Logo der Physikalisch-Technischen Bundesanstalt

Secondary neutrons from cosmic radiation - impact of environmental parameters

Kolloquium der Abteilung 6

Since ICRP Publication 60 was published in 1991, exposures to natural sources of ionizing radiation are considered as part of occupational exposure. Consequently, radiation exposure of air crew to cosmic radiation became of interest in radiological protection. This prompted members of the Institute of Radiation Protection at the Helmholtz Center Munich, Germany, to develop the European Program Package for the Calculation of Air Route Doses (EPCARD). The development was backed by measurements of secondary neutrons from cosmic radiation. Specifically, energy spectra of secondary neutrons from cosmic radiation have been continuously measured by means of Bonner Sphere Spectrometers, on the Zugspitze mountain, Germany (altitude: 2650 m; latitude: 47.4° N; cutoff rigidity: 4.4 GV) since 2005, and on Spitsbergen (sea level; latitude: 79 °N; cutoff: ~0 GV) since 2007, respectively. At both sites it has been noted for the first time that these neutron spectra and neutron dose rates change with season in a systematic way. More recently, systematic Monte Carlo simulations have been carried out to investigate those changes in more detail. The investigations described in this presentation help to understand the presence of any changes of secondary neutrons from cosmic radiation at the intersection between lithosphere and atmosphere.



(ohne PIN)