacent the proximal end of the light-transmitting member, the comparator including a plurality of transparent segments of different color or color intensity arranged in an array of consecutive light-to-dark shades, the color or color intensity of each segment being an exact reproduction of an actual dose level coloration that results from exposure of the radiation-sensitive material within the waveguide of a particular dose of radiation, so as to provide for accurate determination of radiation exposure to the optical waveguide under a variety of ambient lighting conditions.

Color-matched, ambient-light visual comparator dosimeter

A radiological measuring instrument including an angularly variable radiation sensitive structure comprised of two blocks of material having a different index of refraction with one of the materials comprising a radiochromic substance whose refractive index changes through anomolous dispersion as a result of being exposed to radiation. The ratio of the two indices of refraction is selected to be close to unity, with the radiation sensitive structure being pivotally adjusted so that light is directed into one end of the block comprising a material having the greater index of refraction. This element, moreover, is selected to be clear and transparent with the incident angle being close to the critical angle where total reflection of all incident light occurs. A portion of the incident light is furthermore projected through the clear transparent block without reflection, with the two beams emerging from the other end of the block, where they are detected. Exposure to radiation changes the index of refraction of the radiochromic block and accordingly the reflected energy emerging therefrom. Calibrated readjustment of the angle of incidence provides a measure of the sensed radiation.

Radiological instrument

A radiochromic leuko dye dosimeter includes a plastic tube containing a solution of a radiochromic dye which is sensitive to ionizing radiation, one end of the tube being closed by a reflective surface, the opposite end of the tube being closed by a transparent plug to form a one-way optical waveguide. Light enters the tube through the transparent end thereof and is reflected back and exits through the transparent end. The intensity of the exiting light is measured to determine radiation induced absorption of the leuko dye.

Radiochromic leuko dye real time dosimeter, one way optical waveguide

An optical waveguide dosimeter for personnel dosimetry is provided including a liquid solution of leuko dye hermetically sealed in plastic tubing. Optical transport is improved by dipping the ends of the plastic tubing into clear epoxy, thus forming beads that serve as optical lenses. A layer of clear ultraviolet absorbing varnish coated on these beads and an opaque outer layer over the plastic tubing provides protection against ambient UV.

Optical waveguide dosimeter

A hard, clear, glassy, smooth polymer with a dry surface having a dye precursor therein which forms a permanent color at those areas of the solid polymer that have been irradiated with ultra-violet or ionizing radiation is formed by combining vinyl and/or acrylic monomers, a triphenylmethane cyanide dye precursor and a chemical initiator that is compatible with the dye cyanide and polymerizing in the presence of a slight excess of hydrogen ions in an inert atmosphere.

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Washington, DC, United States of America

William L McLaughlin