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 (Nmax – Naverg )/18

on output 0.4 µs

(m^2/min)

(Nmax - Naverg ) /18

on output 1250 µs

(m^2/min)

Duration of events

(min)

Comments

08/05/09 72..3 ±1.8% 44..9±1.2% 2

21/05/09 * 83.3 ±1.8% 53.7±1.2% 9

21/05/09 93.7 ±1.8% 86.7±1.2% 9

26/05/09 51..9 ±1.8% 37.1±1.2% 2

03/06/09 90.3±1.8% 58.6±1.2% 4

08/07/09 63.7±1.8% 55.7±1.2% 19

09/07/09 72.4±1.8% 54.4±1.2% 4

20/08/09 ** 49.3±1.8% 37.6±1.2% 5

20/08/09 39.8±1.8% 30.9±1.2% 10

02/09/09 48..9±1.8% 34.5±1.2% 6

19/09/09 62.7±1.8% 45±1.2% 5

02/11/09 49.7±1.8% 34.5±1.2% 1

19/09/09 NA 430± 5% 21 σ - 8 Bare tube

26/08/10 NA 719 ± 1.8% 47σ 14.7±1.2 1.7 σ 2

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?

050

100150200250300350400450500550600650700750

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

Number of events

Nu

mb

er o

f ex

cess

neu

tro

ns

(m^

2/m

in

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

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

26 August, 2010

-30369

121518212427303336394245

7:30 8:00 8:30 9:00 9:30 10:00 10:30 11:00 11:30 12:00

UT

Rel

ativ

e in

crea

se o

f n

eutr

ons

(%)

0

5

10

15

20

25

30

35

Sig

nal

fro

m p

osit

iv

Inte

rclo

ud

Lig

htn

ings

By NANM By Byurakan antenna

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

26 August, 2010

-3

-1.5

0

1.5

3

4.5

6

7.5

9

7:30 8:00 8:30 9:00 9:30 10:00 10:30 11:00 11:30

UT

Rel

ativ

e co

un

t ra

te o

f n

eutr

ons

(%)

0

5

10

15

20

25

30

Sig

nal

s fr

om p

ozit

iv

ligh

nin

gs (

clou

d-

grou

nd

)

by NANM 1250mcs by Byrakan antena

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

0123456789

1011121314151617181920

1 2 3 4 5 6 7 8 9 10 11 12 13

Number of events

Du

rati

on

of

even

ts

(min

)

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

19 September, 2009

-2.5

0

2.5

5

7.5

10

12.5

15

8:00 8:30 9:00 9:30

UT

Rel

ati

ve

incr

ease

of

hig

h-e

ner

gy

neu

tro

ns

-20

5

30

55

80

105

Rel

ati

ve

incr

ease

of

low

-en

erg

y n

eutr

on

s

By NANM By Bare tube

А burst of neutrons coincided with a lightning.

19 September, 2009

-150

153045607590

105

8:00 8:15 8:30 8:45 9:00 9:15 9:30 9:45

UT

Rel

ati

ve

incr

ease

of

neu

tron

s (%

)

1400

1500

1600

1700

1800

1900

2000

Fre

qu

ency

By bare tube (Nor Amberd) By the Aragats antenna

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