title: Implications for space radiation environment models from CREAM & CREDO measurements over half a solar cycle.
abstract: Flight data obtained between 1990 and 1997 from the Cosmic Radiation Environment Monitors CREAM & CREDO carried on UoSAT-3, Space Shuttle, STRV-1a (Space Technology Research Vehicle) and APEX (Advanced Photovoltaic and Electronics Experiment Spacecraft) provide coverage over half a solar cycle. The modulation of cosmic rays and evolution of the South Atlantic Anomaly are observed, the former comprising a factor of three increase at high latitudes and the latter a general increase accompanied by a north-westward drift. Comparison of particle fluxes and linear energy transfer (LET) spectra is made with improved environment & radiation transport calculations which account for shield distributions and secondary particles. While there is an encouraging convergence between predictions and observations, significant improvements are still required, particularly in the treatment of locally produced secondary particles. Solar-particle events during this time period have LET spectra significantly below the October 1989 event which has been proposed as a worst case model.
authors.affiliation: Space Department, DERA Farnborough, UK.
authors.forename: C S
authors.initials: CS
authors.lastname: Dyer
authors.forename: P R
authors.initials: PR
authors.lastname: Truscott
authors.forename: C L
authors.initials: CL
authors.lastname: Peerless
authors.forename: C J
authors.initials: CJ
authors.lastname: Watson
authors.forename: H E
authors.initials: HE
authors.lastname: Evans
authors.forename: P
authors.initials: P
authors.lastname: Knight
authors.forename: M
authors.initials: M
authors.lastname: Cosby
authors.forename: C
authors.initials: C
authors.lastname: Underwood
authors.forename: T
authors.initials: T
authors.lastname: Cousins
authors.forename: R
authors.initials: R
authors.lastname: Noulty
authors.forename: C
authors.initials: C
authors.lastname: Maag
mesh_terms: D001267:Atlantic Ocean; D003359:Cosmic Radiation; D018499:Linear Energy Transfer; D008962:Models, Theoretical; D009502:Neutrons; D011522:Protons; D011829:Radiation Dosage; D011834:Radiation Monitoring / Q000295:instrumentation*; D019445:Solar Activity; D013020:South America; D018531:Spacecraft / Q000295:instrumentation; D013057:Spectrum Analysis
chemical_list: D011522:Protons