Here at last is the often quoted but not yet published paper by Don Gay. Here Don explains what goes on inside the Bussard Fusion Reactor. As is often the case the best explanations are the hardest to find, so Don has kindly allowed it to be published here. The explanation Don offers is really quite to the point and is done with terms most all of us can understand. This brief, but on point paper will greatly help anyone trying to grasp what Dr. Bussard has come up with. Please note that the text proper includes a notice that it would be preferable if you would ask for a copy of the pdf rather than cut and paste this article. That way the chances that someone searching for the paper will find many links for the pdf files rather than have to hunt deeply for a text. With many thanks to Don, it follows:


The Bussard Fusion Concept

By Don Gay

© 1993-2007 All Rights Reserved. Republished by Permission. © 2007 All Rights Reserved, (At some risk to this site and other sites that post it due to Google’s ranking program that ranks sites down when the robot sees duplicated material, please link rather than copy and paste! That way the article will be ranked higher making it easier for more people to see. I have a pdf of the paper that I can send if you would rather serve the paper from your site. Please email for a copy.)


This white paper provides an overview of an alternative energy source based on an inexpensive and practically inexhaustible fuel that offers an opportunity to relieve the United States’ dependence on foreign oil.

Description of the Concept:

Carbon 12 is a stable element consisting of a nucleus with six protons and six neutrons. If enough energy could be put into that nucleus, it would break apart or fission and would produce energy without the release of any radioactivity (energetic neutrons). But for it to be of any value, the amount of energy put in must be less than the amount of energy that comes out. This concept offers that potential.

The key to creating a highly energetic Carbon 12 nucleus is to fuse a Boron 11 nucleus with a proton. Boron is a very common element; it is the 10th most common element in seawater. Boron is found in two states: Boron 10 and Boron 11 with over 80% being Boron 11. Boron 11’s nucleus is composed of six neutrons and five protons. When a proton hits a Boron 11 nucleus with sufficient energy, fusion occurs and produces a very energetic Carbon 12 nucleus.

By definition, when Boron 11 is in an ionized state, its negatively charged valence electrons have been stripped away. The result is a very positively charged nucleus due to its five protons with no counteracting negative charge. It electrically repels any protons because of the like positive charge. At the same time, if the proton can be forced to come within a close distance of the nucleus – approximately the radius of the nucleus – the stronger nuclear attraction will pull the proton into the nucleus overcoming the weaker electrical repulsion known as the coulomb barrier. This is accomplished by getting the energy level or velocity of the protons to a sufficiently high state.

This concept is unique in the way that it accelerates the protons to a sufficiently high velocity. It creates an extremely negatively charged region in the center of a vacuum. The positively charged protons are then electrically attracted to this region and reach the velocity required for fusion.

This negatively charged region is created by first generating a vacuum. For the sake of discussion, consider the vacuum is in a hollow sphere made of stainless steel. Vacuums are measured by fractions of atmospheric pressure. Standard atmospheric pressure is called 1 torr. Ten to the minus 1 torr (10-1) is one-tenth atmospheric pressure. Ten to the minus 2 torr (10-2) is one-hundredth of atmospheric pressure and so forth. The vacuum required for this concept is between 10-5 and 10-6 torr. (Latest research indicates that 10-3 torr will work.) This is readily achievable with standard pump technology.

Once the vacuum is achieved, six electron guns, conceptually similar to those in vacuum tube projection television sets or like the old computer monitors only much more powerful, are arranged around the outside surface of the sphere as three diametrically opposed pairs. When these guns are fired, electrons stream toward the center of the sphere but are electrically repulsed by the electrons from the correspondingly opposed gun.

If not confined to the center of the sphere, the electrons would simply escape. But they are confined by a strong magnetic field imposed by electromagnets also mounted around the surface of the sphere. The result of the electron guns operating in concert with the magnetic field is to produce a concentrated region in the center of the sphere that is highly negatively charged due to this concentration of confined electrons. This part of the concept has been experimentally demonstrated and proven. However, some electrons can escape and that is the primary determinant in reaching breakeven. It is also the most critical part of the concept.

Minimizing the amount of electrons that can escape requires strong electromagnetic fields. These fields need very high electrical currents that generate large amounts of heat. This means that active cooling must be used. That takes space and basically establishes the minimum size of the sphere in order to fit the cooling system into the electromagnets.

The next step in the process is to insert Boron 11 and protons into the sphere so that fusion can occur. This can be done with Di-Borane gas, which is commercially available in pressure bottles. Di-Borane gas is comprised of two Boron and six Hydrogen atoms. It has a boiling point of -76 degrees F. Through injection into the sphere, this gas ionizes, losing its electrons, and because it is weakly bonded, separates into its constituents of two Boron and six Hydrogen nuclei. Keep in mind that a Hydrogen nucleus is simply a proton. Because of the positive charge on the protons and Boron, both are attracted to the strongly, negatively charged center of the sphere.

The Boron nuclei and protons accelerate to the center of the sphere and, unless fusion occurs, will continue through the region. They will then slow down toward the inner surface of the sphere and will turn around and will start another pass through the negatively charged region. This region is called the “potential well” or “core.” Many passes, perhaps a thousand or more, through the core will occur before a proton and a Boron nucleus meet. When they do, the kinetic energy of these two particles is sufficiently high to overcome the coulomb barrier and the proton is sucked into the Boron nucleus by the strong, nuclear force. When that happens, the Boron 11 nucleus becomes a highly energized Carbon 12 nucleus. The amount of energy in the nucleus is so great that it almost immediately breaks apart, or fissions into a Helium nucleus and a Beryllium nucleus.

Shortly thereafter, the Beryllium nucleus fissions into two more Helium nuclei. The result of this process is three Helium nuclei each having almost three million electron volts of energy (and the production of some X-rays). No neutrons are produced and this is a great advantage. Energetic neutrons cannot be controlled by magnetic or electric fields because they have a neutral electric charge. So they are like tiny bullets that can have devastating consequences. Consequently, this process is not radioactive and represents no hazard to people or the environment. The fission process and energy levels are well characterized and proven.

The next step is to extract the energy that is produced. This is accomplished by means of a positively charged electrical grid placed around the inner surface of the sphere. It is charged to somewhat less than the corresponding voltage level of the highly charged and energetic Helium nuclei. As these nuclei approach a similarly charged grid, the grid’s electrical field slows them. This transfer of kinetic energy into potential energy forces electrons from the grid. In other word, electricity flows. This direct conversion to electricity is one of the benefits of this concept and why it is so efficient (about 95%), compared with conventional nuclear reactors that extract energy by heating water to steam for driving turbines.


11 Comments so far

  1. M. Simon on August 21, 2007 10:04 PM

    The magnetic field does not trap the electrons. The positively charged grid does that.

    The magnetic field shields the grid and causes a density gradient in the electrons. It allows particle density to be higher in the reaction space than the rest of the machine.

    What goes on in the machine is subtle.

  2. Joe Strout on August 23, 2007 8:40 AM

    I’d like a copy of the PDF mentioned. How can I get it, or how can I get in touch with Don Gay?

  3. Tony Belding on August 23, 2007 12:11 PM

    M. Simon. . . The positively charged grid that Don mentioned does *not* trap the electrons. That grid is only used for extracting energy from the helium nuclei after fusion has already occurred. In a test reactor (as opposed to a power plant), you wouldn’t even need any grid.

    You may have confused the charged grid with the grids used in earlier IEC reactor designs. They used a charged grid to maintain the electrostatic potential in the center for the reactor. The problem, of course, was that ions kept impacting the grid, which meant energy was lost and most likely the grid was melted or eroded away. The breakthrough of Dr. Bussard’s “polywell” design lies in getting rid of that grid and replacing it with electrons trapped using magnetic fields. The whole grid collision problem is then removed.

  4. Kevin Klassen on August 23, 2007 2:35 PM

    Tony Belding, there are 2 different grids being discussed. The grid you mention is on the outside of the whole device for direct energy conversion.
    MSimon is correct, the magrid is the term used for the magnets and their casings that are used for confining the electrons. The magnetic field weakly traps electrons in the centre. The positive charge on the magrid keeps electrons that escape the centre recirculating back in. The magnetic field also keeps the electrons from crashing into the positively charged grid. All those forces work to create a device with a dense core of electrons without any grid. The area inside the magrid is equivalent to the area inside a traditional fusor, without the grid. Head over to for links to papers and diagrams that should make it more clear.

  5. Don Gay on October 20, 2007 8:20 PM

    I just noticed the comments above and want to correct one person’s statement. The positively charged electrical grid for extracting the energy does not confine the electrons. It is the field from the external electromagnets. The “core” or “well” has already been conclusively demonstrated without the internal electrical grid even being in place. Due to the volume of emails that I’ve received, I’m not able to respond to them as I would like. I would encourage those with an interest to watch for news from those doing the research as the project progresses. Thank you.

  6. Ronald Lee Townsend on November 15, 2007 10:39 PM

    “Through injection into the sphere, this gas ionizes…” What is the mechanism that causes the gas to ionize?

    “six electron guns…are arranged around the outside surface of the sphere as three diametrically opposed pairs. When these guns are fired, electrons stream toward the center of the sphere…” By what mechanism do the electrons “stream” toward the center of the shpere? In a CRT they stream toward the face of the tube because of a very large positive potential at the face of the tube.

  7. bluzki on October 10, 2010 4:21 PM

    Great site, figured out a few new things! Subscribed RSS for later, hope to see more updates like this one.

  8. TOEFL ibt on October 20, 2010 4:59 PM

    Already been browsing your articles for few days. Would like to leave a comment tell you I truly love your web blog. Many thanks!

  9. Christmas Friends on November 1, 2010 6:18 PM

    Me and my wife thoroughly enjoyed this article, we are sitting down right now to a cup of tea and talking with the laptop beside us. Just some questions: When did you get into blogging? How much is hosting per month? How much are you making per month? How many visitors do you usually get? Have you heard any big success stories with people blogging? Appreciated, we’ll be checking back but you can e-mail us aswell.

  10. nurse practitioner on November 8, 2010 10:41 AM

    Finally, an issue that I am passionate about. I have looked for information of this caliber for the last several hours. Your site is greatly appreciated.

  11. Haarentfernungen on November 29, 2010 8:15 PM

    I have been reading a lot on here the topic Don Gay’s | New Energy and Fuel inspired me, i have picked up some really great ideas. Thanks and i hope to see more soon.

Name (required)

Email (required)


Speak your mind