Anomalous time structure of extensive air shower particle flows in the knee region of primary cosmic ray spectrum

Abstract

We observe the new phenomenon of anomalous prolonged time distributions of neutron intensity using the 18NM64-type neutron monitor operating together with the shower installation of the Tian-Shan mountain cosmic ray station. We observe anomalous events in the core region of extensive air showers (EAS) with the size Ne > 106. The threshold of their generation coincides with the ‘knee’ in the energy spectrum of primary cosmic rays (about 3 × 1015 eV). The prolonged neutron events are accompanied by the flows of EAS electrons and γ-quanta having time distributions similar to those of the neutrons. The discovered phenomenon may be a reason to make a principal change in the usual procedure of EAS exploration.