Fusor Forums

With a magnetron from a microwave oven. What would a simple setup look like for deuterium gas at 1-10 Pa?

We recommend against using magnetrons from ovens unless you are expert in microwave technology. Unlike radio waves from a transmitter the magnetron throws all its energy in a directed beam. Reflections, VSWR mismatch issues and failure to observe strict precautions can have an eye or an organ cooked by a misdirected or reflected beam or blow up the maggie, itself.

If you are not very careful you can create a life changing event.

Two of our most stringent and strong admonitions.

1. Do not play or experiment with x-ray tubes or powerful oven magnetrons
2. Do not open or work with naked, controlled radioactive materials.

Richard Hull

Sven
look at Richards reply
but you can put a tube of your favourite gas in an ordinary microwave oven and see the result

for a start take an ordinary incandescant bulb that has a blown filament and put it in an ordinary microwave oven and observe the argon plasma

Ordinary bulbs are back filled with argon to stop the tungsten filament evaporating.
After doing this consider your quest done!!

John Futter wrote:Sven
look at Richards reply
but you can put a tube of your favourite gas in an ordinary microwave oven and see the result

How about this for a setup: take a vial or ampoule with two internal plate electrodes melted into the glass. Fill with D2 at the pressure I choose. Microwave in an intact MW-oven until there is a plasma. Turn off microwave oven. And immediately (can be programmed with relays perhaps) turn on the high voltage between the electrode plates and observe what happens.

But how do you safely lead two wires into the MW-oven? Drill two 2 mm holes in the internal metal cage? Now, can the wires act as antennas for microwaves and transmit them out of the MW-oven? Let's say you have two relays immediately outside the metal cage, and that those two relays are closed during the microwave phase, so to speak?

This has become a rather ridiculous thread. Folks in the know understand why this will not effectively do anything of value, much less, do any fusion at all. What's more, the idea would fail on the face of it. I fear that my usual Ben Franklin quote, "Let the experiment be done!", might result in Sven's untimely death or permanent injury so I will not recommend that path. That quote is usually reserved for those showing up here with grandiose ideas involving extreme time and expense to prove or disprove. They have ideas, but no verve or will to do.

Dangerous experiments are not to be recommended, commented on or condoned. Doing well-guided, well-trodden paths to successful amateur fusion are dangerous enough without rather hair-brained ideas involving 1 kilowatt microwave oven experiments where the very best result might be the destruction of the family's microwave oven.

Richard Hull

Richard Hull wrote:We recommend against using magnetrons from ovens

Some of the stuff people have done and put on YouTube is mind boggling as regards safety! Search for "What microwave oven is capable. Generated plasma." or "Magnetron #6 - Irradiating A Vacuum Jar" or "Dangerous Magnetron from Microwave Oven 1".

John Futter wrote:Sven
for a start take an ordinary incandescant bulb that has a blown filament and put it in an ordinary microwave oven and observe the argon plasma

Apologies for reviving a dead thread, but after reading this I was quite interested in what the temperatures inside the plasma will be. Do you have any ideas?

Did you ever consider reading the FAQs!!

viewtopic.php?f=42&t=10424

Temperatures as you know them........Plasmas are ice cold for the most part.

As physicists evaluated them.... millions and billions of kelvins

READ...READ...READ

Richard Hull

With all due respect, what I meant to say was that I was interested in whether or not anyone had actually taken a direct, relatively precise measurement of the plasma particle energies in a (specifically) microwaved lightbulb (even though I'm not sure how someone would go about doing this).

Assuming an absolutely clear light bulb and assuming you knew what gases were contained, a custom designed slit in an ocean optics or similar PC compatible spectrometer might be able to show doppler broadening of certain spectral lines to determine the range of energies in the gas. The microwave door would have to be open to give a clean light path to the spectrometer. It might involve a small telescope that would allow some distance from the microwave radiation. I can't imagine much real span on the broadening. (low average energies/plasma temp)

Certainly not worth the effort unless you already had the spectrometer.

Richard Hull

About that Doppler broadening of spectral lines, I ran some numbers Friday night but decided to hold off on posting them.
These are unreviewed!

Take, for example, the blue line of singly-ionized argon at 488 nm. Called 4880 Å when us oldsters were growing up.
At 300 K (room temperature), the thermal motion averages 0.026 eV per atom. RMS velocity is 508 m/s (293 m/s per axis, comparable to the speed of sound), and the FWHM linewidth from Doppler is 0.0007 nm.
At 10,000 K (0.86 eV per atom) it's 0.0039 nm.
At 100,000 K the kT energy reaches 8.6 whole eV, RMS velocity is about 9 km/s, and spectral linewidth due to Doppler is 0.012 nm.
Don't forget, we are talking about lightbulbs in MWO's, not fusors.

Ocean Optics USB4000 UV-VIS spectrometer normal optical resolution seems to be 1.5 to 2.3 nm FWHM. I saw somewhere that with a "plus" model, a resolution of 0.02 nm was attainable, but I think that needs more than just a narrow slit.