Most people are familiar with 3 states of matter being solid, liquid, and gas but a lot of people are not familiar with the 4th. The fourth state of matter is plasma defined as an ionized gaseous mixture consisting of highly charged positive ions and free electrons (negative charge) that result in little or no electric charge. The amount of energy in each state of matter increases as you progress. Plasma is typically created at low pressures or at very high temperatures. Believe it or not plasma is the most common form of matter in the universe. [taken from definition, wiki, and general knowledge]
Examples of plasma are neon signs, CFL bulbs, lightning strikes and probably what I’m most interested in Fusion (the sun). Uses of plasma can be found in the manufacturing of electronic components such as semiconductors, metal plating of glass/silicon/etc, mineral extraction, ion propulsion and one day a very clean and efficient energy source.
Plasma conducts electricity and can be manipulated with a magnetic field. These properties are at the core of what I want to accomplish with the plasma chamber.
Experiments for the chamber
Small scale plasma accelerator
Plasma sputter plating of metals on to glass
Ion drive simulation
Magnetic containment fields
Effect of plasma being pushed through a coil
Plasma being formed with various gases and/or particle filled gases
Custom waveguide antennas to concentrate energy for various applications
Effect of electricity being applied across plasma
Effect of shooting electrons through plasma
Find a way to manipulate power and frequency of RF signal
There’s a lot of in-depth overview random basic RF information. With that said I don’t mind getting into the details because this information will help keep me safe while I perform experiments in the future.
A magnetron generates large amounts of RF energy and emits that energy as an antenna pumped through a wave guide. Most microwaves transmit/operate at 2.45GHz. Unless something is wrong with your microwave or you have taken it apart like I will be doing the RF energy, 2.45GHz, transmission is contained within your microwave using a Faraday cage. On your right is an example of a crude Faraday cage. While crude this mesh size would probably be safe to use for 2.4GHz.
A microwave oven works by pumping a lot of RF energy into an enclosure where it bombards the molecules of food or whatever you have put in your microwave. This RF energy is not in a straight line but is guided through a wave guide then and then bounced off the metal walls of the inside of the microwave. The RF energy then vibrates the molecules which creates heat. This is like when you rub your hands together (friction) and they get warm but on a molecular level. What I don’t want is my molecules to get vibrated.
The Faraday cage is made up of the mesh in the window as well as the metal case which share a chassis ground. The mesh in the window blocks the the RF because the mesh size is smaller than the wavelength of 2.45GHz/2450MHz/2450000000Hz. If the mesh size is lower than the nominal wavelength the mesh should be effective. Look at the list below to see what the wavelengths in size is. For this project I plan on using the RF blocking glass that I obtained samples of from Viracon which is way different than a Faraday cage but same principle. You can see the article I linked to but I also included an image here.
Full Wavelength = 12.23643cm/122.3643mm = 0.1223643m
Half Wavelength = 6.118215cm/61.18215mm
Quarter Wavelength = 3.0591cm/30.591075mm
You can calculate the wavelength using the formula 𝜆 = c/𝑓 or 0.1223640816326531 = 299792000/2450000000
𝑓 = frequency in hz, c = speed of light in mps 299792000, 𝜆 = Wavelength in meters
N5JLC is my math right?
So basically if my mesh is smaller than 30mm, if I’m right, I should be protected. I plan to use the glass but if needed I will use hardware cloth.
In order to protect myself and nearby electronics I want to monitor external and internal RF to ensure there is not leakage. RF Meters in general are not that difficult to build but ones that cover the 2.4GHz range require a bit more than a germanium diode and multimeter. In short you’ll probably see a 2.4GHz RF Meter project coming soon. Below are some RF Meter projects but if you know of any please let me know.
One step closer to the next round of plasma chamber experiments!! I got samples of RF blocking glass panels in from Viracon. This stuff is really cool. Check out the video below for how it works. The next step will be running some tests, prepping a microwave and building an RF meter.