| Zugriffsnummer | 11543 |
| Dokumenttyp | Bericht |
| Sprache | Englisch |
| Titel | ACREM - air crew radiation exposure monitoring. [Part 2:] Summary of results from calibrations and TEPC measurements |
| Autor(in); Institution |
Schrewe, Ulrich; 6.31, Ionendosimetrie und Beschleunigerbetrieb, PTB-Braunschweig
|
| Quelle/Jahr | (1999), 35 S. |
| Schriftenreihe | PTB-Laborbericht PTB-6.31-99-2 |
| Herausgeber(in) |
Physikalisch-Technische Bundesanstalt
|
| Berichtsnummer | PTB-6.31-99-2 |
| Verlag | Braunschweig [u.a.]: PTB |
| Freie Schlagworte | dosimetry in flight altitudes |
| Zusammenfassung | Based on the 1990 Recommendations of the International Commission on Radiological Protection (ICRP), a European Directive commits the European Union (EU) member states to revise their national radiation protection laws by May 2000 such that the exposure of air crews to the increased cosmic radiation prevailing at aviation flight altitudes will be treated as occupational risk. A consequence will be that employers must assess the aircrew exposure. The complex composition of the radiation field in aviation altitudes, i. e. the great number of different particles and the wide range of particle energies, requires that instruments and calibration methods must be specifically fitted to the field properties. The ACREM (Air Crew Radiation Exposure Monitoring) research project intends to develop and to test practically methods for aircraft dose equivalent determination. The project includes a series of in-flight measurements on Lufthansa Cargo aircraft. Various monitors were used to measure different radiation field components and to investigate the spatial doserate distribution and the spatial radiation field composition. The monitors were rem counters for neutrons, a scintillator and an ionization chamber for the ionizing components. The present report brtiefly describes the underlying calibration principles, the calibration procedures applied and various response investigations. The sum of the dose equivalent readings of a neutron rem counter (NMX) modified with a lead inlet to improve the fluence response at high energies and an ionization chamber (IC) was found to be a fair approximation of the total dose equivalent. The measurements performed with a tissue-equivalent proportional counter (TEPC) in flight altitudes determined the field calibration factor for the sum of NMX and IC, (dH/dt)TEPC/(dH/dt)NMX+IC = 0,96, with a statistical uncertainty of 2% and a total uncertainty of 10%. By surrounding the TEPC with an active shielding detector and applying coincidence techniques it was possible to separate dose equivalent fractions of charged and uncharged particles in the cosmic radiation. Report |
| Rechteinformation | 1999, Physikalisch-Technische Bundesanstalt |