Plasma Experiment Involving Magnetic Fields

[Shreya]

I want to perform an experiment to show that magnetic fields can control plasma. (Can even be a slight repulsion)
Please Suggest one.
I have no idea where I can obtain plasma - I have access to candle flame (though it's not a proper plasma) & fluorescent lights.
I have a permanent magnet (not a strong one), copper wire, cells.
Please be kind to suggest an experiment.

 

[mfb]

Found looking for "candle flame magnet"

Your permanent magnet won't lead to such a strong effect, but passing it close to the flame might still produce some visible result. Make sure to shield the flame from the movement or air or have a nonmagnetic control sample.

 

[Shreya]

Make sure to shield the flame from the movement or air or

How do I shield it?

 

[Shreya]

As far i have found,
The repulsion is due to :
1. The diamagnetic effect of wax & gas
2. Attraction of oxygen
3. Ions in flame
When a brought the magnet really close - 2 to 3 millimeter, I saw a slight repulsion of the flame.
In this case can I ignore the first 2 effects ie diamagnetic effect of wax & attraction of oxygen.

but passing it close to the flame might still produce some visible result

 

[mfb]

How do I shield it?

Anything that blocks the motion of air. Preferentially something that's not flammable. Aluminium foil?

But it sounds like the effect was already notable with a slower motion of the magnet where this is less of a concern. Repeating the experiment with something that's not magnetized would still be interesting.

 

[Limebat]

How do I shield it?

Try something that is nonferrous (does not block the magnet). Perhaps you can use a dollar store mason jar / other glassware to test your idea out.

Hmm. But maybe that would not be close enough from the magnet to flame to actually observe anything (the glass jar is in the way). After all, these are assumptively weak magnets. Well. Only one way to find out :D.

*Not entirely sure if you have a Harbor Freights nearby, but you can get some strong shop magnets with dozens of pounds of pull from them for a decent price.*

 

[Bandersnatch]

Just to make clear the meaning behind what people are talking about with the shielding - it's about proper experiment design.
To make sure any experiment whatsoever shows what it is purported to show, one needs to 1) eliminate all confounding effects, 2) do a control run.

Shielding the flame is about 1) - you should put a screen (like the aforementioned aluminium foil, or a pane of glass) between the flame and the magnet, to make sure the deflection of the flame is not e.g due to proximity of an object changing the air flow, or its motion disturbing the air.
2) is about using a 'placebo', i.e. you repeat the same experiment with a non-magnetic block of similar size and shape. Should this also show deflection, you'll know there's some other effect that you did not eliminate in step 1), and it's very likely not due to magnetism.

Ideally, one would repeat the whole process several times. And make the tests blindly (not knowing whether one is testing the magnet or the non-magnet).

 

[Shreya]

Just to make clear the meaning behind what people are talking about with the shielding - it's about proper experiment design.
To make sure any experiment whatsoever shows what it is purported to show, one needs to 1) eliminate all confounding effects, 2) do a control run
Ideally, one would repeat the whole process several times. And make the tests blindly (not knowing whether one is testing the magnet or the non-magnet).

Thanks Bandersnatch, for explaining the whole sheiding process. It really helped me.

Only one way to find out :D

Indeed, Great Idea!I will try that, Limebat

notable with a slower motion of the magnet where this is less of a concern

Mfb, I actually observed the repulsion as a slight (I mean really slight) curving of the flame's shape when the magnet was brought really close to it. So, can I conclude that this effect was due to magnetic repulsion of the ions in the atom or is it because of other effects (like O2 attracted to magnet, etc...)?
BTW, just to confirm, if candle flame is not entirely a plasma, then does it contain enough ions to show the repulsive effect?
And is there any other diy plasma experiment I can do (with the aim of showing that magnets can control plasma)?
The whole purpose of these experiments are to really get a gist of what's going on in the tokamak nuclear fusion reactor!

 

[mfb]

First repeat the test with something similar that doesn't have a magnetic field.
Distinguishing between different effects that happen at the same time will be difficult, but at least you can rule out all non-magnetic effects that way.

We call things a plasma as soon as there are enough ions and electrons to dominate the behavior of the medium, it's not needed to ionize everything.

The whole purpose of these experiments are to really get a gist of what's going on in the tokamak nuclear fusion reactor!

That would have been useful information in post 1. The magnet and candle experiment is a nice demonstration that a magnetic field can have an effect, but it's nothing like the concept of a tokamak.

 

[Shreya]

First repeat the test with something similar that doesn't have a magnetic field.
Distinguishing between different effects that happen at the same time will be difficult, but at least you can rule out all non-magnetic effects that way.

Yes! I surely will try that.

it's nothing like the concept of a tokamak

Yes , indeed. But, I think it can be used to
This was the result of my first experiment (one I did before posting this Question). It was done in a dark room with all windows closed and almost no air movements. You can see the bending of flame in this image, the same result was seen multiple times.
I tried the same with a steel blade too (though not of the same size as the magnet) and I did not observe any effect such as this.
I will try this experiment again incorporating the suggestion I got here.