Creating Plasma for demonstrations

[mclrn227]

Hello! I'm new here and I just wanted to ask one question. What do you guys think about creating plasma with a grape, a glass, and a microwave? You can find videos of this all around but I was curious regarding the safety of this experiment. You cut a grape into 4 section and place 2 sections side by side in a microwave with a glass over the top of it. After about 5 seconds the charge between the two, very water saturated, masses creates a plasma ball that is captured in the glass. Its a very neat idea but I was just mainly concerned with the overall safety. What do you all think? Could it really damage a microwave after only 10 seconds? I'd love to use this on Monday.

[insane_alien]

it should be pretty safe. just don't run it for too long. maybe 30 seconds maximum. keep a hand near the off switch incase you see anything obviously abnormal.

 

i take it your a teacher or something since you said 'use it on monday'

 

just make sure its not the staff microwave, they might grumble if you break it.

[[Tycho?]]

It would be best to use a microwave that you could do without.

 

But doing it for such a short time should be ok, once you see it glowing dont let it go too much longer. You could try to get in contact with those people that made the videos (even posting in the comments of the video if its on youtube could yield some results).

[Gypsy Cake]

I went and watched a couple of videos. The people are not gonna advise you to do it.

 

Though it is pretty amazing and I'm gonna do it at some point.

[Cap'n Refsmmat]

I've seen it done. Nothing exploded, but it was done for only a few seconds, and smoke started coming out even by then. No permanent damage done though, I think.

[CPL.Luke]

I did a project on this where I routinely burned metals in a standard microwave every day for months. The worst thing that can happen is some burn marks in the microwave.

 

although if you run it for two long with glass around, or if there isn' a glass plate to insulate the metal from the microwave cage, oyu can cause damage.

 

the worst problem I ever encounterred was glass melting in the microwave, in the name of science my partner and I continued to run the experiment. after several seconds the glass got to be white hot (once the glass begins to heat up it becomes a conductor, and from there the microwaves will heat it directly), and proceeded to melt a dent into the microwave, permanently killing the microwave.

 

there were also some close calls when the metal sparked to the microwave cae, while the cage is grounded and somewhat rotects the magnetron from being shocked to death, this isn't guarenteed.

 

my suggestion would be to get a glass bottle (like an IBC rootbeer one (12-20 oz size) and place a couple of paperclips inside of it, the bottle will capture the plasma temporarily and give you a nice light show, this will work until the bottle cracks/shatters which will then require some clean-up, however the microwave shouldn't recieve any damage, and as long as you watch for melting glass you'll be fine.

 

 

alternatively 2 halves of a grape placed right next to each other will work quite well.