title: Observation of gamma-rays from fallout collected at Ibaraki, Japan, during the Fukushima nuclear accident.
abstract: Gamma-ray pulse height distributions were measured for a fallout sample collected at Ibaraki, Japan, during the Fukushima accident in March 2011. The fallout was collected in a pan of water and then evaporated to dryness on a stainless-steel holder. The sample was measured by a germanium detector three times over a year. In the pulse height distribution of the initial measurement, approximately 140 peaks were observed in the 50-2048 keV energy region. Most of these peaks were either total absorption peaks or sum peaks of Te, I or Cs isotopes. Unlike fallout samples at the past nuclear accidents, nuclides such as Ce and Ru were not detected whereas (110m)Ag was prominently observed. The radioactivity concentration of (137)Cs was determined to be at least 1.4×10(4) Bq m(-2), approximately 14% of which was attributed to rainout.
authors.affiliation: Fukushima Environmental Safety Center, Headquarters of Fukushima Partnership Operations, Japan Atomic Energy Agency, 7F, NBC-Unix Building, 6-6 Sakae-machi, Fukushima 960-8031, Japan. saegusa.jun@jaea.go.jp
authors.forename: Jun
authors.initials: J
authors.lastname: Saegusa
authors.forename: Yasuaki
authors.initials: Y
authors.lastname: Kikuta
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Akino
mesh_terms: D062406:Fukushima Nuclear Accident; D005720:Gamma Rays; D011829:Radiation Dosage; D011834:Radiation Monitoring / Q000379:methods*; D011847:Radioactive Fallout / Q000032:analysis*; D013048:Specimen Handling / Q000379:methods
chemical_list: D011847:Radioactive Fallout