1. Overview on cosmic radiation at aircraft altitudes Marcin Latocha, Peter Beck, Sofia Rollet, Michael Wind, Andrea Zechner AIT – Austrian Institute of Technology Marcin Latocha | Health & Environment I Nano Systems

2. Outline  Introduction  Galactic Cosmic Radiation  In-flight measurements  Special measurements (CAATER campaign)  Computational Codes  Comparison between codes  AVIDOS as dosimetry service  AVIDOS-WEB for public use  Solar Particle Events  Measurements  Simulations

3. Introduction  Council Directive 96/29/EURATOM, Article 42 “Protection of aircrew”  “Each Member State shall make arrangements for undertakings operating aircraft to take account of exposure to cosmic radiation of air crew who are liable to be subject to exposure to more than 1 mSv per year. […]”  Measures to take Assess the exposure Take into account exposure while planning schedules Inform workers about health risks Special protection during pregnancy and breastfeeding  Civil aviation organizations  Joint Aviation Authorities, JAR-OPS 1, Commercial Air Transport

4. Introduction  European Radiation Dosimetry Group, Work Group 5 on Aviation Dosimetry  26 research institutes (plus external contributors)  Versatile instrumentation and methods  Coordination of European research Measurements Calculation codes  Final Report Lindborg, L., et al. (eds), Cosmic radiation exposure of aircraft crew - Compilation of measured and calculated data, European Commission, Radiation Protection Issue No. 140, (ISBN 92-894-8448-9) (2004)

5. Aircrew In-flight Radiation Exposure Database L. Lindborg et. al. (eds.) Cosmic Radiation Exposure of Aircraft Crew – Compilation of measured and calculated data European Commission, Radiation Protection Issue No. 140, (ISBN 92-894-8448-9), 2004.

6. CAATER - special flight campaign Measuring time: At least 2h at fixed position Vertical cut-off rigidity: r c = 1.8 GV (Aalborg) r c = 6.4 GV (Rome) Altitude: FL 400 (12.2 km) FL 320 (9.8 km) Aalborg (57N, 10E) r c =1.8 GV Rome (42N, 12E) r c = 6.4 GV

7. CAATER - Flight profiles Rome; r c = 6.4 GV FL 400 (12.2 km)FL 320 (9.8 km)

8. CAATER - Measured spectra Absorbed dose distribution Absorbed dose distribution folded in ICRP-60 quality factor Q

9. EURADOS WG5 Codes Comparison  Codes:  AVIDOS  EPCARD  FDOScalc  FREE  PCAIRE  PLANETOCOSMICS  QARM  SIEVERT J. F. Bottollier-Depois et. al. Comparison of codes assessing galactic cosmic radiation exposure of aircraft crew Radiat Prot Dosimetry, October 2009; 136: 317 - 323

10. Codes Comparison J. F. Bottollier-Depois et. al. Comparison of codes assessing galactic cosmic radiation exposure of aircraft crew Radiat Prot Dosimetry, October 2009; 136: 317 - 323 Route effective dose relative to the median

11. AVIDOS  AVIDOS is a computer code allowing calculations of dose assessment of aircraft crew exposure due to cosmic radiation. FLUKAsimulations Fitting functions AVIDOS

12. Monte Carlo code FLUKA  Transport of  electromagnetic particles  hadronic particles  heavy ions  Energy: 20 TeV to …  10keV (all particles)  thermal neutrons (~ 0,1 eV)  1 keV (ph, e - )  Fluence spectra and energy deposition http://www.fluka.org

13. AVIDOS - FLUKA simulations  3D spherical Earth  Height-density profile of the atmosphere geometry spectrum simulations conversion  Updated proton input primary spetrum  Modulation due to solar activity  FLUKA version 2005  Fluence energy spectra  Fluence-to-dose conversion coefficients  Results in terms of dH*(10)/dt, dE/dt In atmosphere, for many different conditions (geographic location, solar activity, altitude)

14. AVIDOS – FLUKA simulations, comparison with measurements CAATER flight Aalborg; FL 400; r c = 1.8 GV CAATER flight Rome; FL 400; r c = 6.4 GV

15. AVIDOS - Fitting functions  Based on FLUKA simulations  Parameters  Barometric altitude, h Atmospheric models  Solar deceleration potential, Φ Sun’s magnetic field polarity CLIMAX neutron monitor count rates  Vertical cut-off rigidity, r c World grid data for 1990 epoch  Set of fitting funtions for selected parameters range

16. AVIDOS - Accreditation  Accredited by Austrian office for accreditation  Input data  Altitude (FL)  Longitude (decimal degree)  Latitude (decimal degree)  UTC (dd/MM/yyyy hh:mm)  Plausibility check  Results  Date/Time (dd/MM/yyyy hh:mm)  Flight duration (minutes)  Ambient dose equivalent, (µSv)  Effective dose, (µSv)  Can be used as a dosimetry service

17. AVIDOS-WEB for public use  Free access for public http://avidos.healthphysics.athttp://avidos.healthphysics.at  Simplified version  Great Circle route  Constant altitude  Estimated flight time  Java web application Internet Webbrowser Server

19. AVIDOS - Summary  AVIDOS code  is based on FLUKA simulations  is accreditted by the Austrian office for accreditation  can be used as a dosimetry service  AVIDOS-WEB is open for public usage  AVIDOS maintenance requires updates  with neutron monitor count rates (CLIMAX)  with Sun’s magnetic field polarity

20. Solar Particle Events  Lead to greatly enhanced radiation in atmosphere  SPE are very hard to predict  Difficult to calculate retrospectively  Not investigated by EURADOS Work Group 5  Only several measurements available  First models are available

21. Solar Particle Events - Halloween Storms on Oct / Nov 2003

23. Solar Particle Events – SOLARDOS project  Existing codes: QARM, SiGLE, PLANETOCOSMICS  SOLARDOS project  PLANETOCOSMICS – Geant4 application  Input proton spectra  Height-density atmospheric profile  Vertical cut-off rigidity  Particle fluence rates  Conversion to dose

24. Solar Particle Events – SOLARDOS project  Proton spectra at the top of atmosphere  neutron monitor data  on-board measurements  space data C. Dyer et. al. Calculations and observations of solar particle enhancements to the radiation environment at aircraft altitudes Adv. Space Res., Vol. 32, 81-93 (2003) S. N. Clucas et al. The radiation in the atmosphere during major solar particle events Adv. Space Res., Vol. 36, pp. 1657-1664 (2005)

25. Solar Particle Events – SOLARDOS project  SPE on 29 th September 1989, at 10.86 km of altitude

26. Solar Particle Events – SOLARDOS project  SPE on 19 th October 1989, at 10.86 km of altitude

27. Solar Particle Events – Summary  At present state different codes can give very different results  Further research is needed for a comprehensive understanding  An activity within EURADOS Work Group 11  To improve models for dose assessment  Validate with experimental data  Further developments can be supported by  Satellite measurements  On-board aircraft measurements  Neutron monitor stations records

28. Thank you! Marcin Latocha | Health & Environment I Nano Systems