Sciencemadness Discussion Board

Plasma reactor- Confinement,Heat sources

FPMAGEL - 15-10-2005 at 16:16

I've been keen on plasma for a while, from explosive to spark gaps. Today i was looking up fusion web sites and thought i might try to see if i can make a structure(in a garge) to contain the plasma from rockets or high voltage.

I'am starting with some carbon steel 11cmD pipe, which i'am going to weld two flat plates on each end with a 5cm hole in the base and top, were i will insert two electrodes(1cm),with 4mm of cermics to hold it together. The electrodes will have a spaceing of 2mm. I will be using a car ignition coil and a 240/12 tranfomer from the mains 240v*20a == 12v *400a = 4800w. This small sparkgap hopefuly after awhile should start to iodize the air dropping the conductive of air from 50,000v/1mm down to 400v/1mm

This test should tell me the effect a magntic feild has on plasma(try welding carbon steel with a magtnic, it doesn't work to well), and the tempture which can be reached.

IrC - 15-10-2005 at 18:28

Your coil will short out in seconds, your plasma if any will radiate it's energy through the walls as heat and your steel container will make it impossible for any kind of magnetic confinement. Is this a trick question or something? The ignition coil isn't designed for more than an ampere or so, and even that is not RMS power at 50 or 60 cycle sine waves. Properly designed a capacitor is charged up and dumped into the primary in a cyclic fashion, and the output wouldn't ionize more than a bug killer. I won't even bother going into the 4.8 KW you magically came up with.

[Edited on 16-10-2005 by IrC]

FPMAGEL - 15-10-2005 at 19:41

"You coil will short out in seconds, your plasma if any will radiate it's energy through the walls as heat"
I was thinking about that 400 amps, the wires are about 3mm thick on the transfomer at 400 amp they will most likely heat up to quickly. As the air inside can't leave it should not leak the iodized air(The main task, to get iodized gas, secondary task 5000C), the only thing which whould stop it building up(maybe), is the steel will conduct the electrons away. I might need to have glass pipe inside the metal one.

"steel container will make it impossible for any kind of magnetic confinement. Is this a trick question or something?"
No. copper wire and current wrapped around carbon steel will make a magnetic field

"The ignition coil isn't designed for more than an ampere"
A car alternator produces 100amp, which get feed to the battery or igntion coil. The secondary windings is about 50,000v .5a, primary 12v 60-80a(car),100-120a(truck)

"and even that is not RMS power at 50 or 60 cycle sine waves."
I know what you mean, inverters need AC current.

"I won't even bother going into the 4.8 KW you magically came up with."
the mains in this country have 35amp max at 240volts = 8400watts or volts times amps.

Thanks i didn't think about electrons getting absorbed by the steel.



[Edited on 16-10-2005 by FPMAGEL]

[Edited on 16-10-2005 by FPMAGEL]

IrC - 15-10-2005 at 20:55

I give up, but you are welcome for something I'm not sure what.

Marvin - 15-10-2005 at 22:07

I think what IrC is trying to say, is that nothing you have said will work and you wouldnt understand why if we told you.

Try getting hold of the largest Xenon tube you can find and using that with a low current high voltage power supply. You can then put magnets very close to the arc and see it coil up into loops. Success on a small scale is easier and when things go wrong, as at first they certainly will it will be more obvious why.

FPMAGEL - 15-10-2005 at 22:40

"You can then put magnets very close to the arc and see it coil up into loops."
Nice, why does it do that.

"I think what IrC is trying to say, is that nothing you have said will work and you wouldnt understand why if we told you."
I would be greatfull if you could try, but i understand were you are going,very funny, strange it wasn't logical on your part, as only espoinage unit would know so much about me,Understand?.

IrC - 16-10-2005 at 00:23

" as only espoinage unit would know so much about me,Understand?."

??????????????????

I just figured it all out. This is all in code, and it can only be read from the Detritus forum!

Being nice, electrons are deflected as they travel through a region containing a magnetic field. Type "right hand rule" into google and go from there. Thought I would add that while it was still possible to post in this thread?

[Edited on 16-10-2005 by IrC]

vulture - 16-10-2005 at 08:00

Closing this thread is a bit too soon, but FPMAGEL, if you want help, make sure your questions are understandable and that you've done some prior research. Both conditions aren't even slightly met!

If you want to contain plasma, start by putting a light bulb in your MW oven.

[Edited on 16-10-2005 by vulture]

IrC - 16-10-2005 at 11:40

FPMAGEL, you might also check out these links:

http://www.amasci.com/weird/microexp.html

http://apache.airnet.com.au/~fastinfo/microwave/

FPMAGEL - 16-10-2005 at 13:25

Thanks for the links.

Talking about efficient, what would you say would be the easyist to make a plasma with. RF waves(Microwaves), or a static discharge(van-de-grafs),sparkgap

", electrons are deflected as they travel through a region containing a magnetic field. Type "right hand rule"
Would that make it easy for the plasma to go in one direction easyer than the other.

I've got the gear for the sparkgap, but not the microwave. I saw on sky about Edison, they had two plates,about 15cmD and about 20cm apart, the person could put there hand throught with out being burnt(Heard its good for decom).Q) would this act like a capactor, or use the same princilpes.



www.fusion.org.uk

FPMAGEL - 16-10-2005 at 13:39

Reactor pic

reactor.bmp - 75kB

IrC - 16-10-2005 at 14:35

I think this thread should be in beginnings but as to the best way for you to make a plasma you should try Marvin's idea using the car ignition coil powered by a properly designed circuit, or Vulture's idea using a standard kitchen microwave oven. Of course stress safety and this includes not getting blasted by your parents if you burn up the kitchen microwave. Your pennance may be eating cold food for a long time.

", electrons are deflected as they travel through a region containing a magnetic field. Type "right hand rule"
"Would that make it easy for the plasma to go in one direction easyer than the other."

As to this what I was saying was go and google, study and then ask these questions.

12AX7 - 16-10-2005 at 16:21

I see two common themes here:
1. To iodize air, you evaporate iodine into it. See how that works? I don't know what the hell you'd want iodized air for, and it sure as heck doesn't have anything to do with plasma, unless you want to study iodine's behavior in a plasma. You probably mean ionize.
2. You still drew the steel shield around the device. This will direct magnetic field away from the experiment, which I'm guessing the intention was to confine the plasma with an axial magnetic field.

Oh, and three: go read a book, or twenty! Not only do you have no concept of plasma physics, but I doubt you even have any grasp of the underlying concepts -- quantum physics, even classical physics for that matter, electric and electromagnetic behavior, etc. Plus the calculus needed to finagle and evaluate equations for these systems.

Tim

FPMAGEL - 16-10-2005 at 17:39

"I don't know what the hell you'd want iodized air for, and it sure as heck doesn't have anything to do with plasma,"
When i get the air ionized(sorry it look like iodine) i will send a ac current high HZ throught the copper to vibrate the elctrons to produce heat, for cutter/razers/cleaners/O3 etc

"2. You still drew the steel shield around the device. This will direct magnetic field away from the experiment, which I'm guessing the intention was to confine the plasma with an axial magnetic field. "
True, axial Mfield is that M or E. If it doesn't work those people that biuld electric motors will be pissed of.Experment take a carbon steel pipe and wrap copper wire around it, and send a current throught it. Then place a nail in the middle, will it be attracted to the pipe on the inside.

"Oh, and three: go read a book, or twenty! Not only do you have no concept of plasma physics,"
Yes i should, and you know the rest i should add.

I know Irc is just posting to piss me off, and know i think you are as will
FACTS.FACTS not you are dum, god damn mirrors they are everwhere, even were you least expect.

80% crap, its getting close to my prediction of 95%. And saying this will proalbe have the effect intended, to close the thread.

IrC - 16-10-2005 at 18:57

"just trying to piss you off"?

I was trying to give you some helpful ideas but since you feel that way so be it. I will not bother you with technical help any further.

FPMAGEL - 16-10-2005 at 19:10

"I was trying to give you some helpful ideas but since you feel that way so be it. I will not bother you with technical help any further."
:D
So i will go and "search google", very helpfull and technical, and i did say thank you for the links



[Edited on 17-10-2005 by FPMAGEL]

[Edited on 17-10-2005 by FPMAGEL]

Quince - 17-10-2005 at 02:16

Electrode erosion is in general a big problem in plasma systems. This is the main advantage of RF, and now power levels achieved are making it competitive. The possibilities for space travel are grand. Check this out:
http://www.ess.washington.edu/Space/propulsion.html
Also, this new implementation of an old idea will allow the weakness of plasma propulsion, low thrust, to be dealt with and possibly result in its use in even launch vehicles:
http://www3.inspi.ufl.edu/space/program/abstracts/1146.pdf

[Edited on 17-10-2005 by Quince]

Bander - 17-10-2005 at 03:02


The device detailed in the below references works by ionizing oxygen entrapped in a helium stream between two copper rings in a glass pipe at ATMOSPHERIC PRESSURE. The high voltage electrical pulses are shaped such that peak powers are in the megawatts but the energy in each pulse is very low (millijoules, I believe). An appropriately low inductance marx generator may be able to pull this off, but I don't know if a marx can do the pulse-rate required. Anyway, a general information thrust into pulsed power and pulse shaping circuitry may be needed to build such a device.

Room-temperature atmospheric pressure plasma plume for biomedical applications
Quote:

As low-temperature nonequilibrium plasmas come to play an increasing role in biomedical applications, reliable and user-friendly sources need to be developed. These plasma sources have to meet stringent requirements such as low temperature (at or near room temperature), no risk of arcing, operation at atmospheric pressure, preferably hand-held operation, low concentration of ozone generation, etc. In this letter, we present a device that meets exactly such requirements. This device is capable of generating a cold plasma plume several centimeters in length. It exhibits low power requirements as shown by its current-voltage characteristics. Using helium as a carrier gas, very little ozone is generated and the gas temperature, as measured by emission spectroscopy, remains at room temperature even after hours of operations. The plasma plume can be touched by bare hands and can be directed manually by a user to come in contact with delicate objects and materials including skin and dental gum without causing any heating or painful sensation. ©2005 American Institute of Physics
Further places to find information:
http://www.physicsweb.org/articles/news/9/9/11/1 - overview
http://physicsweb.org/articles/news/7/4/19 - As sterilization technique
http://www.ece.odu.edu/~mlarouss/ - lab page
http://www.google.com/search?q=%22Laroussi%22+%22Low+Tempera...

---
Edit, here is a good overview that is free fulltext. Also, yes, it would seem that a marx topology can in no way do 13Mhz. Heh. The 13.56 MHz refernced in the article below, though, does happen to be a frequency used in RFID tags. Perhaps a driver could be hacked up from sampled commodity RFID chips coupled with an appropriately powerful RF amp in that region. I believe this may be the best method for stable homebrew plasmas. Helium isn't that expensive anyway. I am not sure about pulse shaping at these frequencies. Perhaps we're lucky and my initial interpetation of the technology was incorrect and no pulse shaping is needed.
Quote:
Gas breakdown in an atmospheric pressure radio-frequency capacitive plasma source
Jaeyoung Park,a) I. Henins, H. W. Herrmann, and G. S. Selwyn
Plasma Physics, Los Alamos National Laboratory, Los Alamos, New Mexico 87545
~Received 3 July 2000; accepted for publication 13 September 2000!
Gas breakdown is studied in an atmospheric pressure rf capacitive plasma source developed for
materials applications. At a rf frequency of 13.56 MHz, breakdown voltage is largely a function of
the product of the pressure and the discharge gap spacing, approximating the Paschen curve.
However, breakdown voltage varies substantially with rf frequency due to a change in the electron
loss mechanism. A large increase in breakdown voltage is observed when argon, oxygen, or
nitrogen is added to helium despite their lower ionization potential. Discussion is given for optimal
breakdown conditions at atmospheric pressure. © 2001 American Institute of Physics.
@DOI: 10.1063/1.1323754#


[Edited on 17-10-2005 by Bander]

darkflame89 - 17-10-2005 at 03:26

Another way to confine plasma, by electrostatic means... Google this : Farnsworth-Hirsh fusor. Its simply just 2 steel electrodes that are spherical, placed within one another. Apply HV, ionized gas will smash at high speeds and get confined in the center.

Constrains: you need a good vacuum pump, an extremely good one. And a bottle a deuterium gas.

Quince - 17-10-2005 at 15:51

Fusor -- terrible efficiency, and watch out for neutron emissions damaging yer family jewels. Better get out those wax block neutron absorbers. Probably significant gamma as well, so make the windows lead glass.

Specifically on propulsion, check out the plasma propulsion thread I started last night in this forum.

Twospoons - 17-10-2005 at 18:44

The bigger danger with the fusor is the hard X-rays that are produced well before neutron emission begins.

Neat links Bander - I'm definitely going to have to play with with RT plasma stuff.

FPMAGEL - 17-10-2005 at 19:53

On wednesday i'am getting a alternator , so i should be albe to test this design hopefull.

Razar

[Edited on 18-10-2005 by FPMAGEL]

ra.bmp - 198kB

Quince - 17-10-2005 at 20:30

And here's the image at same quality but 2% of the size.
Posting uncompressed bitmaps just wastes bandwidth.
And if you make the spacing of the X-ray windows just right, you should be able to sterilize both of your gonads simultaneously, thus doing your not-so-small part of keeping our gene pool nice and clean.

~~~~~
Quote:
Originally posted by vulture
your MW oven.

Oh man, I wish I had a MegaWatt oven too!

Gotta love the overuse and abuse of abbreviations by lazy posters. :P

[Edited on 18-10-2005 by Quince]

ra.png - 4kB

FPMAGEL - 17-10-2005 at 21:58

"Helium isn't that expensive anyway"
bander were do you buy it from,The only people i havn't tryed is chemical supplers, no ticket.


"And if you make the spacing of the X-ray windows just right, you should be able to sterilize both of your gonads simultaneously, thus doing your not-so-small part of keeping our gene pool nice and clean. "


http://www.astro.unibonn.de/~jkerp/ag_hp/sxrb.html
If i understand this correctly some paper might help. Not to metion that red curtain you use for weilding stops IR/UV/Soft x-ray

http://www.inst.bnl.gov/GasDetectorLab/x-rays/x-ray_microsco...

"And here's the image at same quality but 2% of the size.
Posting uncompressed bitmaps just wastes bandwidth. "
From 1sec too what 1/4sec,damn get dial-up


[Edited on 18-10-2005 by FPMAGEL]

Quince - 17-10-2005 at 22:10

I'm not talking about my bandwidth, as I have cable. I'm talking about the server's bandwidth, which the forum owners have to pay for.

BTW, you should be careful how seriously you take stuff posted on anonymous message boards. You should learn to figure out when people are just talking trash, trolling for reactions, posting tongue-in-cheek messages, or being a devil's advocate.

Regarding helium: you don't need it. You can easily achieve breakdown of atmospheric pressure air with a microhollow cathode and use it as the electron source for your plasma. I've already posted about this, as you'd find if you use the search function. Take a look at the references I listed. The basic principle is fairly straightforward, though as usual, the devil's in the details.

[Edited on 18-10-2005 by Quince]

LSD25 - 3-2-2008 at 02:31

This is seriously the scariest thing I have ever seen an amateur chemist do at home:

http://www.diane-neisius.de/fusor/index_E.html

She has built a working 'fusor' and has pictures of the same in operation...

http://www.diane-neisius.de/index.html

The page shows the proper layout of the anode & cathode, the layout, etc.

This is fucking insane, I love it