Registration of the KeV and MeV neutron burst associated with thunderstorms or lightning Ashot Chilingaryan and Nikolay Bostanjyan A. Alikhanyan National Laboratory, Armenia

The measurements have been conducted by standard neutron monitor, sensitive to high energy atmospheric neutrons and by moderator and lead free proportional counter.

Table1. Characteristics of an observed neutrons bursts associated with lightnings. Results have been obtained for the peaks (one-minute streams) D/ M /Y (N max – N averg )/18 on output 0.4 µs (m^2/min) (N max - N averg ) /18 on output 1250 µs (m^2/min) Duration of events (min ) Comment s 08/05/ ±1.8%44..9±1.2%2 21/05/09 *83.3 ±1.8%53.7±1.2%9 21/05/ ±1.8%86.7±1.2%9 26/05/ ±1.8%37.1±1.2%2 03/06/0990.3±1.8%58.6±1.2%4 08/07/0963.7±1.8%55.7±1.2%19 09/07/0972.4±1.8%54.4±1.2%4 20/08/09 **49.3±1.8%37.6±1.2%5 20/08/0939.8±1.8%30.9±1.2%10 02/09/ ±1.8%34.5±1.2%6 19/09/0962.7±1.8%45±1.2%5 02/11/0949.7±1.8%34.5±1.2%1 19/09/09 NA 430± 5% 21 σ-8Bare tube 26/08/10 NA 719 ± 1.8% 47σ14.7± σ2

Values of the excess neutrons associated with a lightning are presented. The black columns by Aragats neutron monitor, the red column by Nor Amberd NM. Both devices are sensitive to MeV neutrons. The green column by “bare” tube (low-energy neutrons) In one case (red column) the excess neutrons ten times more others (black). They are neutrons MeV energies. They are much more of the neutrons of low energy. There can be such case?

On output 0.4mcs observed huge increase of the count rate of neutrons at 8:03 UT associated with lightning, but on 1250 mcs there is no increase of the count of neutrons

On 1250 mcs there is no increase of the count of neutrons at 8:03UT, but at 9:25, 10:20, 10 34, 10:40 and 11:04 increase of the neutrons are observed as during 0.4mcs

The neutron bursts registered on NM, have duration from one till 19 minutes that can mean neutrons are born not in the processes of a lightning, but in electric fields of thunderstorms

The high- energy neutrons (black points), do not show increase in the time when count rate of the low -energy neutrons sharply increases The number the excess neutrons in peak equal 428n/min. N(σ) =21

А burst of neutrons coincided with a lightning.

Summary Our researches have shown, that during a thunderstorms neutrons from KeV to MeV energies are born Our researches have shown, that excess neutrons can be born in electric fields of thunderclouds and also during lightnings