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- Q: I wonder why radiation concerns are not mentioned in published
articles about the period when when ITT and Dr. F were working together.
The pictures show no radiation suits on the experimentors, no gadgetry
around which would be related to that.
- A: These people had a special shielded "cave" to work in.
The most productive fusors were also tested in a shielded "pit." No
radiation suits were needed because the tests were run at relatively
low power levels, and the personnel was isolated from the Device Under
Test by either the "cave" or the "pit."
- Q. What are the by-products of a fusion reactor?
- A: The combination of hydrogen atoms produces helium, an inert gas;
the mass of the helium atoms being less than the mass of the combinant
hydrogren atoms, the difference is given off as energy according to
Einstein's famous formual E=MC2. The energy is transferred to neutrons
which are thrown out of the reaction at different rates, and also protons.
There is also some tritium produced, which has radioactive half life
of twelve years.
- Q: How did they solve
the problem of introducing new fuel into the chamber?
- A: They didn't, really, so far as we know, although there are some
tantalizing stories about " startling and unexplained" events
in the Fusor lab that suggest the problem may have solved itself on
- Q: What does the fusor use for fuel?
- A: Fusors usually run on deuterium gas. More advanced experiments
can use tritium, which is a radioactive isotope of hydrogen. As such
tritium is highly regulated an unavailable for unsanctioned fusion experiments.
In the future a fusor could run on He3 or Boron.
- Q: I thought temps in the 200,000 degree range were required to cause
fusion, how did DR. F manage this with less?
- A: Actually, the plasma within the fusor can reach at temperatures
in the 20- 400 million degree range, depending on the fuel used. That
such temperatures can be reached, and sustained for periods of several
minutes, without destroying the fusor vessel is the magic of the "poissor,"
Farnsworth's name for the sheath of electrostatic shields that form
within the fusor.
Q:Why didn't BYU continue his work after Farnsworth passed away?
- A: Philo Farnsworth left ITT and relocated to Salt Lake in 1967 with
the intention of continuing his fusion research, but a series of unfortunate
business decisions conspired against his work and, ultimately, his life.
At least one operative Fusor was given to BYU, but students and professors
there could not continue work without Dr. Farnsworth hinmself. Farnsworth
was a unique individual, a gifted scientist endowed with special insights
into the inner workings of the atom - insights that he was at times
unable to convey to his colleagues. a special man . Without his guidance
the work ground to a halt.
- Q: Do you need a patent to build one of these things?
- A: The ITT Corporation suspended all work on fusors in 1968, after
the Atomic Energy Commission's fusion department refused to provide
any funding. The patents that Philo Farnsworth while employed by ITT
expired in the mid-1980s, and are now part of the public domain, but
the patents are regarded as "incomplete" and do not disclose a fully
functional (i.e. net-energy generating) fusion device.
Likewise, the patent for the "Hirsch-Meeks" variation of the Farnsworth
Fusor, which is the Fusor that the members of this site are experimenting
with, also expired in the mid-1980s. Patents are granted for a non-renewable,
17-year term, after which the art disclosed therein enters the public
domain. The Hirsch-Meeks patent was issued in 1968, and so would have
expired in 1985. Consequently, none of the art being experimented
with here is under any patent priority.
- Q: Why can't I find anything in the library about this subject ?
- A: There really is just not very much material available anywhere
on the subject of inertial electrostatic confinement fusion. Most of
the writing on the subject has focused on the magnetic confinement schemes,
primarily a breed of machine called the "Tokamak" which sponged up the
majority of the interest and funding for fusion research for the last
35 years. You might try looking for a book called "Fusion - The Search
for Endless Energy" by Robin Herman. Try an out of print bookseller
- Q: Why is neutron flux dangerous ?
- A: Humans are in large proportion plain old water. If a neutron encounters
and sticks to an ordinary water molecule it forms deuterium and releases
a burst of gamma rays that causes genetic mutation and sometimes cell
death. A neutron flux is more than one neutron. The larger the number
of neutrons that hit you the more damage is done. A flux greater than
10e12 is a fatal exposure in the long term. A flux in the 10e13 range
is a death in a week. If you want an accurate representation of what
transmurasion (radiation) sickness looks like rent the movie Fat Man
and Little Boy with John Cusak and Paul Newman. A naked core accident
is portrayed in vivid detail...... not for kids. An accident like that
is in the 10^20 neutron range. (Answer by Larry Liens)
- Q. What is "Star Mode" ?
- This question was submitted by Alex Sloat (07/11/2002). We turn to
Richard Hull for the definitive answer and an illustration from his
is a visual signature of good clean operation of a fusor. It heralds
a major, initial success in the construction of the basic device.
In the fusor, good geometrical alignment of the inner grid structure
is important. A clean vacuum that is free of organic vapor and, hopefully,
water vapor is also desired. If these criteria are met, then the indicative
visual signature is referred to as "star mode". The appearance
to the eye is of a glowing ball of plasma within the center of the
inner grid with what appears to be multiple radiating, fine pencil
like rays streaming out of it through virtually every opening in the
inner grid. It is not only unmistakable and beautiful but shows that
most of the basic hurdles in fusor operation have been conquered.
This mode of operation is a virtual "must have" in a demo
fusor before moving on to a real neutron producing fusor with deuterium