Radio frequency plasma reactive engine
Збережено в:
| Дата: | 2000 |
|---|---|
| Автори: | , , , , , , , , |
| Формат: | Стаття |
| Мова: | English |
| Опубліковано: |
Національний науковий центр «Харківський фізико-технічний інститут» НАН України
2000
|
| Назва видання: | Вопросы атомной науки и техники |
| Теми: | |
| Онлайн доступ: | http://dspace.nbuv.gov.ua/handle/123456789/78217 |
| Теги: |
Додати тег
Немає тегів, Будьте першим, хто поставить тег для цього запису!
|
| Назва журналу: | Digital Library of Periodicals of National Academy of Sciences of Ukraine |
| Цитувати: | Radio frequency plasma reactive engine / B.V. Zajtzev, Ju.P. Mazalov, V.M. Rashkovan, A.F. Kobetz, B.I. Rudiak, V.M. Sanin, V.A. Bomko, M.S. Lesnykh, V.G. Zhuravlev // Вопросы атомной науки и техники. — 2000. — № 4. — С. 180-181. — Бібліогр.: 4 назв. — англ. |
Репозитарії
Digital Library of Periodicals of National Academy of Sciences of Ukraine| id |
irk-123456789-78217 |
|---|---|
| record_format |
dspace |
| spelling |
irk-123456789-782172015-03-13T03:02:22Z Radio frequency plasma reactive engine Zajtzev, B.V. Mazalov, Ju.P. Rashkovan, V.M. Kobetz, A.F. Rudiak, B.I. Sanin, V.M. Bomko, V.A. Lesnykh, M.S. Zhuravlev, V.G. Физика радиационных и ионно-плазменных технологий 2000 Article Radio frequency plasma reactive engine / B.V. Zajtzev, Ju.P. Mazalov, V.M. Rashkovan, A.F. Kobetz, B.I. Rudiak, V.M. Sanin, V.A. Bomko, M.S. Lesnykh, V.G. Zhuravlev // Вопросы атомной науки и техники. — 2000. — № 4. — С. 180-181. — Бібліогр.: 4 назв. — англ. 1562-6016 http://dspace.nbuv.gov.ua/handle/123456789/78217 533.9 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 |
Физика радиационных и ионно-плазменных технологий Физика радиационных и ионно-плазменных технологий |
| spellingShingle |
Физика радиационных и ионно-плазменных технологий Физика радиационных и ионно-плазменных технологий Zajtzev, B.V. Mazalov, Ju.P. Rashkovan, V.M. Kobetz, A.F. Rudiak, B.I. Sanin, V.M. Bomko, V.A. Lesnykh, M.S. Zhuravlev, V.G. Radio frequency plasma reactive engine Вопросы атомной науки и техники |
| format |
Article |
| author |
Zajtzev, B.V. Mazalov, Ju.P. Rashkovan, V.M. Kobetz, A.F. Rudiak, B.I. Sanin, V.M. Bomko, V.A. Lesnykh, M.S. Zhuravlev, V.G. |
| author_facet |
Zajtzev, B.V. Mazalov, Ju.P. Rashkovan, V.M. Kobetz, A.F. Rudiak, B.I. Sanin, V.M. Bomko, V.A. Lesnykh, M.S. Zhuravlev, V.G. |
| author_sort |
Zajtzev, B.V. |
| title |
Radio frequency plasma reactive engine |
| title_short |
Radio frequency plasma reactive engine |
| title_full |
Radio frequency plasma reactive engine |
| title_fullStr |
Radio frequency plasma reactive engine |
| title_full_unstemmed |
Radio frequency plasma reactive engine |
| title_sort |
radio frequency plasma reactive engine |
| publisher |
Національний науковий центр «Харківський фізико-технічний інститут» НАН України |
| publishDate |
2000 |
| topic_facet |
Физика радиационных и ионно-плазменных технологий |
| url |
http://dspace.nbuv.gov.ua/handle/123456789/78217 |
| citation_txt |
Radio frequency plasma reactive engine / B.V. Zajtzev, Ju.P. Mazalov, V.M. Rashkovan, A.F. Kobetz, B.I. Rudiak, V.M. Sanin, V.A. Bomko, M.S. Lesnykh, V.G. Zhuravlev // Вопросы атомной науки и техники. — 2000. — № 4. — С. 180-181. — Бібліогр.: 4 назв. — англ. |
| series |
Вопросы атомной науки и техники |
| work_keys_str_mv |
AT zajtzevbv radiofrequencyplasmareactiveengine AT mazalovjup radiofrequencyplasmareactiveengine AT rashkovanvm radiofrequencyplasmareactiveengine AT kobetzaf radiofrequencyplasmareactiveengine AT rudiakbi radiofrequencyplasmareactiveengine AT saninvm radiofrequencyplasmareactiveengine AT bomkova radiofrequencyplasmareactiveengine AT lesnykhms radiofrequencyplasmareactiveengine AT zhuravlevvg radiofrequencyplasmareactiveengine |
| first_indexed |
2025-07-06T02:23:03Z |
| last_indexed |
2025-07-06T02:23:03Z |
| _version_ |
1836862497517207552 |
| fulltext |
UDC 533.9
RADIO FREQUENCY PLASMA REACTIVE ENGINE
B.V.Zajtzev, Ju.P.Mazalov, V.M.Rashkovan, A.F.Kobetz, B.I.Rudiak, V.M.Sanin, V.A.Bomko,
M.S.Lesnykh, V.G.Zhuravlev
NSC “Kharkov Institute of Physics and Technology”
Academicheskaya street 1, Kharkov, Ukraine, 310108
Telephone: (0572) 351993, Fax:(0572) 353905, E-mail: nsc@kipt.kharkov.ua
At the present time, designers of plasma reactive
space engines pay especial attention to radio frequency
plasma reactive engines (rf PRE). In such engines, the
working body – quasi-neutral plasma – is formed with rf
discharge [1]. Development of such types of engines
seems to be promising due to the absence of electrodes
prone to electrocorrosion, heated cathodes, keep-alive
electrodes etc., which are used for plasma engines of all
types. That would add to the plasma engine life.
The main problem for the rf PRE development is a
transfer the rf power from the generator to the working
body – low temperature plasma.
For example, it is well known [2] that the average rf
power transferred to the unity volume of gas is:
P 22
2
0
2
2 ϖν
ν
+
⋅=
e
e
m
Ene
where:
E0 –electric field
m - electron mass,
n – electron concentration,
ν – frequency of elastic collisions,
ω – frequency of the applied field
From above one can see that the effective power
exchange is only possible if the frequency of the applied
field does not exceed the frequency of collisions.
NQVe =ν
V- average electron velocity,
N – ion concentration,
Q – collision cross-section
Here N is directly proportional to P and inversely
proportional to the gas temperature
Thus νe usually lies in the range between 109 and 1010
s-1. This value defines the upper limit of rf application.
The lower limit can be defined from the plasma
frequency.
2
1
0
2
42
==
εππ
ϖ
m
nef pl
pl
where:
n – is the electron or ion concentration,
εo – dielectric susceptibility of vacuum,
m – electron mass.
The estimation made with the formula shows that
( ) 2
1
8980 nf pl =
For example, for electron concentration in the range
from 108 to 1014 cm-3 the corresponding plasma
frequencies fall in the range between 100 MHz and 100
GHz. Let us assume that ωpl is one-half period of plasma
oscillations. If ω< ωpl electrons will move in such a way
to create the field of opposite polarity neutralizing the
external field. That screening electron motion tends to
reduce the resulting field in plasma to zero. With ω>ωpl
electrons do not compensate the external field, and it
penetrates plasma. Hence, with ωpl/ω<1 the field
penetrates plasma, and the energy exchange is possible
between electromagnetic wave and plasma. From the
given arguments one can see that the effective low
temperature plasma heating is possible in relatively
narrow frequency range.
The other important factor that influences rf
application in reactive space engines is technical
parameters of their construction. It is known that
traditionally for plasma keeping and heating with a high
frequency field cavities of different kinds were used due
to rf energy accumulation in them. However, in an
“empty” (without plasma) cavity tuned to a certain
frequency, with initiation of the discharge an additive
conductivity arises that consists of normalized active
and reactive conductivities [3,4]. The active component
of the conductivity causes the change in the internal
resistance of the cavity that leads to a drop in Q. The
reactive component of conductivity changes the
eigenfrequency of the cavity, and necessity arises to
adjust the frequency of the generator-engine system.
The absorbed power depends both on the value of
mismatch of resistors and on the frequency
mismatching. Hence for the application of the cavity as
a construction for rf reactive engines it is necessary to
match rf generator with every initiation of the engine, or
to adjust the engine parameters with adjusting elements,
though it is extremely undesirable.
Taking into consideration the above, we set
ourselves a task of development and examination the
engine without the indicated drawbacks. A short length
of the coaxial line with the wave resistance ρ =75 Ohm,
500 mm in total length, and external diameter of 100
mm was chosen as a basis for the construction. The
specified overall sizes are not critical, as they were the
sizes of the waveguide elements available. In principle,
the specified sizes can be varied in reasonably wide
limits. The matter of fact that with the initiation of the
discharge inside a coaxial, its parameters, frequency,
and resistance were changed as it was mentioned above,
the antinode of current moved along the coaxial. And as
180 ВОПРОСЫ АТОМНОЙ НАУКИ И ТЕХНИКИ. 2000. № 4.
Серия:Физика радиационных повреждений и радиационное материаловедение (78), с. 180-181
one end of the coaxial was disconnected and presented a
shortening capacity built as a cone adapter to the coaxial
smaller in diameter, the section of the coaxial from the
antinode of current to the antinode of voltage presented
a quarter-wave cavity for the given generator frequency.
Therefore, in the described construction a kind of
automatic matching to resonant mode takes place. It is
only necessary to select the value of the shortening
capacity in such a way that the antinode of the current
would remained always inside the construction. The
cone adapter, which we used as a shortening capacity
played one more important part. With it the necessary
value of the electric field intensity was provided for the
rf breakdown and initiation of the discharge that was
about 140-170 V/cm in our experiments, the value of
the gap between the central and outer conductors was 8-
10 mm and could be regulated in the course of the
experiment. At the other end the coaxial also had a cone
adapter, which ended with 75mm terminal; it was used
to supply rf power form the generator. In our
experiments the coupling between the generator and the
construction under investigation was ruled out
(henceforth, module for short) with a loop or a rod as in
that case it is difficult to provide the matching between
the module and the generator. In the body of the module
there were holes for pumping out and intake of the gas.
Air was used as a working body. The first experiments
were carried out in the pulse mode. The power supplied
to the module was 1400 W at the active load was 75
Ohm. The rf pulse duration τ was 400μs with pulse
frequency 2Hz. When the pressure about 1 torr is
achieved the discharge was initiated inside the module,
which could be observed in the inspection window. In
the process of the discharge glowing the control of
incident and reflected waves was being carried out. The
comparative calculations have shown that the absorbed
rf power is 500 W that is 30% of the supplied power.
As the construction of the installation did not permit
to carry out direct measurements of the thrust of the
module we had carried out an experiment to prove
qualitatively the positive effect of the rf discharge. In
the course of the experiment the right (operating)
section of the module was placed in the vacuum
volume, and a hole in the cone – a nozzle – were
reasonably large, the diameter was 15 mm. With the
pump and the vacuum volume that closed the module,
the pressures inside and outside the module at the
nozzle section were leveled.
Diaphragm made of the metal foil 30x40 mm in size
was placed at the distance of 20 mm from the nozzle
section. It was noted that at the moment of the rf power
pulse delivery to the module the discharge was initiated
in it, and at that time a sharp deflection of the
diaphragm took place. That indicates that at the moment
the pressure inside a module increases sharply, and the
exhaust of the gas from the nozzle to the vacuum
volume occurs. It is rather difficult to carry out
quantitative measurements of the module parameters in
the pulse mode. Because of this, having improved the
construction of the module we came to experiments
with the generator operating in the continuous mode.
We assembled a generator that provided continuous rf
power about 260-270 W with the active load of 75
Ohm. An eigenfrequency of the generator was 120MHz.
The operating pressure was 0.5-1 torr. With rf power
supply to the module the discharge initiates in it. With
that the absorbed power is 60 W. In the process of
discharge glowing considerable heating of the module
surface occurs in the place of the maximal electric field.
With the pressure increase to 1.5-2 torr the discharge
glowing weakens, and with the further increase it fades.
That indicates that the power of the generator is not
enough to keep the discharge glowing. It is necessary to
increase the generator power to 1-2 KW. In the process
of the discharge glowing a slight frequency departure of
about 1-5 MHz is observed. At the present time a
module is under construction that could be placed to the
special measuring test-bench and to carry out direct
thrust measurements.
The previous show that rf energy application in gas
dynamic engines can result in various positive effects as
the increase in thrust, specific pulse, saving in the
working body, and in increase in the service life.
Further experimental investigation and development of
these engines can made them competitive to plasma
engines and in some cases their application will be
preferential.
References
1. Mackel W.E. // Fast interplanetary mission with
low thrust propulsion systems. 1961 NASA
Tech.Rept. TR-79
2. L.A.Artzimovich // The elementary plasma physics,
1966, M,: Atomizdat
3. V.M.Batenin, I.I.Klimovskij, G.V.Lysov,
V.N.Troitzkij // Rf plasma generators. 1988. M.:
Energoatomizdat
4. A.M.Chernushenko, B.V.Petrov, A.G.Maloratzkij
et al. // Design of screen and rf devices, 1990.
“Radio i svjaz”
RADIO FREQUENCY PLASMA REACTIVE ENGINE
NSC “Kharkov Institute of Physics and Technology”
References
|