how do you make plasma?
Chris
Can you make plasma using a coil with a tube of low pressure hydrogen gas
inside? If so can someone give me details or point to a book that gives full
details for making a plasma like that.
--
Chris
http://www.myphilosophy.eu
Jim Logajan
"Chris" <nor...@noserver.com> wrote:
> Can you make plasma using a coil with a tube of low pressure hydrogen
> gas inside? If so can someone give me details or point to a book that
> gives full details for making a plasma like that.
It is difficult to know what you are trying to do given your short
description. So it is difficult to give advice. Still, I would suggest
the following book, even though it only partially addresses some of what
you need to know:
"Building Scientific Apparatus" by Moore, Davis, and Coplan.
Tooned In
Or search for all plasma related books, and visually filter those more
specific to your needs:
<http://www.amazon.com/s/ref=nb_ss_b?url=search-alias%3Dstripbooks&field-keywords=plasma>
Chris
I would like to know what EMF I need to ionise hydrogen and once ionised how
much current I would get for a particular EMF. I would like to use induction
from a radio frequency current in the coil to do it. What frequency do I
need and what EMF across the coil and what RF current?
Where would I get the RF current from?
--
Chris
http://www.chrisspages.co.uk
"Jim Logajan" <Jam...@lugoj.com> wrote in message
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Jim Logajan
"Chris" <chris-rem...@chriss-remove-pages.co.uk> wrote:
> I would like to know what EMF I need to ionise hydrogen and once
> ionised how much current I would get for a particular EMF. I would
> like to use induction from a radio frequency current in the coil to do
> it. What frequency do I need and what EMF across the coil and what RF
> current?
The ionization energy of monatomic hydrogen can be found in many different
reference sources. It is 13.6 eV. For the H2 molecule the binding energy of
the hydrogen atoms to each other appears to be about 15.4 eV.
I strongly suggest you do a library or Internet search for "plasma
generation" or "plasma sources".
That said, here are a few of my own simple observations:
If you start with a mostly un-ionized hydrogen molecule gas at room
temperature, there are several possible energy transfer modes that I can
think of where low frequency RF might supply some heating energy, but I
don't know that anybody does things that way. It would be incredibly
inefficient. My understanding is that generally a bit of seed plasma is
created using electro-static discharge, or thermionic emission, or similar.
The seed plasma is then heated further using ohmic heating, RF induction,
compression, laser, or other mechanisms.
Otherwise I believe you will have to use frequencies where the energy of
the photons is comparable to the binding and ionization energies in
question - on the order of wavelengths of 90nm to 100nm. Basically far
ultraviolet.
> Where would I get the RF current from?
A far ultroviolet laser (excimer or free electron) seems to be one
possibility. But if you examine how those devices work, that suggests that the
initial problem is merely pushed off to another device.
Chris
What about the Paschen curve for hydrogen?
--
Chris
http://www.chrisspages.co.uk
"Jim Logajan" <Jam...@lugoj.com> wrote in message
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Jim Logajan
I would assume that would be applicable if you wish to utilize
electrostatic forces for generating a plasma rather than transfer of energy
via RF. This link seems to have relevant data:
Chris
I thought the E field of a radio frequency emission was the same as a static
field so the breakdown potential has to be supplied by the E field of the RF
power. P=ExH and since H is related to E P=E^2 times a constant which I
think is u/e. So to cause a plasma with RF in hydrogen at 0.001 Torr the E
field has to be:
273V at 1.15torr-cm 273 at 1.15 torr 1cm
273V at 0.001 Torr 1150 cm ie 23.7 volts/meter That is a power of 4.8 x root
u/e =4.8xroot 8.85E-12/1.25E-6=906x4.8=4.3KW
Is that correct?
--
Chris
http://www.chrisspages.co.uk
"Jim Logajan" <Jam...@lugoj.com> wrote in message
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Chris
I made two calculations one said 2 watt the other 3000 watt. I know by
experience 2 watt is not enough, so 3KW is more likely to be able to ionise
hydrogen and generate a plasma in hydrogen at 0.001 torr.
--
Chris
http://www.chrisspages.co.uk
"Jim Logajan" <Jam...@lugoj.com> wrote in message
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Chris
I make it
Pd = E2 / Z0
where E is the electric filed in V/m and the Z0 is free space impedance (Z0
=? / ? =120 ? , ?). (looked up)
Power=e/uE^2 E=28 volts/meter Power =28^2/120pi=2.08 watts to ionise
hydrogen at 0.001 torr.
--
Chris
http://www.chrisspages.co.uk
"Jim Logajan" <Jam...@lugoj.com> wrote in message
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anon...@noserver.com
I made hydrogen plasma by putting my tube of low pressure hydrogen into an
850 watt microwave oven. It struck ofter 2 seconds with a red light then it
went yellow and became incandescent white hot.
--
Chris
anon...@noserver.com
I'm still trying to make plasma using the inductor of a Hartley oscillator
with an anode potential of 500 volts. I've tried a tube with hydrogen at 3
Tor, 0.001 Tor and 1 microbar. I can light a fluorescent tube but I cannot
ionise the hydrogen.
Has anyone any idea what pressure to use so I can ionise the hydrogen as
easily as light the fluorescent tube?
--
Chris
Chris
I found a document highly relavent to what I am doing. It appears from this
document that the estimates for power and pressure are in the right order.
I can make plasma with my microwave oven. The mechanism involves heating the
gas with the microwave energy and then the glow discharge starts when it
reaches a critical level.
It also appears that the first stage is a townsend discharge which does not
glow. This is where the gas gets hot with the small current flowing.
--
Chris.
London,
UK.
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"Jim Logajan" <Jam...@lugoj.com> wrote in message
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