Estimating ground-level neutron-flux enhancements in the extreme cosmic-ray events of the next 100, 1000 and 10 000 years

摘要

Estimates are proposed of the enhancement in neutron flux which may be experienced at ground level in cosmic-ray events of extreme magnitude over the next century, millennium and ten millennia. The estimates are based on a points-over-threshold analysis of hourly neutron counts measured over the last decades by nine neutron-monitor stations located in Europe, North America and Antarctica. The present results are in good agreement with recent studies of extreme solar events based on the direct observation of flares and the abundance of cosmogenic nuclides in terrestrial and lunar archives. (C) 2015 Elsevier Ltd. All rights reserved.