My Fusor in Action
BackgroundThe best website I have found so far for IEC fusion is Fusor.net. If you are interested, join the forum and peruse. This site is where I got most of my information. Inertial Electrostatic Confinement Fusion was inventer by Philo T. Farnsworth. He also invented the modern CRT televeision. An overly simplified explanation follows: A fusor consists of a single grid inside a grouded vacuum chamber. The grid is negatively biased at several tens of kilovolts. Neutral deuterium molecules in the chamber are accelerated toward the negative well. Most of the molecules miss the grid (since it is mostly empty) and continue in to the center of the grid. There they have a certain possibility of colliding with other molecules and a certain chance that such collisions are energetic enough to overcome the coulomb potential and fuse together. The probability of fusion is proportional to voltage and inversely proportional to pressure. An increase in voltage results in a more energetic collision, and a decrease in pressure reduces the likelihood that a (less energetic) collision outside the grid will occur. Several advances have been made in this field. None have proven successful at break even fusion. One major source of loss is the ion bombardment of the grid. Every time that a D2 molecule collides with the grid, a unit charge is lost and heat energy is transferred to the grid. With enough current, this problem can be overcome but it comes with a significant loss in efficiency. Also, the grid may become too hot and melt. On a more general note, here is a Prezi on fusion power. Unfortunately, I don’t include much info on my presentation. I prefer to just talk it out.
Making a Fusor
I have to warn you about a project as extensive as this. Less than fifty people have succeeded in making fusion in their basements since Richard Hull’s epic first Fusor in the late 90s. If you aren’t careful and/or are impatient, this project could run you into the tens of thousands of dollars… You have been warned.
Typical Fusor Parameters
I typical fusor operates in the 20 KV to 50 KV range and between 5 and 50 mA. Generally a variable (voltage and current) supply is used but not necessary. Vacuum pressures of less than 10 milliTorr are recommended. Deuterium gas is available to the amateur in either bottled gas form or heavy water. Heavy water needs to be electrolized and dried before entering the chamber. Of course you will have to have some means of viewing and detecting the fusion.
A common improvement to the original fusor is the addition of a second grid. There has been a significant amount of research (amateur, private, and governmental) into the modification of the basic fusor to eliminate the grid issues. One such method is the use of magnetic mirrors to form a virtual cathode called a polywell. It was created by Dr. Robert Bussard under contract with the U.S. Navy.