MAGNETIC NOISE EFFECT ON MAGNETIC NOISE EFFECT ON THE GRAVITROPIC REACTION THE GRAVITROPIC REACTION OF PLANTS AND AMPLITUDE OF PLANTS AND AMPLITUDE

AND SPECTRUM OF AND SPECTRUM OF MAGNETIC FIELD NOISE MAGNETIC FIELD NOISE GENERATED BY PLANTS GENERATED BY PLANTS DURING THEIR GROTHDURING THEIR GROTH

Sheykina NSheykina N. 1, . 1, Bogatina N. Bogatina N. 221-1-VV. . Karazin Kharkov National University Karazin Kharkov National University 4, 4, Svobody squ., KharkovSvobody squ., Kharkov, 61075, , 61075, UkraineUkraine

EmailEmail::SheykinaSheykina@@ukrukr..netnet22--B. B. VerkinVerkin Institute for Low Temperature Physics Institute for Low Temperature Physics

&Engineering of National academy of sciences of Ukraine&Engineering of National academy of sciences of Ukraine, , 47, Lenin ave.,47, Lenin ave., Kharkov, Kharkov, 61100, 61100, UkraineUkraine

ЕмаЕмаiill: : bogatina@ilt.kharkov.uabogatina@ilt.kharkov.ua

THE BASE AND IDEA OF THE WORKTHE BASE AND IDEA OF THE WORK

It is known for a long time that the MF its It is known for a long time that the MF its fluctuation (magnetic storm for instance) fluctuation (magnetic storm for instance) influences on a lot of alive organisms from influences on a lot of alive organisms from the simplest sea weeds and until human the simplest sea weeds and until human being and animals. being and animals.

But the results obtained under usual Earth But the results obtained under usual Earth conditions are reproduced not well enoughconditions are reproduced not well enough

The first purpose was to obtain well The first purpose was to obtain well reproducible magnetic conditions.reproducible magnetic conditions.

The method used for obtaining The method used for obtaining well reproducible conditionswell reproducible conditions

The shielding of external MF in work The shielding of external MF in work volume and creation in it the artificial volume and creation in it the artificial MF with desired characteristics in it.MF with desired characteristics in it.

1method is the using of μ-metal 1method is the using of μ-metal shieldshield

2 method is the using 2 method is the using superconductive shieldsuperconductive shield

SchemeScheme of experiment with μ-metal of experiment with μ-metal shieldshield

The damping rubber (1) supported the holder of dielectric material (2). The μ-metal shield (3) surrounded the samples (4) that were mounted inside a moist chamber of non-magnetic plastic material (5) and solenoids (8, 9). The magnetic field was measured and controlled by sensor elements (fluxgate magnetometer or SQID), (6) inside a holder (7). The solenoids (8, 9) have a cylindrical shape and comprise the system that generates the static magnetic field (9). Both static and alternating magnetic fields are oriented parallel to the central axis. The enlarged central part of the top view shows the orientation of 4 pairs of roots (4), arranged around the magnetic field sensor (7). The coils of solenoids (8, 9) are the spaces between the circles in the bottom part. The space between the innermost circle is the holder of dielectric material (2).

Scheme of experiment with Scheme of experiment with superconducting shieldsuperconducting shield

1 – volume for liquid nitrogen, 2 – external helium cryostat, 3 – isolating cryostat, 4 - superconducting magnetic shield, 5 – warm volume for work, 6 – the upper cover, 7 – the tube for liquid

helium pouring, 8 – the tube for liquid nitrogen pouring, 9 – nitrogen screens of isolating 3 and external helium cryostats.

The dependence of amplitude of spectral The dependence of amplitude of spectral density of magnetic noise for the system: μ-density of magnetic noise for the system: μ-

metal shieldmetal shield + flux gate magnetometer+ flux gate magnetometer

The artificial magnetic noise The artificial magnetic noise creationcreation

The artificial magnetic noise was The artificial magnetic noise was created by noise generator switched created by noise generator switched on parallel with the generator of used on parallel with the generator of used frequency.frequency.

RESULTSRESULTS

1. In combined MF (f=Ca ion cyclotron 1. In combined MF (f=Ca ion cyclotron frequency) the form of the curve of frequency) the form of the curve of dependence of the GTR of cress and pea dependence of the GTR of cress and pea roots on the ratio Broots on the ratio BACAC/B/BDC DC changes with the changes with the increasing of the magnetic noise increasing of the magnetic noise amplitude.amplitude.

2. When the magnetic noise amplitude 2. When the magnetic noise amplitude value increased 10 nT the form of the value increased 10 nT the form of the dependence approached the predicted by dependence approached the predicted by Lednev. But it changed essentially under Lednev. But it changed essentially under this value. this value.

COMPARISON OF EXPERIMENTAL CURVE COMPARISON OF EXPERIMENTAL CURVE WITH GAUSSIAN, LORENCIAN AND BESSEL WITH GAUSSIAN, LORENCIAN AND BESSEL

AT LOW NOISE LEVELAT LOW NOISE LEVEL less than 1nTless than 1nT

COMPARISON OF EXPERIMENTAL COMPARISON OF EXPERIMENTAL CURVE WITH GAUSSIAN, LORENCIAN CURVE WITH GAUSSIAN, LORENCIAN AND BESSEL AT NOISE LEVEL 12nTAND BESSEL AT NOISE LEVEL 12nT

The dependence of magnetic noise The dependence of magnetic noise spectral density on the frequency for spectral density on the frequency for

different systemsdifferent systems

0 1 2 3 41E-11

1E-10

1E-9

1E-8

1E-7

1E-6

1E-5

A , Тл

/ Г

ц 0 , 5

f , Гц

d2

c2

a2 , b

2

d , d1

c , c1

b1

a1

b

a

SYSTEMSSYSTEMS

1. μ-metal shield1. μ-metal shield + flux gate + flux gate magnetometermagnetometer

2. superconducting shield with warm 2. superconducting shield with warm volume + SQUID magnetometervolume + SQUID magnetometer

3. The systems mentioned above + 3. The systems mentioned above + dry or wet growing seeds.dry or wet growing seeds.

CONCLUSIONSCONCLUSIONS

1. We cannot neglect the effects 1. We cannot neglect the effects caused by magnetic noises of caused by magnetic noises of different nature that are always different nature that are always present in the surrounding.present in the surrounding.

2. Sometimes they may have 2. Sometimes they may have decisive significance.decisive significance.