title: Measurement of anisotropic angular distributions of photon energy spectra for I-125 brachytherapy sources.
abstract: The angular distribution of photon energy spectra emitted from an I-125 brachytherapy source was measured using a specially designed jig in the range of ±70° in the plane of the long axis of the source. It is important to investigate the angular dependence of photon emissions from these sources for the calibration of the air kerma rate. The results show that the influence of the distributions between 0° and ±8° is small enough to allow a calibration using current primary instruments which have a large entrance window.
authors.affiliation: National Metrology Institute of Japan, Tsukuba, Ibaraki, Japan. y.unno@aist.go.jp
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Unno
authors.forename: Akira
authors.initials: A
authors.lastname: Yunoki
authors.forename: Tadahiro
authors.initials: T
authors.lastname: Kurosawa
authors.forename: Takahiro
authors.initials: T
authors.lastname: Yamada
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Sato
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Hino
mesh_terms: D016880:Anisotropy; D001918:Brachytherapy / Q000295:instrumentation*; D007457:Iodine Radioisotopes / Q000032:analysis* / Q000627:therapeutic use*; D017785:Photons; D011874:Radiometry / Q000379:methods*; D011879:Radiotherapy Dosage; D012542:Scattering, Radiation
chemical_list: D007457:Iodine Radioisotopes