Registration of neutrons within 2 milliseconds after EAS impact

We register an excess of signals from neutron detectors within a few milliseconds after passage of EAS front in Lodz EAS array. The most probable explanation is that neutrons are produced in EAS hadron interactions with lead block of muon detector. These neutrons diffuse and are thermalized before the detection in the Geiger-Müller counters, the boron counter and other detectors registering time structure of the impulses (10 MHz FADC, 8-bit converters, 32 kB memory). We performed computer simulations of neutron diffusion in the vicinity of the array. We used MCNP program and introduced the detailed geometry of the array and its surroundings. Simulated neutrons started their diffusion in the lead block or in the ground near the detector. The obtained time distributions of slow neutrons are consistent with the registrations in the boron counter. The only problem is the requirement of a great number of neutrons produced at the shower arrival. This "new EAS observable" can be used as inexpensive hadron detector in EAS.