THE DEVELOPMENT OF LARGE BETA RADIATION SOURCES AND THEIR APPLICATIONS

Technical Report · Mon Jul 01 04:00:00 EDT 1963

OSTI ID:4172772

Weinstock, J J; Miron, Y; Krishna, P M

An extensive research and development program produced vitreous enamel formulations suitable for the fabrication of large planar beta radiation sources using promethium-147, cerium-144, or strontium-90 as the active component. The physical and chemical properties of these enamels were characterizend, and actual source dosimetry patterns were established for Pm/sup 147/ and Ce/sup 144/ sources. A parallel study developed an attractive radiation-induced graft polymerization process for modifying the properties of polypropylene films and fabrics which is ideally suited fot the use of large beta sources. Over 60 different enamel formulations were prepared and evaluated with respect to coating (enameling) characteristics, resistance so attach by various solvents and aqueous solutions, and resistance to thermal and mechanical shock. The best forNonemulations developed contain 24 weight per-cent of the active component (SrO, CeOz, or Pm2O/sub 3/) 51% SiO/sub 2/, and varying amounts of 9 other ingredients. They are more resistant to chemical attack than pyrex glass, and they can withstand considerable thermal and mechanical shocks (repeated quenches at temperature differences of over 600 deg F and repeated point impacts of over 1b inchpounds). These enamels allow the fabrication of beta sources containing up to 5 curies per square centimeter of Pm/sup 147/ in a 4-mil thick coating, up to 5 C/cm/sup 2/ of Ce/sup 144/ in an 8-mil coating, and up to 1 C/cm/sup 2/ of Sr/sup 90/ in in 8-mil coating. Such sources will deliver surface and near surface dose rates in the range of 1 to 10 megarads per hour. Actual dosimetry patterns are presented for enameled Ce/sup 144/ and Pm/sup 147/ sources containing approximately 0.1 millicurie per square centimeter. These dosimetiy measurements are compared with theoretical calculations and show generally good agreement. Since isotopic beta sources cand be fabricated so as to deliver uniform dose rates over large areas, the study of potential beta source applications concentrated on the modification of the properties of various plastic films and synthetic fabrics by meands of radiation-induced graft polymerization. A number of system; were experimentally screened, and a single system----a copolymer methacrylic acid-styrene graft on polypropylene--was investigated in some detail. The effects of a number of process variables are defined (e.g., ments, etc.), and properties of the resulting grafted samples are given. Excellent dyeability of grafted polypropylene fabric was demonstrated. (auth) Information is presented on the range of radioisotopes and sources being produced in Australia. The packing and transport of radioisotopes are described. Specifications and prices are presented for unprocessed and processed radioisotopes. Radiography sources and Co/sup 60/ sources are also described. The irradiation, activation, and tritiation services and the advisory and consulting service are discussed. (D.L.C.)

• Research Organization: Radiation Applications Inc., Long Island City, N.Y.
• NSA Number: NSA-18-000516
• OSTI ID: 4172772
• Report Number(s): RAI-202
• Country of Publication: United States
• Language: English

Related Subjects

BETA PARTICLES
CERAMICS
CERIUM 144
CERIUM OXIDES
CHEMICAL REACTIONS
COATING
DOSEMETERS
EFFICIENCY
ENAMELS
FILMS
GRAFTS
IMPACT SHOCK
ISOTOPE TECHNOLOGY
METHACRYLIC ACID
PARTICLE SOURCES
POLYMERIZATION
POLYMERS
PRODUCTION
PROMETHIUM 147
PROMETHIUM OXIDES
PROPYLENE
RADIATION SOURCES
SILICON OXIDES
SOLUTIONS
SOLVENTS
STABILITY
STRONTIUM 90
STRONTIUM OXIDES
STYRENE
THERMAL STRESSES
TRANSPLANTS
USES
WATER