PDA

View Full Version : plasma engine


Karoka
Sep11-10, 11:53 AM
I wanted to ask about plasma propulsion engine. Plasma can be made by using radio waves. How this part of device looks like?(I know something, like an antenna, is used) I searched the net, but I didn't find anything.
Thanks in advance.
P.S Please explain as simple as you can

Astronuc
Sep11-10, 12:02 PM
Basically one simply uses a microwave generator.

For example - http://www.cober.com/why.html

http://www.testbourne.com/instruments/sairem/

Disclaimer: No endorsement is expressed or implied.

Karoka
Sep11-10, 12:09 PM
And microwaves can make ions from any gas? Can it? Because I read that usually xenon is used

Astronuc
Sep11-10, 01:09 PM
Xe is one possibility. Excluding Rn, Xe has the lowest ionization energy of the noble cases. Cs has the lowest ionization energy of the elements.

http://www.lenntech.com/periodic-chart-elements/ionization-energy.htm

Usually one sends a discharge though a gas to ionize it. Then microwaves are used to heat the ionized gas/plasma.

Bob S
Sep11-10, 03:19 PM
And microwaves can make ions from any gas? Can it? Because I read that usually xenon is used
Xenon or other high gram-molecular-weight (GMW) gas is used because a hi-GMW gas has the highest momentum transfer (specific thrust) per unit input energy; p = (2ME)½.

Bob S

Karoka
Sep12-10, 12:21 AM
And then again... Can you tell me how gas can be ionized, that is converted to plasma?

GiftOfPlasma
Sep12-10, 01:59 AM
For devices like: Helicon Double Layer Thruster (http://en.wikipedia.org/wiki/Helicon_Double_Layer_Thruster) and VASIMR (http://en.wikipedia.org/wiki/Variable_Specific_Impulse_Magnetoplasma_Rocket)

Ionization is accomplished with a helical antenna. The antenna launches plasma waves that accelerate electrons that collide with atoms. The collision with the atom sometimes transfers enough energy to an electron in the atom that it's ejected creating an ion and an electron. If this process happens enough the gift of plasma is formed.

RonL
Sep12-10, 10:39 AM
For devices like: Helicon Double Layer Thruster (http://en.wikipedia.org/wiki/Helicon_Double_Layer_Thruster) and VASIMR (http://en.wikipedia.org/wiki/Variable_Specific_Impulse_Magnetoplasma_Rocket)

Ionization is accomplished with a helical antenna. The antenna launches plasma waves that accelerate electrons that collide with atoms. The collision with the atom sometimes transfers enough energy to an electron in the atom that it's ejected creating an ion and an electron. If this process happens enough the gift of plasma is formed.

I would like to ask if you know of any research that has looked at spinning the argon gas into a very high velocity vortex, somewhere in the system ? I see possibilities of heat recovery and separation of gas mass, using centrifuge effects and possible power generation from wasted heat.
This is a question based on thoughts of plasma arch in the center of a vortex, that has been in my mind for some time now.

Thanks
Ron

GiftOfPlasma
Sep12-10, 01:11 PM
I've seen plenty of research on vortex stabilized inductively coupled discharges. My advisor, back when I was in school, did a dissertation on An Experimental Study of Electrodeless Arc Discharges (http://oai.dtic.mil/oai/oai?verb=getRecord&metadataPrefix=html&identifier=AD0729782) using bluff body stabilization. I think the efforts were to make a more conventional type of rocket replacing combustion with an ICP discharge.

Space plasma propulsion using magnetic nozzles requires a much lower collision frequency to function than you would have with a vortex flow. A vortex flow stabilized plasma discharge might have more applications in something like a scram jet but your still left with the problem of powering it.