Nd-Fe-B magnets under electron irradiation with the energy of 23 MeV
Four Nd-Fe-B magnets underwent irradiation under 23 MeV electron beam. Nd-Fe-B magnets were magnetized to the technical saturation in the magnetic field of 3.5 T before electron treatment. Two Nd-Fe-B samples (1 and 2) were exposed to the direct electron beam with the energy of 23 MeV. Sample 2 was...
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| Zitieren: | Nd-Fe-B magnets under electron irradiation with the energy of 23 MeV / V.A. Bovda, А.М. Bovda, I.S. Guk, A.N. Dovbnya, V.N. Lyashchenko, A.O. Mytsykov, L.V. Onishchenko, S.S. Каndybei, О.А. Repikhov // Problems of atomic science and tecnology. — 2020. — № 3. — С. 23-27. — Бібліогр.: 12 назв. — англ. |
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irk-123456789-1944932023-11-26T20:52:33Z Nd-Fe-B magnets under electron irradiation with the energy of 23 MeV Bovda, V.A. Bovda, А.М. Guk, I.S. Dovbnya, A.N. Lyashchenko, V.N. Mytsykov, A.O. Onishchenko, L.V. Каndybei, S.S. Repikhov, О.А. Theory and technology of particle acceleration Four Nd-Fe-B magnets underwent irradiation under 23 MeV electron beam. Nd-Fe-B magnets were magnetized to the technical saturation in the magnetic field of 3.5 T before electron treatment. Two Nd-Fe-B samples (1 and 2) were exposed to the direct electron beam with the energy of 23 MeV. Sample 2 was shielded by tungsten converter. The thickness of the tungsten converter was 4.72 mm. The absorbed dose for the samples was 16 GRad. Sample 3 was subjected to bremsstrahlung of electron irradiation with the energy of 23 MeV. Sample 4 was used as a reference sample for calibration and control measurements. While magnetic flux of sample under direct electron beam of 23 MeV was changed significantly, sample 2 showed the change of magnetic flux to a less degree. Magnetic performance of sample 3 corresponded closely to the initial state. Були проведені експериментальні дослідження поля чотирьох зразків магніту з Nd-Fe-B-сплаву, попередньо намагнічених в імпульсному магнітному полі 3,5 Тл. Зразки № 1 і 2 піддавалися прямій дії електронним пучком з енергією 23 МеВ. Перед зразком № 2 впритул містився конвертор з вольфраму товщиною 4,72 мм. Поглинена доза для зразків складала 16 Град. Зразок № 3 піддавався впливові гальмівного випромінювання електронним пучком з енергією 23 МеВ. Зразок № 4 не опромінювався і служив опорним еталоном для калібрування точності методу і контрольних вимірів. Спостерігається істотна зміна магнітного поля зразка № 1, що піддавався прямій дії електронним пучком з енергією 23 МеВ. У меншій мері ця зміна спостерігалася для зразка № 2. Поле навколо зразка № 3 практично не змінилося. Были проведены экспериментальные исследования поля четырёх образцов магнита из Nd-Fe-B-сплава, предварительно намагниченных в импульсном магнитном поле 3,5 Тл. Образцы № 1 и 2 подвергались прямому воздействию электронным пучком с энергией 23 МэВ. Перед образцом № 2 вплотную помещался конвертор из вольфрама толщиной 4,72 мм. Поглощённая доза для образцов составляла 16 Град. Образец № 3 подвергался воздействию тормозным излучением электронного пучка с энергией 23 МэВ. Образец № 4 не облучался и служил опорным эталоном для калибровки точности метода и контрольных измерений. Наблюдается существенное изменение магнитного поля образца № 1, подвергавшегося прямому воздействию электронным пучком с энергией 23 МэВ. В меньшей мере это изменение наблюдалось для образца № 2. Поле вокруг образца № 3 практически не изменилось. 2020 Article Nd-Fe-B magnets under electron irradiation with the energy of 23 MeV / V.A. Bovda, А.М. Bovda, I.S. Guk, A.N. Dovbnya, V.N. Lyashchenko, A.O. Mytsykov, L.V. Onishchenko, S.S. Каndybei, О.А. Repikhov // Problems of atomic science and tecnology. — 2020. — № 3. — С. 23-27. — Бібліогр.: 12 назв. — англ. 1562-6016 PACS: 29.30.Kv http://dspace.nbuv.gov.ua/handle/123456789/194493 en Вопросы атомной науки и техники Національний науковий центр «Харківський фізико-технічний інститут» НАН України |
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DSpace DC |
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Theory and technology of particle acceleration Theory and technology of particle acceleration |
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Theory and technology of particle acceleration Theory and technology of particle acceleration Bovda, V.A. Bovda, А.М. Guk, I.S. Dovbnya, A.N. Lyashchenko, V.N. Mytsykov, A.O. Onishchenko, L.V. Каndybei, S.S. Repikhov, О.А. Nd-Fe-B magnets under electron irradiation with the energy of 23 MeV Вопросы атомной науки и техники |
| description |
Four Nd-Fe-B magnets underwent irradiation under 23 MeV electron beam. Nd-Fe-B magnets were magnetized to the technical saturation in the magnetic field of 3.5 T before electron treatment. Two Nd-Fe-B samples (1 and 2) were exposed to the direct electron beam with the energy of 23 MeV. Sample 2 was shielded by tungsten converter. The thickness of the tungsten converter was 4.72 mm. The absorbed dose for the samples was 16 GRad. Sample 3 was subjected to bremsstrahlung of electron irradiation with the energy of 23 MeV. Sample 4 was used as a reference sample for calibration and control measurements. While magnetic flux of sample under direct electron beam of 23 MeV was changed significantly, sample 2 showed the change of magnetic flux to a less degree. Magnetic performance of sample 3 corresponded closely to the initial state. |
| format |
Article |
| author |
Bovda, V.A. Bovda, А.М. Guk, I.S. Dovbnya, A.N. Lyashchenko, V.N. Mytsykov, A.O. Onishchenko, L.V. Каndybei, S.S. Repikhov, О.А. |
| author_facet |
Bovda, V.A. Bovda, А.М. Guk, I.S. Dovbnya, A.N. Lyashchenko, V.N. Mytsykov, A.O. Onishchenko, L.V. Каndybei, S.S. Repikhov, О.А. |
| author_sort |
Bovda, V.A. |
| title |
Nd-Fe-B magnets under electron irradiation with the energy of 23 MeV |
| title_short |
Nd-Fe-B magnets under electron irradiation with the energy of 23 MeV |
| title_full |
Nd-Fe-B magnets under electron irradiation with the energy of 23 MeV |
| title_fullStr |
Nd-Fe-B magnets under electron irradiation with the energy of 23 MeV |
| title_full_unstemmed |
Nd-Fe-B magnets under electron irradiation with the energy of 23 MeV |
| title_sort |
nd-fe-b magnets under electron irradiation with the energy of 23 mev |
| publisher |
Національний науковий центр «Харківський фізико-технічний інститут» НАН України |
| publishDate |
2020 |
| topic_facet |
Theory and technology of particle acceleration |
| url |
http://dspace.nbuv.gov.ua/handle/123456789/194493 |
| citation_txt |
Nd-Fe-B magnets under electron irradiation with the energy of 23 MeV / V.A. Bovda, А.М. Bovda, I.S. Guk, A.N. Dovbnya, V.N. Lyashchenko, A.O. Mytsykov, L.V. Onishchenko, S.S. Каndybei, О.А. Repikhov // Problems of atomic science and tecnology. — 2020. — № 3. — С. 23-27. — Бібліогр.: 12 назв. — англ. |
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Вопросы атомной науки и техники |
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ISSN 1562-6016. ВАНТ. 2020. №3(127) 23
Nd-Fe-B MAGNETS UNDER ELECTRON IRRADIATION
WITH THE ENERGY OF 23 MeV
V.A. Bovda, А.М. Bovda, I.S. Guk, A.N. Dovbnya, V.N. Lyashchenko, A.O. Mytsykov,
L.V. Onishchenko, S.S. Каndybei, О.А. Repikhov
National Science Center “Kharkov Institute of Physics and Technology”, Kharkiv, Ukraine
E-mail: guk@kipt.kharkov.ua
Four Nd-Fe-B magnets underwent irradiation under 23 MeV electron beam. Nd-Fe-B magnets were magnetized
to the technical saturation in the magnetic field of 3.5 T before electron treatment. Two Nd-Fe-B samples (1 and 2)
were exposed to the direct electron beam with the energy of 23 MeV. Sample 2 was shielded by tungsten converter.
The thickness of the tungsten converter was 4.72 mm. The absorbed dose for the samples was 16 GRad. Sample 3
was subjected to bremsstrahlung of electron irradiation with the energy of 23 MeV. Sample 4 was used as a refer-
ence sample for calibration and control measurements. While magnetic flux of sample under direct electron beam of
23 MeV was changed significantly, sample 2 showed the change of magnetic flux to a less degree. Magnetic per-
formance of sample 3 corresponded closely to the initial state.
PACS: 29.30.Kv
INTRODUCTION
High performance rare-earth permanent magnets
have wide application in the various magnetic systems
of electron accelerators. However, potential exposure of
rare-earth permanent magnets to the radiation fields
induces magnetic degradation and damage of magnetic
materials [1]. It was shown that Sm-Co magnets are
preferred choice in some high-temperature applications
due to strong resistance to radiation-induced demagneti-
zation effects [2]. Despite the good magnetic perform-
ance of Sm-Co magnets under 23 MeV [4] in compari-
son with Nd-Fe-B magnets following irradiating at a
twice lower energy of 10 MeV [3, 5], the high radiation
activity of the former greatly hampers their practical use
in the actual compact electron accelerators [4]. High-
temperature grades of Nd-Fe-B magnets are typically
doped with Cobalt, which affects the radiation activity
of magnetic samples also. Moreover, Nd-Fe-B magnets
with identical stoichiometric compositions from differ-
ent producers show various remanence loses [2].
The purpose of this paper is to study the demagneti-
zation behaviour of Nd-Fe-B magnets protected by a
barrier and exposed to an electron beam with the energy
of 23 MeV. We investigate how Tungsten barrier can
keep magnetic performance under irradiation.
1. EXPERIMENTAL DETAILS
Four Nd-Fe-B magnets produced by PLP technology
[6, 7] with dimensions of 304012 mm were used in the
study. The density of the magnets was 7.35…7.4 g/cm3.
All four magnets were covered with a thin coating of
nickel to reduce oxidation of the magnetic material. The
coercitivity, remanence and Curie temperature of these
magnets are Br=1.2 T, Hcj=1190 kA/m, Tc=320C. Each
magnet had a unique identification namely sample 1, 2, 3,
and 4. Samples were magnetized at the field of 3.5 T to
the technical saturation. The temperature of the samples
during irradiation was kept constant at about T=40С by
the cooling system.
Irradiation of sample 1 and sample 2 was performed
at the EPOS linear technological accelerator. The electron
beam of 23 MeV is used for irradiating the magnets [8].
A vertically unfolded electron beam was brought out
horizontally from the accelerator into the air through a
titanium foil [9]. Then, the electron beam was scattered
on the Al foil and reached the surface of the magnets at
the distance of 1.35 m from the accelerator exit. The
orientation of the magnets was chosen to provide elec-
tron irradiation of 3040 mm plane (south pole). The
deviation of electron flux within magnet’s surface was
lower 10%.
W-convertor with the thickness of 4.72 mm was in-
stalled adjacent to sample 2 and exposed to the electron
beam.
Sample 3 was placed outside the electron beam at
the distance of 300 mm from the irradiation area.
Space of irradiation around magnetic samples, di-
mensions 13056020 mm, was filled with the light-
weighted material (density 3.5 g/cm3) yielding a 75%
loss of electron energy. Hence, magnetic samples were
exposed to the γ-ray Bremsstrahlung with an intensity of
50 times more than Bremsstrahlung produced by elec-
trons emerging at the samples.
Samples 1, 2 and 3 were irradiated within 192 hours.
The absorbed dose generated by electrons was 16 GRad
(the fluence for the absorbed dose 1.41017 cm-2).
Sample 4 was not irradiated and used as a reference
sample for calibration and control measurements.
2. RADIATION MEASUREMENTS
After the irradiation, samples were held for 16 days
to become safe for radioactivity measurements.
CANBERRA GC1818 spectrometer equipped with a
high-sensitivity germanium semiconducting detector
was used to record the gamma-ray spectrum of the
magnetic samples. The relative efficiency and 60Co line
energy resolution of the detector are 18% and 1.8 keV
accordingly. CANBERRADSA 1000 digital spectrum
analyzer with in-built high voltage source was used as
the acquisition and analysis system.
The efficiency calibration of the spectrometer was
carried out by standard etalons including 133Ba, 137Cs,
241Am, 22Na, 60Co, and 152Eu. Absolute efficiency curves
were described by Campbell function [10].
Fig. 1 shows the example of the absolute efficiency
versus energy obtained by the etalon source of 152Eu at
the distance of 10 cm from the detector window.
ISSN 1562-6016. ВАНТ. 2020. №3(127) 24
Fig. 1. The absolute efficiency versus energy (etalon
source of 152Eu at the distance of 10 cm from detector
window)
Activity measurements were performed in the low-
background conditions. The low-background conditions
were achieved by passive cylindrical shield combining
Pb layer (~10 cm), Cd layer (5 mm), and Cu layer
(5 mm). Measured γ-spectrums were processed by Win-
Spectrum [11].
Spectrums of samples 1, 2, and 3 after irradiation are
shown in Figs. 2, 3, and 4 correspondingly. The exposi-
tion of measurements was 10 min.
Fig. 2. Induced gamma-activity spectrum of sample 1
(exposition – 10 min). Almost all unmarked peaks
correspond to 147Nd isotope
Fig. 3. Induced gamma-activity spectrum of sample 2
(exposition – 10 min). Almost all unmarked peaks
correspond to 147Nd isotope
Fig. 4. Induced gamma-activity spectrum of sample 3
(exposition – 10 min)
It can be seen that γ-spectrums of sample 1 and 2 are
very similar with a bit smaller activation of sample 2.
The activation of sample 3 was considerably lower. It
was characterized by the lines of the same isotopes as
for samples 1 and 2.
3. MAGNETIC MEASUREMENTS AFTER
IRRADIATION
The normal component of magnetic field intensity
for each of the four Nd-Fe-B magnets was measured
with seven Hall probes supported on the non-magnetic
bar [12]. The magnetic sample was moved across the
bar. The distance between Hall probes was about 6 mm.
The starting point of the sample positioned to the bar
was fixed by the stopper system. The sample was
moved parallel to the surface of the bar. The distance
between sample and bar was 3.05 mm. The step be-
tween points of measurements along the sample's sur-
face was from 2 to 5 mm. The accuracy of the sample
positioning was about 1 micron.
The measurements of magnetic field intensity on the
south pole was performed by 180-degree rotation of the
sample along long axis after Hall probe scanning of
north pole side. The relative error of the normal compo-
nent of magnetic field intensity was about 0.01%.
Integral of the normal component of magnetic field
intensity by scanned area I=∫Bnormds was calculated to
estimate the magnetic field of the samples in arbitrary
units. Repetitive scans and calculated I – parameter for
each magnetic sample showed little variation with the
infinitesimal error of 0.5%.
The area of interpolation was limited by the out-to-
out distance of Hall probes liner and scanning points
along the samples' surface accurately fixed by a coordi-
nate system.
The scanned data of magnetic field intensity for the
south pole of sample 4 before irradiation is shown in
Fig. 5.
The interpolation of scanned sample 4 gives the dis-
tribution of the magnetic field (Fig. 6).
Integrals of normal component of magnetic field in-
tensity by scanned area of un-irradiated samples north
pole) revealed very similar values of I1 = 176.4; I2 =
177.9; I3 = 178.1, and I4 = 175.4. Additionally, the I
ISSN 1562-6016. ВАНТ. 2020. №3(127) 25
parameters of south pole side are in very good agree-
ment with north pole ones within the accuracy limits.
Fig. 5. Scanned data of magnetic field intensity
of sample 4 (south pole)
Fig. 6. The distribution of magnetic field intensity
sample 4 (South pole)
The result obtained by integration and interpolation
of sample 1 following irradiation of a direct electron
beam of 23 MeV revealed dramatic flux loss. Magnetic
field distribution of sample 1 after irradiation is pre-
sented in Fig. 7. I parameter of sample 1 after irradiation
dropped to I1 = 74.69.
Similar behaviour was observed in sample 2 after ir-
radiation (Fig. 8). I parameter of irradiated sample 2
decreased to I2 = 107.37. However, no significant
change in magnetic flux was measured and calculated
for sample 3 following irradiation (Fig. 9). The I pa-
rameter of irradiated sample 3 estimated to be I3 =
176.56.
Fig. 7. The distribution of magnetic field intensity
sample 1 after irradiation
Fig. 8. The distribution of magnetic field intensity
sample 2 after irradiation
Fig. 9. The distribution of magnetic field intensity
sample 3 after irradiation
Similar data for south pole surfaces were measured
within accuracy limits for all samples after irradiation.
4. REPEATED MAGNETIC
MEASUREMENTS
AND REMAGNETIZATION
Repeated magnetic measurements were performed in
3 years and 8 months after irradiation experiments.
According to Figs. 10, 11, and 12, the results of re-
peated magnetic scanning suggest that magnetic field
distribution and I parameter correlate well with previous
measurements.
Fig. 10. The distribution of magnetic field intensity
of the south pole surface of irradiated sample 1
(measurements in 3 year and 8 months)
ISSN 1562-6016. ВАНТ. 2020. №3(127) 26
Fig. 11. The distribution of magnetic field intensity
of the south pole surface of irradiated sample 2
(measurements in 3 year and 8 months)
Fig. 12. The distribution of magnetic field intensity
of the south pole surface of irradiated sample 3
(measurements in 3 year and 8 months)
I parameter of south pole surface of irradiated sam-
ples attributed to I1 = -68.5403; I2 = -95.876; I3 =
-165.099 correspondingly.
The results are shown in Figs. 10, 11, and 12 indi-
cate a slight decrease of parameters in comparison with
Figs. 7, 8, and 9 due to samples shift relatively to Hall
probes positions.
Then, samples 1, 2, and 3 were remagnetized to the
technical saturation in the magnetic field of 3.5 T and
same polarity as before irradiation experiments. As an
example, the distribution of magnetic field intensity of
sample 1 following irradiating by a 23 MeV electron
beam and remagnetization is depicted in Fig. 13.
Fig. 13. The distribution of magnetic field intensity
of sample 1 following irradiating by a 23 MeV electron
beam and remagnetization
The same recovery of magnetic performance was
observed for irradiated samples 2 and 3 after remag-
netization. I parameters for irradiated and remagnet-
ized samples (south pole) were about I1 = -167.364;
I2 = -166.862; I3 = -167.278 correspondingly. Fig. 14
depicts an example of a Y-plane scan of irradiated sam-
ple 2 after remagnetization. The measurement was per-
formed by probe 4.
Fig. 14. Y-plane scan of irradiated sample 2 after
remagnetization
It was also revealed that Y-plane scans of irradiated
sample 1 and 3 after remagnetization had practically the
same patterns as sample 2.
SUMMARY
The effects of irradiation with 23 MeV on magnetic
field intensity and spatial distribution of Nd-Fe-B mag-
nets were studied.
It was revealed that the magnetic performance of
magnets exposed to Bremsstrahlung produced by elec-
tron beam did not undergo noticeable changes.
Despite irradiating conditions as direct electron
beam, bremsstrahlung and W-converted barrier, all Nd-
Fe-B magnets showed full restoration of magnetic prop-
erties after remagnetization.
REFERENCES
1. N. Simos, et al. Demagnetization of Nd2Fe14B,
Pr2Fe14B, and Sm2Co17 Permanent Magnets in Spal-
lation Irradiation Fields // IEEE Transactions on
Magnetics. 2018, v. 54, p. 1-10.
2. H. Luna, X. Maruyama, N. Colella, J. Hobbs,
R. Hornady, B. Kulke, and J. Palomar.
Bremsstrahlung Radiation Effects in Rare Earth
Permanent Magnets // 10-th International FEL Con-
ference, Jerusalem, Israel, Aug. 29 - Sept. 2, 1988,
preprint UCRL-100167.
3. V.A. Bovda et al. Magnetic field losses in Nd-Fe-B
magnets under 10 MeV electron irradiation // Prob-
lems of Atomic Science and Technology. Series “Nu-
clear Physics Investigations”. 2017, № 3, p. 90-94.
4. А.М. Bovda et al. Magnetic properties of Sm2Co17
magnets under 10 MeV electron beam // Problems of
Atomic Science and Technology. Series “Nuclear
Physics Investigations”. 2017, № 6, p. 162-166.
5. V.A. Bovda et al. Magnetic properties of Nd-Fe-B
magnets under electron beam irradiation with the
energy 23 MeV // Problems of Atomic Science and
Technology. Series “Nuclear Physics Investiga-
tions”. 2018, № 3, p. 163-167.
6. Yasuhiro Une and Masato Sagawa. Enhancement of
Coercivity of Nd-Fe-B Sintered Magnets by Grain
Size Reduction // J. Japan Inst. Metals. 2012, v. 76,
№ 1, p. 12-16.
7. V.A. Bovda, A.M. Bovda, I.S. Guk, A.N. Dovbnya,
S.G. Kononenko, V.N. Lyashchenko, A.O. Myt-
sykov, L.V. Onischenko. Dipole magnet with a per-
manent magnetic field for technological electron ac-
ISSN 1562-6016. ВАНТ. 2020. №3(127) 27
celerator // Proceedings Rare-Earth and Future
Permanent Magnets and their Applications. Darm-
stadt, Germany, 28.8.-1.9.2016, p. 481-488.
8. M.I. Ayzatsky, V.N. Boriskin, A.M. Dovbnya,
V.A. Kushnir, V.A. Popenko, V.A. Shendrik,
Yu.D. Tur, A.I. Zykov. The NSC KIPT electron li-
nacs - R&D // Problems of Atomic Science and
Technology. Series “Nuclear Physics Investiga-
tions”. 2003, № 2, p. 19-25.
9. A. Dovbnya, I. Guk, S. Kononenko, G. Kovalev,
A.Mytsykov. The second output beam channel at ac-
celerator “EPOS” // Problems of Atomic Science and
Technology. Series “Nuclear Physics Investiga-
tions”. 2014, № 3, p. 8-12.
10. L.A. McNelles, J.L. Campbell. Absolute efficiency
calibration of coaxial Ge(Li) detectors for the energy
range 160…1330 keV // Nuclear Instruments and
Methods. 1973, v. 109, Issue 2, p. 241-251.
11. I.N. Vishnevsky, V.A. Zheltonozhsky, A.G. Zelinsky,
et al. Atomic-nuclear effects in the process of inter-
nal conversion of gamma-rays // Scientific Papers of
the Institute for Nuclear Research. 1999, p. 60-64.
12. I.S. Guk, A.N. Dovbnya, S.G. Kononenko,
V.N. Lyashchenko, A.Yu. Mytsykov, V.P. Romas’ko,
A.S. Tarasenko, V.N. Shcherbinin. Dipole magnet of
the energy filter for the accelerator “EPOS” // Prob-
lems of Atomic Science and Technology. Series “Nu-
clear Physics Investigations”. 2012, № 3, p. 67-69.
Article received 29.01.2020
ИЗМЕНЕНИЕ МАГНИТНОГО ПОЛЯ ОБРАЗЦОВ Nd-Fe-B-МАГНИТОВ ПРИ ОБЛУЧЕНИИ
ЭЛЕКТРОННЫМ ПУЧКОМ С ЭНЕРГИЕЙ 23 МэВ
В.А. Бовда, А.М. Бовда, И.С. Гук, А.Н. Довбня, В.Н. Лященко, А.О. Мыцыков, Л.В. Онищенко,
С.С. Кандыбей, О.А. Репихов
Были проведены экспериментальные исследования поля четырёх образцов магнита из Nd-Fe-B-сплава,
предварительно намагниченных в импульсном магнитном поле 3,5 Тл. Образцы № 1 и 2 подвергались пря-
мому воздействию электронным пучком с энергией 23 МэВ. Перед образцом № 2 вплотную помещался кон-
вертор из вольфрама толщиной 4,72 мм. Поглощённая доза для образцов составляла 16 Град. Образец № 3
подвергался воздействию тормозным излучением электронного пучка с энергией 23 МэВ. Образец № 4 не
облучался и служил опорным эталоном для калибровки точности метода и контрольных измерений. Наблю-
дается существенное изменение магнитного поля образца № 1, подвергавшегося прямому воздействию
электронным пучком с энергией 23 МэВ. В меньшей мере это изменение наблюдалось для образца № 2. По-
ле вокруг образца № 3 практически не изменилось.
ЗМІНА МАГНІТНОГО ПОЛЯ ЗРАЗКІВ Nd-Fe-B-МАГНІТІВ ПРИ ОПРОМІНЕННІ
ЕЛЕКТРОННИМ ПУЧКОМ З ЕНЕРГІЄЮ 23 МеВ
В.О. Бовда, О.М. Бовда, І.С. Гук, А.М. Довбня, В.М. Лященко, А.О. Мициков, Л.В. Онищенко,
С.С. Кандибей, О.О. Репіхов
Були проведені експериментальні дослідження поля чотирьох зразків магніту з Nd-Fe-B-сплаву, попере-
дньо намагнічених в імпульсному магнітному полі 3,5 Тл. Зразки № 1 і 2 піддавалися прямій дії електро-
нним пучком з енергією 23 МеВ. Перед зразком № 2 впритул містився конвертор з вольфраму товщиною
4,72 мм. Поглинена доза для зразків складала 16 Град. Зразок № 3 піддавався впливові гальмівного випромі-
нювання електронним пучком з енергією 23 МеВ. Зразок № 4 не опромінювався і служив опорним еталоном
для калібрування точності методу і контрольних вимірів. Спостерігається істотна зміна магнітного поля зра-
зка № 1, що піддавався прямій дії електронним пучком з енергією 23 МеВ. У меншій мері ця зміна спостері-
галася для зразка № 2. Поле навколо зразка № 3 практично не змінилося.
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