title: Evaluation of solid state nuclear track detector stacks exposed on the international space station.
abstract: The aim of the study was to investigate the contribution of secondary neutrons to the total dose inside the International Space Station (ISS). For this purpose solid-state nuclear track detector (SSNTD) stacks were used. Each stack consisted of three CR-39 sheets. The first and second sheets were separated by a Ti plate, and the second and third sheets sandwiched a Lexan polycarbonate foil. The neutron and proton responses of each sheet were studied through MC calculations and experimentally, utilising monoenergetic protons. Seven stacks were exposed in 2001 for 249 days at different locations of the Russian segment 'Zvezda'. The total storage time before and after the exposure onboard was estimated to be seven months. Another eight stacks were exposed at the CERF high-energy neutron field for calibration purposes. The CR-39 detectors were evaluated in four steps: after 2, 6, 12 and 20 h etching in 6 N NaOH at 70 degrees C (VB = 1.34 microm h(-1)). All the individual tracks were investigated and recorded using an image analyser. The stacks provided the averaged neutron ambient dose equivalent (H*) between 200 keV and 20 MeV, and the values varied from 39 to 73 microSv d(-1), depending on the location. The Lexan detectors were used to detect the dose originating from high-charge and high-energy (HZE) particles. These results will be published elsewhere.
authors.affiliation: KFKI, Atomic Energy Research Institute, P.O.Box 49, H-1525 Budapest, Hungary. palfalvi@sunserv.kfki.hu
authors.forename: J K
authors.initials: JK
authors.lastname: Pálfalvi
authors.forename: Yu
authors.initials: Y
authors.lastname: Akatov
authors.forename: J
authors.initials: J
authors.lastname: Szabó
authors.forename: L
authors.initials: L
authors.lastname: Sajó-Bohus
authors.forename: I
authors.initials: I
authors.lastname: Eördögh
mesh_terms: D001822:Body Burden; D003359:Cosmic Radiation; D004781:Environmental Exposure / Q000032:analysis; D004867:Equipment Design; D019544:Equipment Failure Analysis; D038622:Internationality; D009502:Neutrons; D016273:Occupational Exposure / Q000032:analysis* / Q000706:statistics & numerical data*; D011829:Radiation Dosage; D011835:Radiation Protection / Q000379:methods; D011868:Radioisotopes / Q000032:analysis; D011874:Radiometry / Q000295:instrumentation* / Q000379:methods; D012062:Relative Biological Effectiveness; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013026:Space Flight / Q000295:instrumentation* / Q000379:methods; D014159:Transducers
chemical_list: D011868:Radioisotopes