title: Radiation dose from reentrant electrons.
abstract: In estimating the crew exposures during an extra vehicular activity (EVA), the contribution of reentrant electrons has always been neglected. Although the flux of these electrons is small compared to the flux of trapped electrons, their energy spectrum extends to several GeV compared to about 7 MeV for trapped electrons. This is also true of splash electrons. Using the measured reentrant electron energy spectra, it is shown that the dose contribution of these electrons to the blood forming organs (BFO) is more that 10 times greater than that from the trapped electrons. The calculations also show that the dose-depth response is a very slowly changing function of depth, and thus adding reasonable amounts of additional shielding would not significantly lower the dose to BFO.
authors.affiliation: NASA Lyndon B. Johnson Space Center, SN, 2101 NASA Road 1 Houston, TX 77058-3696, USA. gautam.d.badhwar@jsc.nasa.gov
authors.forename: G D
authors.initials: GD
authors.lastname: Badhwar
authors.forename: J
authors.initials: J
authors.lastname: Watts
authors.forename: T E
authors.initials: TE
authors.lastname: Cleghorn
mesh_terms: D000337:Aerospace Medicine; D018480:Astronauts; D003359:Cosmic Radiation; D004583:Electrons; D005118:Extraterrestrial Environment; D018478:Extravehicular Activity; D005123:Eye / Q000528:radiation effects; D006413:Hematopoietic System / Q000528:radiation effects*; D006801:Humans; D017785:Photons; D011829:Radiation Dosage; D011834:Radiation Monitoring; D011835:Radiation Protection; D012867:Skin / Q000528:radiation effects; D013026:Space Flight; D019442:Space Suits