THE FUSOR REACTOR: Philo Farnsworth

Magnetic containment never reached this degree of success. Farnsworth’s system was compact, simple, elegant, and inexpensive. He solved the particle confinement and energy conversion problems in one simple design. On October 8, 1960, the Mark I Fusor produced a steady-state neutron count when deuterium was admitted into the device with very low power application. This meant that fusion was happening. What Farnsworth sought in these first tests lay in the control of fusion reactions under increasing power application. The self-sustaining reaction would be gradually approached in steps. Farnsworth established and charted increasing neutron counts with increasing application of electrostatic power. His methodic experimental method was necessary in the uncharted fusion territory. He repeatedly tackled the possibility of a “runaway” reaction, designing newer electron restraining guns to prevent this horror. It is suggested that the reader obtain and study copies of the Fusor patent for further understanding of this design aspect.


Farnsworth had to learn the operating parameters of a practical fusion reactor. Being a brilliant mathematician, his theoretical work was published along with the design patents. He established several criteria for testing the reality of achieving nuclear fusion in his system. The entire assembly was submerged in oil and was confined behind thick lead-concrete walls. The experiment took on a decidedly ominous tone after this procedure reconfigured the system. The entire Fusor reactor occupied the volume of a very small lecture hall. This volume included the power sources, tanks, shields, and monitoring devices. It was a rare miniature in the fusion art.

Dr. Farnsworth measured neutrons as an indicator of the fusion reaction occurring within the sphere. With deuterium gas in the Mark II-Model 2 Fusor a count exceeding 50 Mega neutrons per second was recorded. This device eventually produced 1.3 Giga neutrons per second in a sustained reaction for more than one minute. These reactions were stable, completely under the operator’s control, and could be duplicated on command.

On October 5, 1965 the Fusor Mark II-Model 6 was tested. A reconfigured, high precision ion gun arrangement produced 1 Giga neutrons per second, a world-record in the art. On December 28, 1965 tritium was admitted into the test chamber, producing 2.6 Giga neutrons per second. Higher voltages produced greater neutron counts. With a mixture of tritium and deuterium Dr. Farnsworth’s team measured and recorded 6.2 Giga neutrons per second.

The Mark III Fusor produced startling high records in quick succession. By the end of 1965 the team was routinely measuring 15.5 Giga neutrons per second. It must be remembered that this Fusor was yet the size of a softball. A Fusor having a diameter of just one meter would permit greater ignition power for a smaller time period, while multiplying its output power volumetrically. A Fusor could be built to any size, as power was required. Dr. Farnsworth reported that his team achieved a self-sustaining reaction on several occasions, and could repeat the effect. The thunderous vibrations of the Fusor are well reported by those who worked with Farnsworth. Many laboratory workers saw the brilliant white light of the Fusor in its early test runs … right through the metallic shielding!

Dr. Farnsworth once invited a few individuals to watch a test-run of this feat one evening. As power was applied to the Fusor the neutron-reading meter achieved a steady threshold and there remained. Only a slight additional increment of power was applied. Then the needle went off the scale and stayed fixed. The room thundered. The light released behind the shield would have instantly and permanently blinded anyone. Although the ignition power was completely removed, the needle remained off-scale in excess of thirty seconds as the fusion reaction sustained itself. Controlled self-sustaining nuclear fusion of tritium nuclei was historically achieved in 1965.

Success had come. The patent record shows that Farnsworth finally achieved that goal in 1965. The upscaled Mark IV would have completely cornered the electric utility market for ITT. Large Fusor systems could be set up everywhere. The Fusor System proved successful throughout its forgotten seven-year research history. The establishment of Fusor power stations would have been more than cost-effective for ITT. It would have made them trillions the world over. Fusor reactors were simple to build, maintain, and operate. Dr. Farnsworth and his team had computed each company cost to the penny! Therefore, who called ITT to stop production?


With the announcement of these final achievements, Farnsworth was met by a totally unexpected and contradictory turn of events. ITT had been gradually absorbing the entire Fusor project throughout the few record-making years. All related patents were assigned to ITT even as Dr. Farnsworth’s achievements arrived in successive steps. Suddenly ITT was “not interested” in the Fusor System.

It is both curious and contradictory that, while steady progress was being achieved at minimal cost, ITT was already planning to drop the Fusor project completely. Influenced by powerful professionally hired “lobbyists”, executive board members were urging the eradication of the project. During this strange time, certain Wall Street analysts were publishing their “concerns” for ITT and its absorption of the Farnsworth subsidiary as a “terrible mistake”. Farnsworth himself was made the direct focus of every corporate death word thereafter. Hired to assassinate the project and the project leader by yet unknown outside agencies, ITT folded up like wet cardboard under the pressure.

This complete contradiction is all too conspicuous, a familiar pattern in American technology. Outlandish accusations against ITT remain in the indelible historic record. Newspapers from the time period, journals, and other publications show the campaign. Nevertheless, and equally indelible, are the patents and periodical records which Farnsworth has left to us on controlled fusion. Who had “spoken” to ITT, dissuading them from further development of the Fusor reactor? The AEC was mounting the uranium fission race and the “anti-fusion” race simultaneously, using every tactic to achieve total dominance of the energy field.

A large reception at the Waldorf was astir with executive unrest concerning the Farnsworth research project. While dressing for the dinner that evening, Farnsworth suffered a stroke. He was thereafter suddenly “relieved” of his research project, now on the basis of his “now failing health”.