title: Nationwide survey on the operational status of medical compact cyclotrons in Japan.
abstract: The management of induced radioactivity of the cyclotron itself and structures is an important issue in decommissioning of medical compact cyclotrons. To obtain basic data on the actual operational conditions of cyclotrons, we performed nationwide survey. The actual beam current was about half of the maximum beam current indicated in the official permits for cyclotron operation. The actual operating time was about 10% of the maximum operating time indicated in the official permits. The average daily radioactive-nuclide ((18)F) production was only 10% of the allowed maximum quantity. From these results, it became clear that the induced radioactivity of a cyclotron and its concrete structures based on the maximum beam current and the maximum operating time may be overestimated. These basic data are expected to be useful for a realistic evaluation and helpful in establishing a rational regulation in regard to radioactive waste control for decommissioning of medical cyclotrons.
authors.affiliation: Department of Radiological Sciences, School of Health Sciences, Ibaraki Prefectural University, Inashiki-gun, Ibaraki, Japan. fujibuchi@ipu.ac.jp
authors.forename: Toshioh
authors.initials: T
authors.lastname: Fujibuchi
authors.forename: Ichiro
authors.initials: I
authors.lastname: Yamaguchi
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Watanabe
authors.forename: Ken-ichi
authors.initials: K
authors.lastname: Kimura
authors.forename: Shinji
authors.initials: S
authors.lastname: Tanaka
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Kida
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Nagaoka
mesh_terms: D017357:Cyclotrons / Q000706:statistics & numerical data*; D003625:Data Collection; D006801:Humans; D007564:Japan; D011834:Radiation Monitoring / Q000706:statistics & numerical data*; D011868:Radioisotopes; D012449:Safety / Q000706:statistics & numerical data; D013997:Time Factors
chemical_list: D011868:Radioisotopes
references.citation: Health Phys. 1994 Dec;67(6):621-31
references.pmid: 7960783