Simulation of neutron influence on tungsten mirrors
The effect of neutron irradiation on behavior of optical characteristics for two types of tungsten mirrors was modeled. Preliminary irradiated rcW and WJ-IG mirrors with 20 MeV W⁶⁺ ions were used for experiments. Changes in the surface morphology and optical characteristics of the samples were inves...
Gespeichert in:
| Datum: | 2013 |
|---|---|
| Hauptverfasser: | , , , , , , , , , , , , , , , |
| Format: | Artikel |
| Sprache: | English |
| Veröffentlicht: |
Національний науковий центр «Харківський фізико-технічний інститут» НАН України
2013
|
| Schriftenreihe: | Вопросы атомной науки и техники |
| Schlagworte: | |
| Online Zugang: | http://dspace.nbuv.gov.ua/handle/123456789/109239 |
| Tags: |
Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
|
| Назва журналу: | Digital Library of Periodicals of National Academy of Sciences of Ukraine |
| Zitieren: | Simulation of neutron influence on tungsten mirrors / V.S. Voitsenya, A.Kh. Alimov, M. Balden, A.F. Bardamid, A.I. Belyaeva, A.A. Galuza, A.A. Kasilov, I.V. Kolenov, V.G. Konovalov, I.V. Ryzhkov, A.A. Savchenko, A.F. Shtan’, O.A. Skoryk, V.A. Sterligov, S.I. Solodovchenko, B. Tyburska-Püschel // Вопросы атомной науки и техники. — 2013. — № 1. — С. 64-66. — Бібліогр.: 6 назв. — англ. |
Institution
Digital Library of Periodicals of National Academy of Sciences of Ukraine| id |
irk-123456789-109239 |
|---|---|
| record_format |
dspace |
| spelling |
irk-123456789-1092392016-11-22T03:03:36Z Simulation of neutron influence on tungsten mirrors Voitsenya, V.S. Alimov, A.Kh. Balden, M. Bardamid, A.F. Belyaeva, A.I. Galuza, A.A. Kasilov, A.A. Kolenov, I.V. Konovalov, V.G. Ryzhkov, I.V. Savchenko, A.A. Shtan’, A.F. Skoryk, O.A. Sterligov, V.A. Solodovchenko, S.I. Tyburska-Püschel, B. ИТЭР и приложения для термоядерного реактора The effect of neutron irradiation on behavior of optical characteristics for two types of tungsten mirrors was modeled. Preliminary irradiated rcW and WJ-IG mirrors with 20 MeV W⁶⁺ ions were used for experiments. Changes in the surface morphology and optical characteristics of the samples were investigated in the sputtering process. Изучалось влияние нейтронного облучения на поведение оптических свойств двух типов вольфрамовых зеркал rcW и WJ-IG. Зеркала предварительно облучались ионами W⁶⁺ с энергией 20 МэВ. В процессе распыления исследовались изменения морфологии поверхности и оптических характеристик образцов. Вивчався вплив нейтронного опромінення на поведінку оптичних властивостей двох типів вольфрамових дзеркал rcW та WJ-IG. Дзеркала попередньо були опромінені іонами W⁶⁺ з енергією 20 МеВ. Під час процесу розпилення досліджувалися зміни морфології поверхні та оптичних властивостей зразків. 2013 2013 Article Simulation of neutron influence on tungsten mirrors / V.S. Voitsenya, A.Kh. Alimov, M. Balden, A.F. Bardamid, A.I. Belyaeva, A.A. Galuza, A.A. Kasilov, I.V. Kolenov, V.G. Konovalov, I.V. Ryzhkov, A.A. Savchenko, A.F. Shtan’, O.A. Skoryk, V.A. Sterligov, S.I. Solodovchenko, B. Tyburska-Püschel // Вопросы атомной науки и техники. — 2013. — № 1. — С. 64-66. — Бібліогр.: 6 назв. — англ. 1562-6016 PACS: 78.20 Ci; 79.20.Rf http://dspace.nbuv.gov.ua/handle/123456789/109239 en Вопросы атомной науки и техники Національний науковий центр «Харківський фізико-технічний інститут» НАН України |
| institution |
Digital Library of Periodicals of National Academy of Sciences of Ukraine |
| collection |
DSpace DC |
| language |
English |
| topic |
ИТЭР и приложения для термоядерного реактора ИТЭР и приложения для термоядерного реактора |
| spellingShingle |
ИТЭР и приложения для термоядерного реактора ИТЭР и приложения для термоядерного реактора Voitsenya, V.S. Alimov, A.Kh. Balden, M. Bardamid, A.F. Belyaeva, A.I. Galuza, A.A. Kasilov, A.A. Kolenov, I.V. Konovalov, V.G. Ryzhkov, I.V. Savchenko, A.A. Shtan’, A.F. Skoryk, O.A. Sterligov, V.A. Solodovchenko, S.I. Tyburska-Püschel, B. Simulation of neutron influence on tungsten mirrors Вопросы атомной науки и техники |
| description |
The effect of neutron irradiation on behavior of optical characteristics for two types of tungsten mirrors was modeled. Preliminary irradiated rcW and WJ-IG mirrors with 20 MeV W⁶⁺ ions were used for experiments. Changes in the surface morphology and optical characteristics of the samples were investigated in the sputtering process. |
| format |
Article |
| author |
Voitsenya, V.S. Alimov, A.Kh. Balden, M. Bardamid, A.F. Belyaeva, A.I. Galuza, A.A. Kasilov, A.A. Kolenov, I.V. Konovalov, V.G. Ryzhkov, I.V. Savchenko, A.A. Shtan’, A.F. Skoryk, O.A. Sterligov, V.A. Solodovchenko, S.I. Tyburska-Püschel, B. |
| author_facet |
Voitsenya, V.S. Alimov, A.Kh. Balden, M. Bardamid, A.F. Belyaeva, A.I. Galuza, A.A. Kasilov, A.A. Kolenov, I.V. Konovalov, V.G. Ryzhkov, I.V. Savchenko, A.A. Shtan’, A.F. Skoryk, O.A. Sterligov, V.A. Solodovchenko, S.I. Tyburska-Püschel, B. |
| author_sort |
Voitsenya, V.S. |
| title |
Simulation of neutron influence on tungsten mirrors |
| title_short |
Simulation of neutron influence on tungsten mirrors |
| title_full |
Simulation of neutron influence on tungsten mirrors |
| title_fullStr |
Simulation of neutron influence on tungsten mirrors |
| title_full_unstemmed |
Simulation of neutron influence on tungsten mirrors |
| title_sort |
simulation of neutron influence on tungsten mirrors |
| publisher |
Національний науковий центр «Харківський фізико-технічний інститут» НАН України |
| publishDate |
2013 |
| topic_facet |
ИТЭР и приложения для термоядерного реактора |
| url |
http://dspace.nbuv.gov.ua/handle/123456789/109239 |
| citation_txt |
Simulation of neutron influence on tungsten mirrors / V.S. Voitsenya, A.Kh. Alimov, M. Balden, A.F. Bardamid, A.I. Belyaeva, A.A. Galuza, A.A. Kasilov, I.V. Kolenov, V.G. Konovalov, I.V. Ryzhkov, A.A. Savchenko, A.F. Shtan’, O.A. Skoryk, V.A. Sterligov, S.I. Solodovchenko, B. Tyburska-Püschel // Вопросы атомной науки и техники. — 2013. — № 1. — С. 64-66. — Бібліогр.: 6 назв. — англ. |
| series |
Вопросы атомной науки и техники |
| work_keys_str_mv |
AT voitsenyavs simulationofneutroninfluenceontungstenmirrors AT alimovakh simulationofneutroninfluenceontungstenmirrors AT baldenm simulationofneutroninfluenceontungstenmirrors AT bardamidaf simulationofneutroninfluenceontungstenmirrors AT belyaevaai simulationofneutroninfluenceontungstenmirrors AT galuzaaa simulationofneutroninfluenceontungstenmirrors AT kasilovaa simulationofneutroninfluenceontungstenmirrors AT kolenoviv simulationofneutroninfluenceontungstenmirrors AT konovalovvg simulationofneutroninfluenceontungstenmirrors AT ryzhkoviv simulationofneutroninfluenceontungstenmirrors AT savchenkoaa simulationofneutroninfluenceontungstenmirrors AT shtanaf simulationofneutroninfluenceontungstenmirrors AT skorykoa simulationofneutroninfluenceontungstenmirrors AT sterligovva simulationofneutroninfluenceontungstenmirrors AT solodovchenkosi simulationofneutroninfluenceontungstenmirrors AT tyburskapuschelb simulationofneutroninfluenceontungstenmirrors |
| first_indexed |
2025-07-07T22:44:48Z |
| last_indexed |
2025-07-07T22:44:48Z |
| _version_ |
1837029957427003392 |
| fulltext |
64 ISSN 1562-6016. ВАНТ. 2013. №1(83)
SIMULATION OF NEUTRON INFLUENCE ON TUNGSTEN MIRRORS
V.S. Voitsenya1,7, A.Kh. Alimov2, M. Balden3, A.F. Bardamid4, A.I. Belyaeva5, A.A. Galuza6,
A.A. Kasilov1, I.V. Kolenov5, V.G. Konovalov1, I.V. Ryzhkov1, A.A. Savchenko5, A.F. Shtan’1,
O.A. Skoryk1, V.A. Sterligov8, S.I. Solodovchenko1, B. Tyburska-Püschel3
1Institute of Plasma Physics NSC “Kharkov Institute of Physics and Technology”, Kharkov, Ukraine;
2Hydrogen Isotope Research Center, University of Toyama, Toyama, Japan;
3Max-Planck-Institut für Plasmaphysik, EURATOM Association, Garching, Germany;
4Taras Shevchenko National University, Kiev, Ukraine;
5National Technical University “KPI”, Kharkov, Ukraine;
6Institute of Electrophysics and Radiation Technologies, NAS of Ukraine, Kharkov, Ukraine;
7V.N. Karazin Kharkov National University, Kharkov, Ukraine;
8Institute of Semiconductor Physics, NAS of Ukraine, Kiev, Ukraine
The effect of neutron irradiation on behavior of optical characteristics for two types of tungsten mirrors was
modeled. Preliminary irradiated rcW and WJ-IG mirrors with 20 MeV W6+ ions were used for experiments. Changes
in the surface morphology and optical characteristics of the samples were investigated in the sputtering process.
PACS: 78.20 Ci; 79.20.Rf
INTRODUCTION
First mirror (FM) turned to plasma with its working
surface is the responsible element of optical systems of
optical and laser plasma diagnostics in ITER. FMs will
be subjected to influence of all kind radiations
emanating by burning plasma leading to degradation of
their optical properties. Surface erosion under impact of
charge exchange atoms, mainly deuterium and tritium
atoms - CXA, as well as deposition of impurities, will
significantly influence the mirrors properties. The main
requirements at a material choice are high enough
reflectivity and resistance to radiation damage related
with neutron fluxes and CXA bombardment with wide
energy spectra.
Due to a number of unique properties, such as low
sputtering yield and high melting temperature, tungsten
(W) is now considered as a perspective material for the
elements which are plasma facing components in ITER
and probably in DEMO. The total tungsten surface area
in ITER chamber is about 100 m2 [1]. W is also being
considered as a perspective material for FMs placed in
ITER in locations where erosion due to CXAs strongly
dominates. As a result of irradiation by neutrons and
CXAs it is possible the appearance of defects and
changes in the mirrors surface morphology. One of the
ways to investigate the influence of defects from
neutrons effect is to simulate atoms displacement in
solids by irradiation with high-energy ions.
Initially, the experiments simulating neutron effects
on reflectance were provided with Cu and SS mirrors
[2,3], which were exposed to high-energy (1-3 MeV)
ion beams Cu+ and Cr+, respectively. It was found that
degradation of these mirrors under long term sputtering
with hydrogen plasma occurs with approximately
similar rate as that for the mirrors not preliminary
bombarded with high energy metal ions.
EXPERIMENT
The experiments relating to the behavior of
reflectivity and surface morphology of preliminary
irradiated W mirrors due to long term sputtering were
carried out with the use of 600 eV argon ions as
projectiles. Two types of 99.99% polycrystalline
tungsten specimens produced by ALMT Corp., Japan,
were: ITER-grade tungsten (below WJ-IG) and the one
recrystallized at 2073 K for 1 hour after cutting and
polishing (rcW). One side of the mirror specimens were
irradiated with 20 MeV W6+ ions to the damage levels
0.3 dpa and 3.0 dpa. Depth distributions of dose had
maximum at ~1.4 μm and lengthened down to the depth
~2.2 μm [4]. The back side of the specimens served as a
reference surface.
The sputtering process of the surface mirror was
organized as multiply repeated procedures in stand
DSM-2 [5]. After each sputtering procedure the
specimen was taken off from the vacuum chamber and
its mass loss and optical properties were measured.
Optical measurements include measurement of the
reflectance coefficient R(λ) in the wavelength range
λ=220…650 nm at normal incidence of light and
measurements of spectral dependence of ellipsometric
parameters. Micro-images of the specimen surface were
obtained using an optical microscope. After finishing
exposures to argon ions, the surface of specimens was
analyzed with scanning electron microscope (SEM) and
atomic force microscope (AFM). The 2D spatial
distribution of scattered light and X-rays diffraction
(XRD) were measured also. rcW surface was
additionally analyzed with application of confocal laser
scanning microscopy (CLSM) and electron backscatter
diffraction (EBSD).
RESULTS
The results obtained for non-irradiated and irradiated
to 3 dpa and 0.3 dpa sides of both kind tungsten show
that mass loss is almost identical for both specimen
sides and linearly increases with increasing ion fluence.
From these data it may be concluded that there is small
difference between rate of sputtering for sides irradiated
and non-irradiated with W6+ ions. For rcW specimens
the difference in height for adjacent grains increases
ISSN 1562-6016. ВАНТ. 2013. №1(83) 65
with sputtering time (data of interference microscope
and CLSM).
Layer sputtering with thickness ~ 4 μm affected the
surface morphology. Fig. 1 demonstrates change of
interference patterns on the rcW surface after sputtering.
We can see the fringes shift from grain to grain what
means appearance of step structure on rcW mirrors as a
result of long-time polycrystalline materials exposition,
however, in-grain relief does not develop.
Fig. 1. Interference patterns on the irradiated side of
rcW specimen after last exposition
Fig. 2 shows the part of the specimen surface near
the grain with crystallographic axis orientation close to
[111]. This grain dominates over adjacent grains whose
orientation is different from [111] about 9º, and the
value of height difference (Δz) varies from 0.4 to
1.3 μm.
Fig. 2. Step structure of rcW mirror surface after layer
sputtering by thickness ~4 μm. All dimensions are in μm
On Fig. 3 the irradiated (W6+) side of WJ-IG
specimen after sputtering procedures is shown. Notice
that interference patterns become not seen already after
low fluence of D+ ions and a chaotic roughness
appeared.
Fig. 3. Interference microscope data for WJ-IG mirror
irradiated side surface after last exposition
The development of surface inhomogeneity on
WJ-IG specimens began after the first exposure. A 3D
data from AFM of the WJ-IG mirror is shown in Fig. 4.
Such “strange” surface inhomogeneity may be related to
a complicated procedure of preparing this type of
mirrors: (rolling, swaging and/or forging) [6].
Fig. 4. Surface structure of WJ-IG specimen after
sputtering layer with thickness ~ 4 μм. AFM data
Fig. 5 shows the reflection coefficient R(λ) of
WJ-IG and rcW mirrors with 3 dpa damage dose,
depending on the thickness of the sputtered layer at a
wavelength of 600 nm. At normal incidence of light
R(λ) for rcW mirror is practically unchanged, while for
the WJ-IG specimen strong reflectivity degradation was
observed in the serial sputtering process and increasing
of sputtered layer thickness. This behavior of WJ-IG
mirrors is related to the development of roughness on
the specimen surface.
Fig. 5. Dependence of reflection coefficient on the
sputtered layer thickness for WJ-IG and rcW mirrors
irradiated to 3 dpa (points) and not irradiated (dotted
curves) sides at wavelength 600 nm
Fig. 6 shows the ellipsometric parameter Δ spectra
for WJ-IG mirror non-irradiated (initial) and irradiated
sides (3 dpa) with tungsten ions after cleaning, first and
last sputtering procedure.
450 550 650 750
80
90
100
110
120
Δ
, ο
Wavelength, nm
WJ-IG 3dpa (initial side)
Cleaning
Fluence 2.29*1018/cm2
Fluence 64.45*1018/cm2
450 550 650 750
80
90
100
110
120
Δ,
ο
Wavelength, nm
WJ-IG 3dpa (irradiated side)
Cleaning
Fluence 2.29*1018/cm2
Fluence 64.45*1018/cm2
Fig. 6. Ellipsometric parameter Δ on the wavelength for
WJ-IG mirror for non-irradiated (initial) and irradiated
sides after cleaning, first and last sputtering procedure
66 ISSN 1562-6016. ВАНТ. 2013. №1(83)
Δ value for non-irradiated (initial) side of the
specimen is practically unchanged. We can see change
of the parameter Δ, which decreases with increasing ion
fluence for the irradiated side of the mirror. This
behavior indicates that for this type of mirror it is
important if the sample was pre-irradiated or not.
Changes in the ellipsometric parameters for
recrystallized samples weren’t observed and it may be
concluded that the sputtering procedures do not affect
the behavior of normal incidence reflectance for mirror
of this type of tungsten.
Sample surface is characterized by level of scattered
light intensity. An example of such a distribution is
shown in Fig. 7 for the WJ-IG mirror (3 dpa).
Significant intensity anisotropy in azimuth is well seen.
Fig. 7. Normalized data distribution of scattered light
for irradiated side (with 3 dpa damage) of WJ-IG
mirror
CONCLUSIONS
The research related to simulation of neutron
influence on two types of tungsten mirrors surface with
0.3 and 3 dpa damage dose were provided. There was
not found difference in behavior of measured optical
parameters and surface structure for irradiated with W6+
ions and not irradiated specimen sides and in the rate of
sputtering.
Reflectivity of rcW mirrors at normal incidence
changes only within 2 % in all studied spectral range
after sputtering to the depth ~ 4 μm, in spite of
appearance of a typical step structure, what is due to
normal incidence of light. The measured ellipsometric
parameters also showed that specimens surface
irradiation with 20 MeV tungsten ions did not affected
its optical properties.
For WJ-IG samples, in contrast to rcW mirrors, after
the upper layer with thickness ~ 4 μm was sputtered, the
degradation of optical characteristics was observed to
approximately 20 %. Roughness on these specimen
surfaces became to appear already after the first
sputtering procedure with 600 eV Ar+-ions. During the
study some differences in behavior of ellipsometric
parameter Δ on sputter time were observed for
irradiated and non-irradiated side of the mirror.
This work was partially supported by Fund of
Fundamental Research of Ukraine (grant GP/F44/089/).
REFERENCES
1. G. Federici, C.H. Skinner, J.N. Brooks, et al.
// Nuclear Fusion. 2001, v. 41, № 12R, p. 1967-2137.
2. V.S. Voitsenya, V.G. Konovalov, A.F. Shtan’, et al. //
Rev. Sci. Instrum. 1999, v. 70, p. 790.
3. V.S. Voitsenya, A.F. Bardamid, Yu. Borisenko, et al.
// J. Nucl. Mater. 1996, v. 1239, p. 233-237.
4. B. Tyburska, V.Kh. Alimov, O.V. Ogorodnikova,
K. Schmid, K. Ertl // J. Nucl. Mater. 2009, v. 395,
p. 150-155.
5. A.F. Bardamid, V.T. Gritsyna, V.G. Konovalov, et al.
// Surf. Coatings Technol. 1998, v. 103-104, p. 365-369.
6. V.Kh. Alimov, B. Tyburska-Püschel, S. Lindig,
Y. Hatano, et al. // J. Nucl. Mater. 2012, v. 420, p. 519-
524.
Article received 17.01.13
МОДЕЛЬНЫЕ ИССЛЕДОВАНИЯ СВОЙСТВ ВОЛЬФРАМОВЫХ ЗЕРКАЛ
ПРИ НЕЙТРОННОМ ОБЛУЧЕНИИ
В.С. Войценя, А.К. Алимов, М. Балден, А.Ф. Бардамид, А.И. Беляева, А.А. Галуза, А.А. Касилов,
И.В. Коленов, В.Г. Коновалов, И.В. Рыжков, А.А. Савченко, А.Ф. Штань, О.А. Скорик,
В.А. Стерлигов, С.И. Солодовченко, Б. Тубурская-Пушель
Изучалось влияние нейтронного облучения на поведение оптических свойств двух типов вольфрамовых
зеркал rcW и WJ-IG. Зеркала предварительно облучались ионами W6+ с энергией 20 МэВ. В процессе
распыления исследовались изменения морфологии поверхности и оптических характеристик образцов.
МОДЕЛЬНІ ДОСЛІДЖЕННЯ ВЛАСТИВОСТЕЙ ВОЛЬФРАМОВИХ ДЗЕРКАЛ
ПРИ НЕЙТРОННОМУ ОПРОМІНЕННІ
В.С. Войценя, А.К. Алімов, М. Балден, О.Ф. Бардамід, А.І. Бєляєва, А.А. Галуза, А.А. Касілов,
І.В. Колєнов, В.Г. Коновалов, І.В. Рижков, А.А. Савченко, А.Ф. Штань, О.О. Скорик,
В.А. Стерлігов, С.І. Солодовченко, Б. Тубурська-Пушель
Вивчався вплив нейтронного опромінення на поведінку оптичних властивостей двох типів вольфрамових
дзеркал rcW та WJ-IG. Дзеркала попередньо були опромінені іонами W6+ з енергією 20 МеВ. Під час
процесу розпилення досліджувалися зміни морфології поверхні та оптичних властивостей зразків.
|