About unrealization of tungsten lines up to the ground state in the nonideal plasma of pulse discharges in water
The paper considers the dynamics of tungsten impurity absorption line appearance in the plasma channel of the pulse discharge in water (PDW) during the plasma relaxation process. In the initial stage of discharge (3 µs) any tungsten and hydrogen absorption line is not observed in the spectrum. The...
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| Опубліковано в: : | Вопросы атомной науки и техники |
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| Дата: | 2009 |
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| Мова: | Англійська |
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Національний науковий центр «Харківський фізико-технічний інститут» НАН України
2009
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| Цитувати: | About unrealization of tungsten lines up to the ground state in the nonideal plasma of pulse discharges in water / O.A. Fedorovich // Вопросы атомной науки и техники. — 2009. — № 1. — С. 145-147. — Бібліогр.: 11 назв. — англ. |
Репозитарії
Digital Library of Periodicals of National Academy of Sciences of Ukraine| _version_ | 1859616018040619008 |
|---|---|
| author | Fedorovich, O.A. |
| author_facet | Fedorovich, O.A. |
| citation_txt | About unrealization of tungsten lines up to the ground state in the nonideal plasma of pulse discharges in water / O.A. Fedorovich // Вопросы атомной науки и техники. — 2009. — № 1. — С. 145-147. — Бібліогр.: 11 назв. — англ. |
| collection | DSpace DC |
| container_title | Вопросы атомной науки и техники |
| description | The paper considers the dynamics of tungsten impurity absorption line appearance in the plasma channel of the pulse
discharge in water (PDW) during the plasma relaxation process. In the initial stage of discharge (3 µs) any tungsten and
hydrogen absorption line is not observed in the spectrum. The optical gap width ∆Е in the nonideal plasma exceeds
5.5 eV. After 20 µs in the process of plasma relaxation, the absorption lines appear in the spectrum. They correspond to
transitions from the ground level to the levels with higher energies, not exceeding 3.24 eV, i.e. the gap width is 4.74 eV.
After 53 µs the gap width decreases down to 2.22 eV. The estimations of the electron concentration in the plasma,
obtained on the basis of the gap width, and on the plasma frequency, are in a good agreement.
Розглянуто динаміку появи ліній поглинання вольфраму в неідеальній плазмі імпульсного розряду у воді
(ІРВ) при введені в канал домішок металу по мірі релаксації плазми. На початковій стадії розряду (3 мкс) в
спектрі не спостерігається ні одна лінія поглинання вольфраму і водню. Величина оптичної щілини ∆Е
перевищує 5.5 еВ. Через 20 мкс, по мірі релаксації плазми, з’являються спочатку лінії поглинання з переходами
з основного рівня на рівні з верхніми енергіями, які не перевищують 3.24 еВ, тобто з величиною щілини
4.74 еВ, і на 53 мкс величина щілини складає 2.22 еВ. Оцінки концентрації електронів в плазмі, зроблені за
величиною щілини і за плазмовою частотою, добре узгоджуються.
Рассматривается динамика появления линий поглощения вольфрама в неидеальной плазме импульсного
разряда в воде (ИРВ) при введении в канал примесей метала по мере релаксации плазмы. На начальной стадии
разряда (3 мкс) в спектре не наблюдается ни одной линии поглощения вольфрама и водорода. Величина
оптической щели ∆Е превышает 5.5 эВ. Через 20 мкс, по мере релаксации плазмы, появляются вначале линии
поглощения с переходами с основного уровня на уровни с верхними энергиями, не превышающими 3.24 эВ, т.е.
с величиной щели 4.74 эВ, и на 53 микросекунде величина щели составляет 2.22 эВ. Оценки концентрации
электронов в плазме по величине щели и по плазменной частоте хорошо согласуются.
|
| first_indexed | 2025-11-28T19:24:39Z |
| format | Article |
| fulltext |
ABOUT UNREALIZATION OF TUNGSTEN LINES UP TO THE GROUND
STATE IN THE NONIDEAL PLASMA OF PULSE
DISCHARGES IN WATER
O.A. Fedorovich
Institute for Nuclear Research, NASU, Kiev, Ukraine,
E-mail: oafedorovich@kinr.kiev.ua, interdep@kinr.kiev.ua
The paper considers the dynamics of tungsten impurity absorption line appearance in the plasma channel of the pulse
discharge in water (PDW) during the plasma relaxation process. In the initial stage of discharge (3 µs) any tungsten and
hydrogen absorption line is not observed in the spectrum. The optical gap width ∆Е in the nonideal plasma exceeds
5.5 eV. After 20 µs in the process of plasma relaxation, the absorption lines appear in the spectrum. They correspond to
transitions from the ground level to the levels with higher energies, not exceeding 3.24 eV, i.e. the gap width is 4.74 eV.
After 53 µs the gap width decreases down to 2.22 eV. The estimations of the electron concentration in the plasma,
obtained on the basis of the gap width, and on the plasma frequency, are in a good agreement.
PACS.52.80.-s
1. INTRODUCTION
At present time one cannot practically meet in the
literature any data on investigations of metal atom
radiation and absorption spectra in the case of high
plasma densities (except for mercury [1]). The authors of
[2] only noticed that the number of lines corresponding to
the material of conductor, which initiates the pulse
discharge in water (PDW), increases with time, however
the dynamics of their appearance during the plasma
relaxation process was not investigated. Not too many
experimental results on unrealizable levels of metal atoms
can be found also in the review [3]. At the same time in
theoretical works [4-6] a possibility of optical gap
presence in the nonideal plasma with the high degrees of
nonideality is validated.
Thus, there are not enough regular experimental
researches in the given field and, therefore, the task has
been set to investigate the dynamics of the metal line
absorption spectrum with decreasing the degree of PDW
plasma nonideality when impurity metallic atoms are
introduced into the plasma channel.
2.THE MAIN PART
We have carried out investigations using the
equipment with a capacity of discharge batteries of
14.6 µF and a discharge period of 15.5 µs. The diameter
of a tungsten conductor electrode initiating the discharge
was 320 µm, initial voltage 20 Kv, interval between
electrodes 40 mm. In this case the plasma consists, for the
most part, of tungsten atoms and ions.
Let us consider the dynamics of absorption tungsten
line appearance in the spectral range from 488 to 561 nm.
In Figs. 1-3 presented are the microphotograms of the
photometric density distributions of a photofilm in this
range. The microphotogram (Fig. 1) shows that after
3±2 µs of the discharge it is not possible to reveal any line
of tungsten absorption or radiation.
In the ideal plasma in this range of wavelengths there
are observed the tungsten lines with a minimal excitation
potentials, i.e., 2.66 eV (λ = 551.47 nm), gf = 0.0039
(transition from 3326 to 2145 cm-1); 2.48 eV
(λ = 543.5 nm), gf = 0.00063 (transition from 1670 to
20064 cm-1); 2.48 eV (λ = 498.26 nm), gf = 0.0019,
(transition from 0 to 20064 cm-1) and others [7] (gf is the
product of statistical weights and oscillator strengths at
the absorption). The optical gap width is the difference
between the atom ionization potential value (Еi) and the
higher energy excitation of the observable transition with
the greatest excitation potential (Ев): ∆E = Еi – Ев.
However, it is not possible to observe them in the
absorption spectrum during these moments of time. Even
the transitions from the ground state are not observed.
This fact unambiguously proves the existence of an
optical gap effect, and the optical gap width is equal to
ΔЕ ≥ 5.5 eV.
Fig. 1. Microphotogram of the photofilm photometric
density distribution in the spectrum range ∆λ =488-561
nm, t=3±2 µs
Fig. 2. Microphotogram of photofilm photometric density
distribution in the spectrum range ∆λ =488-561 nm,
t=23±2 µs. Absorption lines of tungsten atoms are
marked (the wavelengths are in Ǻ and the excitation
potentials are in eV)
PROBLEMS OF ATOMIC SCIENCE AND TECHNOLOGY. 2009. № 1. 145
Series: Plasma Physics (15), p. 145-147.
mailto:interdep@kinr.kiev.ua
mailto:@oafedorovichkinr.kiev.ua
)exp(1
)exp(1
2
1
3
222
3
111
2
1
12
kT
h
kT
h
fg
efg
W
W kT
EE
υ
υ
λ
λ
−−
−−
×=
−
−
−
In the process of pressure decreasing and slight
increase of brightness temperatures (t = 23 µs), against
the background of continuous spectrum, very broadened
tungsten absorption lines do appear, which belong to the
lower spectral levels with an excitation potential not
higher than 3 eV (Fig. 2). The lower the excitation
potentials, the deeper the downward excursion of tungsten
absorption lines. No line with a higher excitation potential
at this moment of time is observed, the fact testifying
about unrealisation of the upper levels in the microfields
of strongly nonideal plasma. The gap in the absorption
spectrum in this case is equal to ΔЕ = 4.7 eV.
The electron concentration Nе was evaluated by the
formulas of [4, 5]
∆E / kT = (3-4)·γ,
which after transformations takes the form
ΔЕ = (3-4)·Zi·e2·(2Ne)1/3, (1)
and by the formula of [6]:
∆E / kT=2.4·γ3/4, (2),
where ΔЕ is the width of the optical gap in the spectrum,
Ne – electron concentration, Т – plasma temperature, k –
Boltzman constant, γ– degree of plasma nonideality.
For t=3 µs and ΔΕ ≥ 5.5 eV these formulas give,
respectively:
Ne ≥ (2-4)·1021 cm-3 and 5.5·1021 cm-3.
For t=23 µs and ΔΕ ≥ 4.7 eV we obtain the values (3…
7)·1020 and 3·1021 cm-3, and the degree of nonideality γ ≈
2.5 at Te = 104 K. The values Ne found for t = 53 µs and
ΔΕ = 4.54 eV are 1·1021 and 3⋅1021 cm --3, correspondingly.
Fig. 3 Microphotogram of photofilm photometric
density distribution in the spectrum range
∆λ =488-561 nm, t=53±2 µs
Calculations of electron concentration using the
plasma frequency, observed in the spectrum, give for Ne
the values ≈5.0·1021 cm-3 at t=23 µs and ≈4.5·1021 cm-3 at
t=53 µs [9]. Hence the difference between values of Ne,
calculated by two independent methods, is no more, than
factor three. Therefore, to estimate Ne, one may use the
formula given in [6], but for high Ne that formula should
be corrected. The similar values of Ne obtained by two
methods confirm that the intensity dip observed in the
spectrum corresponds to the plasma frequency [8].
To check out the validity of the statement that the
lines with high excitation potentials are not realized, let us
choose several pairs of tungsten lines with different
excitation potentials and very different oscillator strengths
[7]. The brightness temperature of plasma is known, thus
we shall estimate the intensity ratio (of equivalent widths)
for several pairs of lines in the assumption of the
Boltzmann distribution of level population by formulas
[10]:
, (3)
(
∫ −=Ω= kTEegfNdW /
1101 )( υυ ),
where Е1, Е2 are the excitation potentials of the upper
levels of the first and second lines, Т – temperature, W –
equivalent line width, Ω – dependence of absorption
coefficient on frequency, θ – frequency (cm–1). The
concentration N0 of absorbing atoms is absent in the
formula because it is reduced in the definition of the line
width ratio. In this formula the forced transitions are taken
into account also; the gf values are originated from [7].
The calculated results for three pairs of lines are given in
the Table.
# Λ, nm gf Е, eV Т⋅103К W1 / W2
1 506.9
513.8
0.0045
0.88
2.85
5.9 8…11.5 0.443…0.115
2 522.5
524.9
0.023
1.2
2.97
5.76 8…11.5 0.323…0.137
3 551.4
529.2
0.0039
2
2.66
5.94 8…11.5 0.049…0.0183
These results support the classical consideration of
spectra, according to which the lines with a high gf value
should appear in the absorption spectrum without fail,
because their equivalent widths are larger than the width
of lines with small gf value but with low excitation
potentials. This result is an experimental confirmation of
theoretical assumption about disappearance of upper
levels in the strong plasma microfields due to the increase
of the degree of plasma nonideality [5, 6].
Thus, we obtained the experimental evidence of a
nonrealisation effect and optical gap existence in the
nonideal plasma radiation (absorption) spectrum. The
optical gap can achieve 5.5 eV or higher values.
Therefore, all the levels of optical transitions of atoms can
disappear in a strongly nonideal plasma, except the
ground state. As the consequence, when calculating
statistical sums, one has to use the statistical sums of a
nonexcited atom with outer shell electron in a ground
state. Since some levels disappear, the recombination rate
and radiation intensity of the continuous spectrum are
decreasing.
It is obvious from the foregoing: the Boltzman
distribution of the upper level population is disturbed. In
such a case the nonideal plasma can be considered as a
nonequilibrium one. Therefore, to use the “growth
curves” for finding the metal atom density on the plasma
channel surface, as it was done in [11], is impossible due
to disappearance of the upper levels and disturbance of
the Boltzman distribution. The values of Ne, obtained
using the plasma frequency, are in accord with the values
of Ne obtained by the formula of [6] given for an optical
gap ∆Е in the absorption spectrum.
146
3. CONCLUSIONS
At the initial stage of the discharge all the absorption
line levels disappear and the optical gap width in the
spectrum achieves the value ΔЕ ≥ 5.5eV.
With γ decreasing, the gap width decreases too and the
levels with increasingly higher excitation potentials are
observed. The Boltzman population of the upper
absorption line levels is disturbed and, consequently, it
becomes impossible to apply the "growth curves” for
determining the metal atom density on the plasma channel
surface.
The Н α line in the discharge spectrum with high
concentration of metal atom impurities was not observed.
The intensity of recombination spectrum radiation
increases with increasing number of lines that appear in
the radiation and absorption spectra. This is an evidence
of the fact that the recombination coefficient increases
with decreasing the degree of plasma nonideality and
increasing the number of levels, at which the
recombination can occur.
REFERENCES
1. V.M. Batenin, P.V. Minaev. On features of the
behavior of electro-conductivity and dense low-
temperature plasma radiation // TVT, 1971, N 9,
p. 676-682 (in Russian).
2. L.L. Pasechnik, P.D. Starchik, O.A. Fedorovich,
V.V. Yagola. Investigation of the vizible radiation
accompanying the underwater explosion of conductors //
Proceedings of the 3-rd Republican Conference” Scientific
Fundamentals of Electrohydraulic Effect and Their Use
in the Mechanical Engineering and Metalworking,
Nikolaev, 1973, p.41 - 42 (in Russian).
3. A.S. Kakljugin, G.E. Norman. Thermodynamic, optical
and transport properties of low-temperature plasma.
Encyclopedia of low-temperature plasma. Introductory
Volume/ Ed. by Acad. V.E. Fortov. М.: "Science". MAIK,
“Science / Interperiodika”, 2000, Sec. 3, p.402-408 (in
Russian).
4. G.A. Kobzev, J.K. Kurilenkov, G.E. Norman. To the
theory of optical properties of nonideal plasma // TVT(15)
. 1977, N 1, p. 453-460 (in Russian).
5. G.E. Norman. Continuous spectra of nonideal plasma
radiation (absorption). // TVT(17). 1979, N 3. p.453-460.
(in Russian)
6. V.S. Vorobyov, A.L. Homkin. Influence of potential
fluctuations in plasma on the population of high-excited
conditions of atoms // Plasma Physics. 1982, v.8, N 6,
p. 1274-1284 (in Russian).
7. C. Korliss, U. Bozman. Probabilities of transitions and
forces of oscillators of 70 elements. M.: “Mir”, 1968 (in
Russian).
8. O.A. Fedorowich // Problems of Atomic Science and
Technology. Series “Plasma Electronics and New
Methods of Acceleration” (6). 2008, N 4, p. 283-287
(in Russian).
9. Methods of plasma research/ Ed. by V. Lohte-
Holtgreven. M.: “Mir”, 1971 (in Russian).
10. P.P. Kulik, G.E. Norman, L.S. Polak. Chemical
reactions in the nonideal plasma // Chemistry of High
Energies. 1977, v. 11, N 3, p.195-213 (in Russian).
11. R.V. Mitin. Investigation of arc high-frequency and
pulse high-current gas discharges at high (up to 100 atm)
and ultrahigh (up to 2000 atm) pressure: Thesis for a
Doctor’s degree on phys.-math. sciences. Kharkov, 1973
(in Russian).
Article received 9.10.08
.
О НЕРЕАЛИЗАЦИИ ЛИНИЙ ВОЛЬФРАМА ДО ОСНОВНОГО СОСТОЯНИЯ
В НЕИДЕАЛЬНОЙ ПЛАЗМЕ ИМПУЛЬСНЫХ РАЗРЯДОВ В ВОДЕ
О.А. Федорович
Рассматривается динамика появления линий поглощения вольфрама в неидеальной плазме импульсного
разряда в воде (ИРВ) при введении в канал примесей метала по мере релаксации плазмы. На начальной стадии
разряда (3 мкс) в спектре не наблюдается ни одной линии поглощения вольфрама и водорода. Величина
оптической щели ∆Е превышает 5.5 эВ. Через 20 мкс, по мере релаксации плазмы, появляются вначале линии
поглощения с переходами с основного уровня на уровни с верхними энергиями, не превышающими 3.24 эВ, т.е.
с величиной щели 4.74 эВ, и на 53 микросекунде величина щели составляет 2.22 эВ. Оценки концентрации
электронов в плазме по величине щели и по плазменной частоте хорошо согласуются.
ПРО НЕРЕАЛІЗАЦІЮ ЛІНІЙ ВОЛЬФРАМУ ДО ОСНОВНОГО СТАНУ
В НЕІДЕАЛЬНІЙ ПЛАЗМІ ІМПУЛЬСНИХ РОЗРЯДІВ У ВОДІ
О.А. Федорович
Розглянуто динаміку появи ліній поглинання вольфраму в неідеальній плазмі імпульсного розряду у воді
(ІРВ) при введені в канал домішок металу по мірі релаксації плазми. На початковій стадії розряду (3 мкс) в
спектрі не спостерігається ні одна лінія поглинання вольфраму і водню. Величина оптичної щілини ∆Е
перевищує 5.5 еВ. Через 20 мкс, по мірі релаксації плазми, з’являються спочатку лінії поглинання з переходами
з основного рівня на рівні з верхніми енергіями, які не перевищують 3.24 еВ, тобто з величиною щілини
4.74 еВ, і на 53 мкс величина щілини складає 2.22 еВ. Оцінки концентрації електронів в плазмі, зроблені за
величиною щілини і за плазмовою частотою, добре узгоджуються.
147
Е, eV
|
| id | nasplib_isofts_kiev_ua-123456789-88641 |
| institution | Digital Library of Periodicals of National Academy of Sciences of Ukraine |
| issn | 1562-6016 |
| language | English |
| last_indexed | 2025-11-28T19:24:39Z |
| publishDate | 2009 |
| publisher | Національний науковий центр «Харківський фізико-технічний інститут» НАН України |
| record_format | dspace |
| spelling | Fedorovich, O.A. 2015-11-19T20:55:30Z 2015-11-19T20:55:30Z 2009 About unrealization of tungsten lines up to the ground state in the nonideal plasma of pulse discharges in water / O.A. Fedorovich // Вопросы атомной науки и техники. — 2009. — № 1. — С. 145-147. — Бібліогр.: 11 назв. — англ. 1562-6016 PACS.52.80.-s https://nasplib.isofts.kiev.ua/handle/123456789/88641 The paper considers the dynamics of tungsten impurity absorption line appearance in the plasma channel of the pulse discharge in water (PDW) during the plasma relaxation process. In the initial stage of discharge (3 µs) any tungsten and hydrogen absorption line is not observed in the spectrum. The optical gap width ∆Е in the nonideal plasma exceeds 5.5 eV. After 20 µs in the process of plasma relaxation, the absorption lines appear in the spectrum. They correspond to transitions from the ground level to the levels with higher energies, not exceeding 3.24 eV, i.e. the gap width is 4.74 eV. After 53 µs the gap width decreases down to 2.22 eV. The estimations of the electron concentration in the plasma, obtained on the basis of the gap width, and on the plasma frequency, are in a good agreement. Розглянуто динаміку появи ліній поглинання вольфраму в неідеальній плазмі імпульсного розряду у воді (ІРВ) при введені в канал домішок металу по мірі релаксації плазми. На початковій стадії розряду (3 мкс) в спектрі не спостерігається ні одна лінія поглинання вольфраму і водню. Величина оптичної щілини ∆Е перевищує 5.5 еВ. Через 20 мкс, по мірі релаксації плазми, з’являються спочатку лінії поглинання з переходами з основного рівня на рівні з верхніми енергіями, які не перевищують 3.24 еВ, тобто з величиною щілини 4.74 еВ, і на 53 мкс величина щілини складає 2.22 еВ. Оцінки концентрації електронів в плазмі, зроблені за величиною щілини і за плазмовою частотою, добре узгоджуються. Рассматривается динамика появления линий поглощения вольфрама в неидеальной плазме импульсного разряда в воде (ИРВ) при введении в канал примесей метала по мере релаксации плазмы. На начальной стадии разряда (3 мкс) в спектре не наблюдается ни одной линии поглощения вольфрама и водорода. Величина оптической щели ∆Е превышает 5.5 эВ. Через 20 мкс, по мере релаксации плазмы, появляются вначале линии поглощения с переходами с основного уровня на уровни с верхними энергиями, не превышающими 3.24 эВ, т.е. с величиной щели 4.74 эВ, и на 53 микросекунде величина щели составляет 2.22 эВ. Оценки концентрации электронов в плазме по величине щели и по плазменной частоте хорошо согласуются. en Національний науковий центр «Харківський фізико-технічний інститут» НАН України Вопросы атомной науки и техники Низкотемпературная плазма и плазменные технологии About unrealization of tungsten lines up to the ground state in the nonideal plasma of pulse discharges in water Про нереалізацію ліній вольфраму до основного стану в неідеальній плазмі імпульсних розрядів у воді О нереализации линий вольфрама до основного состояния в неидеальной плазме импульсных разрядов в воде Article published earlier |
| spellingShingle | About unrealization of tungsten lines up to the ground state in the nonideal plasma of pulse discharges in water Fedorovich, O.A. Низкотемпературная плазма и плазменные технологии |
| title | About unrealization of tungsten lines up to the ground state in the nonideal plasma of pulse discharges in water |
| title_alt | Про нереалізацію ліній вольфраму до основного стану в неідеальній плазмі імпульсних розрядів у воді О нереализации линий вольфрама до основного состояния в неидеальной плазме импульсных разрядов в воде |
| title_full | About unrealization of tungsten lines up to the ground state in the nonideal plasma of pulse discharges in water |
| title_fullStr | About unrealization of tungsten lines up to the ground state in the nonideal plasma of pulse discharges in water |
| title_full_unstemmed | About unrealization of tungsten lines up to the ground state in the nonideal plasma of pulse discharges in water |
| title_short | About unrealization of tungsten lines up to the ground state in the nonideal plasma of pulse discharges in water |
| title_sort | about unrealization of tungsten lines up to the ground state in the nonideal plasma of pulse discharges in water |
| topic | Низкотемпературная плазма и плазменные технологии |
| topic_facet | Низкотемпературная плазма и плазменные технологии |
| url | https://nasplib.isofts.kiev.ua/handle/123456789/88641 |
| work_keys_str_mv | AT fedorovichoa aboutunrealizationoftungstenlinesuptothegroundstateinthenonidealplasmaofpulsedischargesinwater AT fedorovichoa pronerealízacíûlíníivolʹframudoosnovnogostanuvneídealʹníiplazmíímpulʹsnihrozrâdívuvodí AT fedorovichoa onerealizaciiliniivolʹframadoosnovnogosostoâniâvneidealʹnoiplazmeimpulʹsnyhrazrâdovvvode |