Microwaves

Microwaves don't really have anything to do with Ion thrusters, except that they have diodes in them.
Diodes are electrical components that only let electricity flow in one direction. I found out that I need them for my thruster when I tried to turn it on. At first I thought that it wasn't doing anything- the air didn't seem to be moving at all, although it was making a buzzing noise. Than I realized the air was just vibrating! It turns out that the electricity that was powering it was AC (alternating current- basically it quickly alternates between plus and minus). So it was working, but the air was just changing direction so fast that it never really had time to go anywhere.
     Luckily, there is one good way to turn AC into normal current (DC), and that is with a rectifier. A rectifier is made out of four diodes connected end to end. I actually have a small pre-made rectifier, but it is not nearly adequate for the required 12,000 volts. So I'm making my own!

But meanwhile, this is what I found inside the microwave:


This is the cooling fan. The part at the bottom is the high voltage motor.

This is the motor that turns the glass plate:

This is the light:

These switches detect if the door is open or closed:

This is a heat sensor; it will turn off the microwave if it gets to hot.

This is a huge capacitor. Capacitors are like short-term rechargeable batteries.

This is the transformer that supplies the high voltage required for the magnetron.

This is the main circuit board. It includes a controller chip, a beeper speaker (It beeps), two relays, a quarts timer, a seven segment display, and a small transformer. There are also a bunch of other components, including diodes, resistors, capacitors, and transistors.

This is the big diode. It's the one that I need for my thruster.

This circuit board controls the electricity coming in to the microwave.

There is also the magnetron, which I don't have a picture of right now, but I will add one soon.

How they work: More detail

The last article was more of an overview of an ion thruster. Now I'll tell you how they really work, at the molecular scale.
First, definitions:
    Ionization: "Ionization is the process by which an atom or a molecule acquires a negative or positive charge by gaining or losing electrons to form ions, often in conjunction with other chemical changes." ~Wikipedia, see sources, https://en.wikipedia.org/wiki/Ionization

    Plasma: Ionized (see above) gas.


In an ion thruster, the high voltage between the positive and negative electrodes (see previous post for the diagram) rips the electrons off the gas atoms (usually xenon, a gas similar in properties to neon), ionizing them. Gas that is ionized this way has a positive charge, since the electrons that were ripped off were negative. If something is charged it acts like a magnet, and that is exactly what the gas molecules do, pushing each other apart and causing the gas to expand.
Since magnetic fields can be used to move ions, electromagnets are used to direct and accelerate the plasma out the back of the thruster. This is also helped along by the fact that the backward electrode on the thruster is negative, and therefore attracts the positively ionized plasma (like magnets).

What is ion propulsion?

Ion thrusters are an efficient but slow form of propulsion, that could theoretically be used to travel extremely long distances in space.
They use very high voltage to ionize gas, basically turning it into a bunch of magnets. Since magnets attract and repel each other, electromagnets are used to direct and accelerate the ionized gas (plasma) out the back of the thruster. If the thruster is mounted on a spacecraft, this can be used to traverse extremely large distances at high speeds. Ion thrusters are very efficient because they take a very small amount of fuel to operate. Unfortunately, this efficiency is traded for fast acceleration, so it takes a long time for ion thrusters to get going fast, but when they do they could go very far.

How it works (Diagram)

The polarities are wrong in this picture, positive is really negative, and vice versa. (sorry)

https://www.youtube.com/watch?v=TVkioe3PJz0

Something like what I'm going to do

http://makezine.com/projects/ionic-thruster/

A simple ion thruster

Ion Propulsion video on YouTube