Accession Number : AD0464281


Title :   DOSIMETRY FOR LARGE ANIMAL EXPERIMENTS USING MULTIPLE CO60 SOURCES AND 1 MVP X-RAYS


Corporate Author : NAVAL RADIOLOGICAL DEFENSE LAB SAN FRANCISCO CA


Personal Author(s) : Menkes, Cirel K


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/464281.pdf


Report Date : 08 Jun 1965


Pagination or Media Count : 32


Abstract : A quadrilateral configuration of four movable uncollimated Co60 sources with a total activity of 9,000 curies was used to obtain exposure measurements in air and depth doses in a masonite phantom for radiation experiments involving sheep. The depth dose distribution in the phantom in the four source exposure is compared to distributions obtained using a single collimated Co60 source four times in succession to simulate the four source array and exposure geometry, and to 1 Mvp X-rays in a bilateral exposure. Distributions of the quadrilateral gamma and x-ray exposures differed quantitatively but no more than 5% throughout the phantom thickness. Ionization measurements were made in outdoor pens built to house one hundred sheep individually during chronic low-level exposures ranging from 500 mR/hr. Exposure rates at the two rows of pens were varied by using several source arrangements. Bilateral depth dose distributions in a sheep phantom exposed in the pens showed that the radiation from the uncollimated sources at the distance of the pens was less penetrating than from a collimated Co60 source at a closer distance (corrected for universe square effect), and more penetrating than from 1 Mvp X- rays except at the phantom surfaces.


Descriptors :   *DOSIMETERS , *RADIOACTIVITY , MAMMALS , DISTRIBUTION , X RAYS , PENETRATION , LABORATORY ANIMALS , IONIZATION , RADIOACTIVE ISOTOPES , RADIATION DOSAGE , COBALT , MEASUREMENT , SOURCES , GAMMA RAYS


Subject Categories : Nuclear Instrumentation


Distribution Statement : APPROVED FOR PUBLIC RELEASE