Servizio Comunitario di Informazione in materia di Ricerca e Sviluppo - CORDIS


DOSMAX Sintesi della relazione

Project ID: FIGM-CT-2000-00068
Finanziato nell'ambito di: FP5-EAECTP C
Paese: Austria

Calculation results of numerical program codes (cosmic radiation and solar events)

Simulation results of the radiation exposure caused by the galactic cosmic radiation have been compared successfully with onboard instruments. The calculation was provided by the high-energy particle transport code FLUKA, the program package EPCARD version 3.2 and CARI-6. Experimental results of several active and passive dosimeters compared well for a wide range of aircraft positions and solar conditions within 30% uncertainty on average, for a confidence level of two standard deviations.

The calculation results for solar energetic particles (SEPs) show that the radiation fields in the atmosphere depend significantly on the form of SEP primary spectra.

Two important conclusions can be drawn:
-The uncertainties of the primary spectra affect fluence rates much more than spectral shapes of secondary particles generated inside the atmosphere. This means that experimental devices which have been established in experiments studying the neutron component of the radiation induced by galactic cosmic rays may be used without serious problems of calibration in situations of higher radiation levels during a sporadic SEP event.

-This situation can be different if particles of the electromagnetic cascade contribute significantly to the instrumental readout. The fluence rate of this component depends sensitively on the hardness of the SEP-spectrum and differs significantly for SEP-induced radiation and radiation induced by galactic cosmic rays.

The numerical simulation of microdosimetric spectra measured by a tissue equivalent proportional counter (TEPC) is successfully demonstrated using the simulation code FLUKA. Comparison of measurements and simulation results in standard radiation conditions show good agreement. For ambient dose equivalent measurement at aircraft location close to the fuel tank the experimental data show a 25% dose reduction for high LET compared to simulation results in free air.

Calculation results of numerical program codes will be used for dose assessment in future aircrew dosimetry. The evaluated results of the program codes will provide methods and tools for practical dosimetry.

The calculation of Solar Energetic Events needs still further research and evaluation by experimental observations due to their complex physics.

The results will provide a reliable basis to inform the public and aircraft crew about the radiation effect in air travelling.

Informazioni correlate

Reported by

ARC Seibersdorf research
Heath Physics Division
2444 Seibersdorf