Anatoliy Toropov
Institute of Cosmophysical Research and Aeronomy
Russia
Title: Observation of neutron burst associated with cloud-to-ground lightning discharges
Biography
Biography: Anatoliy Toropov
Abstract
The made at the Institute for Cosmophysical Research and Aeronomy of an instrument system for the synchronous recording of variations in the neutron flux, the atmosphere electric field strength and the electromagnetic radio emission during lightning discharges is reported. Neutrons were detected at Yakutsk (altitude 94m, latitude 61°59.362′ N, longitude 129°41.874′ E) by a low-energy cosmic-ray SNM-15 lead- covered neutron counter and lead-free neutron counter with 10-μs resolution are obtained during short-range lightning events in the vicinity of Yakutsk. In the immediate vicinity of the neutron detectors the electric field-mill was installed to register the electric field and its variations during thunderstorms. The electric field-mill was calibrated in an artificial electric field and has a measurement range of +/-50 kV/m. A linear antenna is mounted in the vicinity of neuron detectors to sense the short-term electric field variations associated with a lightning discharge. It was found that the neutron bursts are observed in the negative lightning discharge only. It was established that all the neutron flux bursts were observed during the thunderstorms with the only type of electric structure of the thundercloud having a compact positive charge at the bottom. We discuss the possibility of generation of neutrons in the lower part (the point of impact into the ground) lightning discharge.