Experimental investigation of neutron spectra generated in a copper target by 10 MeV protons
The intensity and energy spectra of neutron radiation arising as a result of interaction of the accelerated proton beam with a copper target were measured at a proton energy of 10 MeV. The neutron spectrum was measured using two different techniques: i) with pulse-shape discrimination of gamma-bac...
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Національний науковий центр «Харківський фізико-технічний інститут» НАН України
2004
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| Cite this: | Experimental investigation of neutron spectra generated in a copper target by 10 MeV protons / A.M. Yegorov, V.Ja. Migalenja, V.I. Nagaychenko, V.V. Sotnikov, V.A. Voronko, V.V. Zhuk // Вопросы атомной науки и техники. — 2004. — № 1. — С. 159-161. — Бібліогр.: 4 назв. — англ. |
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Digital Library of Periodicals of National Academy of Sciences of Ukraine| _version_ | 1860105001019375616 |
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| author | Yegorov, A.M. Migalenja, V.Ja. Nagaychenko, V.I. Sotnikov, V.V. Voronko, V.A. Zhuk, V.V. |
| author_facet | Yegorov, A.M. Migalenja, V.Ja. Nagaychenko, V.I. Sotnikov, V.V. Voronko, V.A. Zhuk, V.V. |
| citation_txt | Experimental investigation of neutron spectra generated in a copper target by 10 MeV protons / A.M. Yegorov, V.Ja. Migalenja, V.I. Nagaychenko, V.V. Sotnikov, V.A. Voronko, V.V. Zhuk // Вопросы атомной науки и техники. — 2004. — № 1. — С. 159-161. — Бібліогр.: 4 назв. — англ. |
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| container_title | Вопросы атомной науки и техники |
| description | The intensity and energy spectra of neutron radiation arising as a result of interaction of the accelerated proton beam with a copper target were measured at a proton energy of 10 MeV. The neutron spectrum was measured using two different techniques: i) with pulse-shape discrimination of gamma-background, and ii) by activation detectors.
The neutron yield from the (p,n) reaction was estimated. For the copper target, the neutron yield per accelerated proton of energy 10 MeV was (3.5 ± 1.0)⋅10⁻³.
Проведено вимір енергетичних спектрів і інтенсивності нейтронного випромінювання, генеруемого в
мідній мішені пучком протонів з енергією 10 МеВ. Спектри нейтронів вимірювалися за допомогою двох
різних методик: з дискримінацією гамма-фону за формою імпульсу, а також із застосуванням активаційних
детекторів. Визначено вихід нейтронів з мідної мішені - (3.5±1.0)·10⁻³ на один прискорений протон з
енергією 10 МеВ.
Проведено измерение энергетических спектров и интенсивности нейтронного излучения, генерируемого
в медной мишени пучком протонов с энергией 10 МэВ. Спектры нейтронов измерены с помощью двух различных методик: с дискриминацией гамма-фона по форме импульса, а также с применением активационных
детекторов. Определен выход нейтронов из медной мишени – (3.5±1.0)·10⁻³ на один ускоренный протон с
энергией 10 МэВ.
|
| first_indexed | 2025-12-07T17:31:08Z |
| format | Article |
| fulltext |
EXPERIMENTAL INVESTIGATION OF NEUTRON SPECTRA
GENERATED IN A COPPER TARGET BY 10 MeV PROTONS
A.M. Yegorov, V.Ja. Migalenja, V.I. Nagaychenko, V.V. Sotnikov, V.A. Voronko, V.V. Zhuk
National Science Center “Kharkov Institute of Physics and Technology”,
“Institute of plasma electronics and new methods of acceleration”, Kharkov, Ukraine;
voronko@kipt.kharkov.ua
The intensity and energy spectra of neutron radiation arising as a result of interaction of the accelerated proton
beam with a copper target were measured at a proton energy of 10 MeV. The neutron spectrum was measured using
two different techniques: i) with pulse-shape discrimination of gamma-background, and ii) by activation detectors.
The neutron yield from the (p,n) reaction was estimated. For the copper target, the neutron yield per accelerated pro-
ton of energy 10 MeV was (3.5 ± 1.0)⋅10-3.
PACS: 29.17.+w, 29.27.-a
The aim of the present work has been to measure the
intensity and energy spectra of neutron radiation result-
ing from the interaction of an accelerated proton beam
with a copper target. The measurements were performed
at the U-12 accelerator at an energy of 10 MeV at dif-
ferent positions inside and outside the hall, where the
accelerator is located. The neutron spectra were mea-
sured by two different methods: i) using the stilbene
crystal-based spectrometer NS-2 with the pulse shape
discrimination of gamma-background, and ii) by means
of activation detectors. In the last case, the neutron
spectrum is reconstructed by the method of effective
threshold cross- sections. The data obtained by different
methods are in good agreement. To obtain information
on time characteristics of neutron radiation, the neutron
spectrum was measured simultaneously in the mode of
continuous build-up and in the modes of on and off peri-
ods. Neutron yields from the (p,n) reaction were esti-
mated. For the copper target, the neutron yield per
10 MeV accelerated proton was estimated to be (3.5 ±
1.0)⋅10-3.
1. MEASUREMENT OF SPECTRAL AND
TIME CHARACTERISTICS OF NEUTRON
RADIATION BY MEANS
OF NS-2 SPECTROMETER
The energy spectra of neutron radiation resulting
from the interaction of an accelerated proton beam with
the target were measured at the U-12 accelerator at an
energy of 10 MeV at different positions inside and out-
side the hall, where the accelerator is located. A stilbene
crystal-based spectrometer NS-2 with pulse shape dis-
crimination of gamma-background was used to detect
neutrons. The apparatus spectra of neutrons were pro-
cessed with a microprocessor of the analyzer LP-4900B.
Fig.1 shows the processed data on neutron spectra ob-
tained at location 5 (see Fig.1 of [1]) being at a distance
of 0.5 m from the target at a height of 1.5 m relative to
the hall floor. The measurement time was 1.5 h, the ac-
celerated proton beam energy was 10 MeV, the frequen-
cy was 1 Hz. Fig.2 and 3 show the neutron spectra mea-
sured at the on and off periods, respectively. The neu-
tron spectrum exhibits an exponential character of inten-
sity decrease with time, the total duration being 10 ms.
0 2
0
5
250
7
125
10
375
500
Co
un
ts
Energy, MeV
Fig.1. Neutron energy spectrum measured by the NS-2
at point 5 at a proton energy of 10 MeV
The count information in the neutron channel of the
NS-2 spectrometer was used for measuring the space
distribution of neutrons in the accelerator hall. The val-
ues obtained on the neutron field intensity at certain lo-
cations of NS-2 spectrometer represent the total intensi-
ty of prompt and latent neutrons. The results of neutron
flux intensity measurements (in relative units) are given
in Table 1, which also lists the values of the distance
from the target, R, and the height H (in meters).
Table 1
Place of
measuring
R, m H, m Φn
(relative)
1 3 0 1.0
2 5 1.5 0.06
3 2 1.5 0.11
4 3 1.5 0.06
5 0.5 1.5 2.0
6 2.5 0 0.9
The energy spectrum of neutrons measured at point
1 is mainly contributed by neutrons scattered from
structural elements and walls of the canyon. The aver-
age energy of neutrons detected at point 4 behind the
shield is somewhat higher than the one at point 3 locat-
ed before the shield. This is explained by the fact that
___________________________________________________________
PROBLEMS OF ATOMIC SIENCE AND TECHNOLOGY. 2004. № 1.
Series: Nuclear Physics Investigations (42), p.159-161. 159
the cross section for the interaction of neutrons with the
concrete shield elements decreases with an
0 3
0
6
200
9
100
12
300
400
Co
un
ts
Energy, MeV
Fig.2. Neutron energy spectrum measured by the NS-2
at point 5 at a proton energy of 10 MeV during the on
period (prompt neutrons)
0 3
0
6
100
9
50
12
150
Co
un
ts
Energy, MeV
Fig.3. Neutron energy spectrum measured by the NS-2
at point 5 at a proton energy of 10 MeV at the off peri-
od (latent neutrons)
increasing energy. Therefore, the low-energy part of the
neutron spectrum is attenuated to an appreciably greater
extent as opposed to the high-energy part that carries in-
formation on the proton beam energy.
2. MEASUREMENT OF NEUTRON RADIA-
TION SPECTRAL CHARACTERISTICS BY
MEANS OF ACTIVATION TECHNIQUE
Aside from the neutron spectrometer NS-2, the acti-
vation technique was also used to measure the neutron
spectra. For the purpose, threshold detectors made from
magnesium, iron, zinc, cobalt, etc., arranged along the
axis of the accelerated beam, were used. The total pro-
ton fluence on the target was 3.64⋅1016, the exposure
time was 7.9 h. The rate of activation was determined
from the intensity of gamma-radiation accompanying
the β-decay of radioactive nuclides produced.
The spectrum of neutrons was restored on a method
of effective threshold cross sections [2]. Cross sections
of activation of threshold detectors for energy neutrons
Еn<10МэВ varies rather slowly, therefore it can be ap-
proximated step function, having put cross section of i-
st threshold reaction of below threshold energy i
efE
equal 0, and higher- is constant and equal to i
efσ . Val-
ues of effective thresholds Еi
ef for the used reactions are
resulted in table 2.5 in work [2]. Then speed of activa-
tion of the i-st threshold detector Ai, is connected to
cross section of activation and with spectrum of neu-
trons ϕ(Е) in the following expression:
.)()()( ∫∫
∞∞
⋅⋅=⋅⋅=
thth E
i
efi
E
i dEEdEEEA ϕσϕσ
The effective threshold cross section will be equal to
dEEE
dEEE
i
E
i
i
ef
i
th
⋅⋅
⋅⋅
=
∫
∫
∞
∞
)()(
)()(
0
2
ϕσ
ϕσ
σ ,
where Eth is the threshold of reaction. As a neutron spec-
trum ϕ(E), we took the calculated spectrum of neutrons
generated on the copper target under the action of 10
MeV protons. The calculations were carried out by the
statistical model of the compound nucleus with due ac-
count for the pre-equilibrium decay [3]. With knowl-
edge of effective threshold and the reaction cross sec-
tion, one can determine the integral spectrum value
through the use of the measured activation integrals:
dEEAE
i
efE
i
ef
ii
ef ⋅==Φ ∫
∞
)()( ϕ
σ .
With a set of threshold detectors the neutron spec-
trum is obtained in the form of histograms
ni
EE
EE
E i
ef
i
ef
i
ef
i
ef
i ,...2,1,
)()(
)( 1
1
=
−
Φ−Φ
= −
−
ϕ .
The measured data are presented in Fig.4. The mea-
sured neutron spectrum is identical to the spectrum ob-
tained by neutron spectrometer measurements (Fig.2).
Therefore, the measurements of neutron spectra in con-
tinuous and discrete regimes give identical results.
0 1
0
3
100000
5
50000
7
150000
C
ou
nt
s
Energy, MeV
Fig.4. Neutron energy spectrum measured by means of
activation detectors
160
3. DETERMINATION OF NEUTRON
YIELDS FROM THE COPPER TARGET
The spectra of gamma-radiation that resulted from
induced activity were measured after the accelerator be-
ing operated for 6 hours was switched off. The opera-
tion parameters of the accelerator were as follows: aver-
age pulse current 1.2 mA, beam energy 10 MeV, fre-
quency 1 Hz. The beam was absorbed in the copper tar-
get presenting a set of copper foils with a total thickness
of 340 g/cm2, ensuring the total beam absorption. The
target frame was made from aluminum. In the experi-
ment, we used a Ge(Li) spectrometer situated at 4 m
from the target. A series of 6 measurements was per-
formed during 24 hours following the stop of the accel-
erator. As an additional criterion in the identification of
elements of the corresponding gamma-lines present in
the spectrum, their half-lives were used. The last ones
were determined from the intensity ratios for different
time periods after accelerator stop. Table 2 gives the
main gamma-lines of induced activity.
Table 2
Energy, keV Reaction Half-life
511, 669, 962 63Cu(p,n)63Zn 38.4 m
511, 1115 63Cu(p,n)63Zn 245 d
1368, 2754 27Al(p,α)24Na 15.02 h
1095, 1292 58Fe(n,γ)59Fe 45,6 d
As it follows from the table, the induced activity is
the result of interaction between the primary accelerated
proton beam and the target material, and also between
the secondary neutrons and the structure element mate-
rials. The gross activity at the moment of accelerator
stop was calculated to be (4.2±0.4)⋅1010 Bq and was
mainly contributed by zinc isotopes, i.e., by the copper
activity target. The gross activity of zinc isotopes was
used to estimate the yield of neutrons from the (p,n)-
type reaction on the copper target, since the activity of
radioactive nuclide is determined by the total number of
its nuclei. Taking into account the attenuation of gam-
ma-radiation in the vacuum enclosure of the accelerator
and the decay of zinc nuclide during irradiation, the to-
tal number of neutrons produced was estimated to be
(1.4±0.2)⋅1014. The total proton fluence on the target
was 4⋅1016. Therefore, the neutron yield per accelerated
proton of 10 MeV energy makes (3.5±1.0)⋅10-3 for the
copper target, this being in good agreement with the ear-
lier data [4].
REFERENCES
1. A.M. Yegorov, V.J. Migalenja, V.I. Nagajchenko,
V.V.Sotnikov, V.A. Voronko, V.V. Zhuk. Experi-
mental studies into spectral and time characteristics
of the accelerator u-12 radiation field // Problems
of Atomic Science and Technology. Series: ‘Nucle-
ar Physics Invectigations” (42). 2004, №1, p.153-
155.
2. E.A. Kramer, V.S. Troshin, E.G. Tikhonov. Activa-
tive methods of neutron spectrometry of. М.: “At-
omizdat”, 1976.
3. M. Вlann: Report СОО-3494, 1976.
4. V.K. Daruga. Characteristics of secondary neutron
radiation from the thick targets bombarded by
charged particles with energy 10-50 MeV: The au-
thor's abstract candidate dis., Dubna, 1971.
.
ЭКСПЕРИМЕНТАЛЬНОЕ ИССЛЕДОВАНИЕ СПЕКТРА НЕЙТРОНОВ,
ГЕНЕРИРУЕМЫХ В МЕДНОЙ МИШЕНИ ПРОТОНАМИ С ЭНЕРГИЕЙ 10 МэВ
А.М. Егоров, В.Я. Мигаленя, В.И. Нагайченко, В.В. Сотников, В.А. Воронко, В.В. Жук
Проведено измерение энергетических спектров и интенсивности нейтронного излучения, генерируемого
в медной мишени пучком протонов с энергией 10 МэВ. Спектры нейтронов измерены с помощью двух раз-
личных методик: с дискриминацией гамма-фона по форме импульса, а также с применением активационных
детекторов. Определен выход нейтронов из медной мишени – (3.5±1.0)·10-3 на один ускоренный протон с
энергией 10 МэВ.
ЕКСПЕРИМЕНТАЛЬНЕ ДОСЛІДЖЕННЯ СПЕКТРУ НЕЙТРОНІВ,
ЩО ГЕНЕРУЮТЬСЯ В МІДНІЙ МІШЕНІ ПРОТОНАМИ З ЕНЕРГІЄЮ 10 МеВ
О.М. Єгоров, В.Я. Мігаленя, В.І. Нагайченко, В.В. Сотников, В.А. Воронко, В.В. Жук
Проведено вимір енергетичних спектрів і інтенсивності нейтронного випромінювання, генеруемого в
мідній мішені пучком протонів з енергією 10 МеВ. Спектри нейтронів вимірювалися за допомогою двох
різних методик: з дискримінацією гамма-фону за формою імпульсу, а також із застосуванням активаційних
детекторів. Визначено вихід нейтронів з мідної мішені - (3.5±1.0)·10-3 на один прискорений протон з
енергією 10 МеВ.
А.М. Егоров, В.Я. Мигаленя, В.И. Нагайченко, В.В. Сотников, В.А. Воронко, В.В. Жук
О.М. Єгоров, В.Я. Мігаленя, В.І. Нагайченко, В.В. Сотников, В.А. Воронко, В.В. Жук
|
| id | nasplib_isofts_kiev_ua-123456789-78971 |
| institution | Digital Library of Periodicals of National Academy of Sciences of Ukraine |
| issn | 1562-6016 |
| language | English |
| last_indexed | 2025-12-07T17:31:08Z |
| publishDate | 2004 |
| publisher | Національний науковий центр «Харківський фізико-технічний інститут» НАН України |
| record_format | dspace |
| spelling | Yegorov, A.M. Migalenja, V.Ja. Nagaychenko, V.I. Sotnikov, V.V. Voronko, V.A. Zhuk, V.V. 2015-03-24T15:17:24Z 2015-03-24T15:17:24Z 2004 Experimental investigation of neutron spectra generated in a copper target by 10 MeV protons / A.M. Yegorov, V.Ja. Migalenja, V.I. Nagaychenko, V.V. Sotnikov, V.A. Voronko, V.V. Zhuk // Вопросы атомной науки и техники. — 2004. — № 1. — С. 159-161. — Бібліогр.: 4 назв. — англ. 1562-6016 PACS: 29.17.+w, 29.27.-a https://nasplib.isofts.kiev.ua/handle/123456789/78971 The intensity and energy spectra of neutron radiation arising as a result of interaction of the accelerated proton beam with a copper target were measured at a proton energy of 10 MeV. The neutron spectrum was measured using two different techniques: i) with pulse-shape discrimination of gamma-background, and ii) by activation detectors.
 The neutron yield from the (p,n) reaction was estimated. For the copper target, the neutron yield per accelerated proton of energy 10 MeV was (3.5 ± 1.0)⋅10⁻³. Проведено вимір енергетичних спектрів і інтенсивності нейтронного випромінювання, генеруемого в
 мідній мішені пучком протонів з енергією 10 МеВ. Спектри нейтронів вимірювалися за допомогою двох
 різних методик: з дискримінацією гамма-фону за формою імпульсу, а також із застосуванням активаційних
 детекторів. Визначено вихід нейтронів з мідної мішені - (3.5±1.0)·10⁻³ на один прискорений протон з
 енергією 10 МеВ. Проведено измерение энергетических спектров и интенсивности нейтронного излучения, генерируемого
 в медной мишени пучком протонов с энергией 10 МэВ. Спектры нейтронов измерены с помощью двух различных методик: с дискриминацией гамма-фона по форме импульса, а также с применением активационных
 детекторов. Определен выход нейтронов из медной мишени – (3.5±1.0)·10⁻³ на один ускоренный протон с
 энергией 10 МэВ. en Національний науковий центр «Харківський фізико-технічний інститут» НАН України Вопросы атомной науки и техники Детекторы и детектирование ядерных излучений Experimental investigation of neutron spectra generated in a copper target by 10 MeV protons Експериментальне дослідження спектру нейтронів, що генеруються в мідній мішені протонами з енергією 10 МеВ Экспериментальное исследование спектра нейтронов, генерируемых в медной мишени протонами с энергией 10 МэВ Article published earlier |
| spellingShingle | Experimental investigation of neutron spectra generated in a copper target by 10 MeV protons Yegorov, A.M. Migalenja, V.Ja. Nagaychenko, V.I. Sotnikov, V.V. Voronko, V.A. Zhuk, V.V. Детекторы и детектирование ядерных излучений |
| title | Experimental investigation of neutron spectra generated in a copper target by 10 MeV protons |
| title_alt | Експериментальне дослідження спектру нейтронів, що генеруються в мідній мішені протонами з енергією 10 МеВ Экспериментальное исследование спектра нейтронов, генерируемых в медной мишени протонами с энергией 10 МэВ |
| title_full | Experimental investigation of neutron spectra generated in a copper target by 10 MeV protons |
| title_fullStr | Experimental investigation of neutron spectra generated in a copper target by 10 MeV protons |
| title_full_unstemmed | Experimental investigation of neutron spectra generated in a copper target by 10 MeV protons |
| title_short | Experimental investigation of neutron spectra generated in a copper target by 10 MeV protons |
| title_sort | experimental investigation of neutron spectra generated in a copper target by 10 mev protons |
| topic | Детекторы и детектирование ядерных излучений |
| topic_facet | Детекторы и детектирование ядерных излучений |
| url | https://nasplib.isofts.kiev.ua/handle/123456789/78971 |
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