The Neutron ‘Thunder’ Accompanying Large Extensive Air Showers

The bulk of neutrons which appear with long delays in neutron monitors near to the EAS core (‘neutron thunder’) are produced by high energy EAS hadrons hitting the monitors. This conclusion raises an important problem of the interaction of EAS with the ground, the material of the detectors and their environment. Such interactions can give an additional contribution to the signal in the EAS detectors at km distances from the large EAS core a few μs behind the EAS front.