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found this interesting info in the P.T Farnsworth patent section

Posted: Sat Sep 29, 2007 1:41 pm
by JamesBroussard
is this true?'

While others have chronicled the life and times of P.T. Farnsworth, my interest lies in his inventions and patents. More specifically, how the design of those separate devices led up to the final development of the Fusor - the only fusion reactor ever designed and operated at better than break-even efficiency! Farnsworth's Fusor produced neutron counts measured in the billions-per-second. . No other fusion device built, even 30 years later can match this performance. It is unfortunate that Farnsworth died before perfecting the device into a commercial product, but that does not detract from his accomplishment in the least. That one man could conceive of and design a working fusion reactor is a phenomenal personal achievement. It would be nice if someone would build another working device.

"Fusor produced neutron counts measured in the billions-per-second."

Re: found this interesting info in the P.T Farnsworth patent section

Posted: Sat Sep 29, 2007 2:44 pm
by Jon Rosenstiel
No.

Re: found this interesting info in the P.T Farnsworth patent section

Posted: Sat Sep 29, 2007 4:17 pm
by JamesBroussard
okay thats what i thought lol...

Re: found this interesting info in the P.T Farnsworth patent section

Posted: Mon Oct 01, 2007 11:22 am
by Richard Hull
The apocryphal tales of Farnsworth's machines are many and varied.

There was no really significant neutron numbers in any of Farnsworth's fusors until they went over to using D-T in the 63-64 time frame. Not one person there could remember even the specific year they started using D-T, but they felt it was about the time Hirsch arrived on the scene. The team, itself never held a tritium license! Another lab and reseracher did have tritium in the same building and they used his site license.

The two camps/cliques within the pontiac street effort vied for neutron numbers, Farnsworth's ideas never produced decent numbers until he left the positive grid system and went over to ion guns. Ultimately, it would be Hirsch who came up with the highest figure of over a billion n/sec in the cave fusor using D-T near the end of the program in 1968.

Thus, Farnsworth, in his machines, never hit those numbers.

Richard Hull

Re: found this interesting info in the P.T Farnsworth patent section

Posted: Tue Oct 02, 2007 1:28 pm
by JamesBroussard
ahh thx richard, well my main interest was on the number recorded, 1x10-9
if true its the highest number of n/sec iv seen so far from iec devices, is this the highest recorded?

Re: found this interesting info in the P.T Farnsworth patent section

Posted: Tue Oct 02, 2007 5:24 pm
by Richard Hull
To my knowledge, yes.

I am sure Jon or Carl could equal that in their machines if they could use 50:50 D-T. That is where the numbers are in the Farnsworth effort, NOT in the fact they had such good devices!

Richard Hull

Re: found this interesting info in the P.T Farnsworth patent section

Posted: Tue Oct 02, 2007 6:30 pm
by MarkS
It'd be incredible to see the record broken by an amateur.

Re: found this interesting info in the P.T Farnsworth patent section

Posted: Wed Oct 03, 2007 9:32 am
by Richard Hull
Certainly, long, ago both the U of I and U of W fusor teams could have beat that record in their devices, but colleges no longer want to hazard using tritium in any, on campus, system. The new rule is NO RAD stuff on campus.

There was a time when colleges vied for their own reactors and made their own isotopes on site with small piles or swimming pool reactors. Nuclear engineering and nuclear physics departments and their respective curriculums blossomed. Almost all have withered on the vine since the 70's.

With litigious lawyers driving slighted students and frightened families, coupled with a modern day view of "everything is bad for you", no college is willing to introduce any suspect program or percieved hazard into their school. They realize that any student looking for a free ride or parents needing money will have a cadre of lawyers at the ready.

Many of those schools with nuclear programs in place since they first begged for them in the 50's, have, during the 80's, totally dropped the courses or so emasculated them that all work is now done on computers rather than in the radioisotope labs or reactor building on campus. The old labs are now normal class rooms and the reactor building is now an extra gymnasium.

Thus, Tritium is just not in the cards, even for high end acedemia in forward looking, physics research efforts. The rule is, "If you think you need tritium for your research, find something else to research."

Professors are not happy with the stuff either for they are would be the last guy in the finger pointing contest if something goes wrong and all of us have seen the modern day "cover you ass" mentality in acedemia.

I am the proud owner of an "in-house" created and printed nuclear program handbook for students at U of Pennsylvania in the late 60's. This was a lab type work book of about 100 pages.

The professor who wrote the manual glibbly notes that... "When the emergency nuclear alarm klaxon sounds in the reactor building, all students must immediately go outside to the designated nuclear emergency area and wait for the all clear siren."......" The alarm klaxon is loud, unmistakable and most offensive in nature. The "all clear" siren is a standard police siren."....."Do not just ask others if there is a real emergency or if this is a false alarm or test; all such alarms are always either tests or false alarms. Simply stop what you are doing and evacuate immediately"......"Our nuclear site licenses and AEC agreements for continued reactor use depend on all people immediately obeying the klaxon....just obey, get out, and wait"

Richard Hull

Re: found this interesting info in the P.T Farnsworth patent section

Posted: Thu Oct 11, 2007 2:41 am
by JamesBroussard
haha, "If you think you need tritium for your research, find something else to research.", to bad they would stifle the creativity of scholars wanting to use rad substances for research even because of the inherent danger... anyways, recently i had the privilege of talking to a nuclear reactor safety adviser on radiation (at least thats what he did if not the name of the job), and he let me in on a few good tips, protection from these high velocity particles, and seeing how water is the best protector (cheapest at least) thats what ill be using...

but i have a question is there an equations i can use to calculate amount/thickness of water i need for how many volts(or energy of the D-D reaction put into the neutron?)

also i know its hard to produce but what are the prospects of antimatter fusion if it was easier to obtain/produce (assuming this hasn't been brought up in the forums before, if so sry to bring it up again lol)

Re: found this interesting info in the P.T Farnsworth patent section

Posted: Thu Oct 11, 2007 8:48 am
by Hector
Another reason why UI and others don’t care to use D-T is that by knowing what the reaction rate of the D-D reactions are for there devices, they can quickly calculate what the reaction rate would be if they use D-T, thus forgoing the hazards of Tritium.

On another note, the problem I’ve always had with the Hirsch approach is that while it achieves a higher neutron count on the front end it does so by sacrificing reaction efficiency and thus the potential to achieve breakeven or above in the long term.

In my opinion Bussard and Farnsworth had it right, if you confine the electrons to the point of creating a deep potential well with them, the ions will fallow and you would have eliminated the primary loss mechanism of the electron confinement IEC devices, which are simply electron losses to the grounded outer spherical grid or wall member.

The Hirsch approach suffers from both electron losses and ion losses to both the positive and negative grid members, so its long term potential as an efficient breakeven device does not seem promising.

At the end this is only my opinion and nothing more.

Re: found this interesting info in the P.T Farnsworth patent section

Posted: Thu Oct 11, 2007 1:49 pm
by MSimon
Any one know how they manage to do nuclear medicine?

Re: found this interesting info in the P.T Farnsworth patent section

Posted: Thu Oct 11, 2007 3:29 pm
by Richard Hull
Assuming the question is not facetious..........

Nuclear medicine involves controlled short lived isotopes that are quite deliberately injected or ingested by the patent, whereby the procedural benefits would outweight any radiation side effects. These are often one pass events, as well.

The problems with tritium, radon and the like is the nature of dosing........, random, not desirable, unseen and unknown amounts, permanent burial of longer term isotopes within the body for 24-7 irradiation for years.

Nuclear medicine involves itself with intense radiation sources with ultra short half lives.

There is some evidence that horrid internal acute doses, (as often used in nuclear medicine), are not nearly as dreadful as moderate internal doses that go on for years on end.

Thus, nuclear medicine thrives.

Still..............Who knows where medicine will take us.....
In as few as 20-50 years from now nuclear medicine, as practiced today, may be viewed with as much horror as we currently view blood-letting in the 15th and 16th centuries.

Richard Hull

Re: found this interesting info in the P.T Farnsworth patent section

Posted: Thu Oct 11, 2007 3:40 pm
by MSimon
I was serious.

Thanks for the reply.

There is some evidence that moderate doses of radiation actually strengthens the immune system. I'll see if I can find an article.

Re: found this interesting info in the P.T Farnsworth patent section

Posted: Thu Oct 11, 2007 3:48 pm
by Richard Hull
This is referred to as "Hormesis" generating a "Hormetic" effect.

This has been discussed at some length on many ocassions in these forums. A simple search, mostly within the radiation forum should pull up any number of papers.

In general only high energy gamma radiation might be considered hormetic as it penetrates thoroughly. Hormetic continuous doses are thought to not exceed 2-10 times background readings. There is a proposed curve that notes a turn around from hormetic to pathological. All of this is just proposed and speculation, there is no medical authority behind this, only anecdotal pointers. Medical authority is firmly and safely entrenched behind ALARA. (As Low As Reasonably Attainable)

Richard Hull

Re: found this interesting info in the P.T Farnsworth patent section

Posted: Thu Oct 11, 2007 6:03 pm
by Digix
I think D-T fusion have no big energy advantage in the fusor design. all you need to get same result with D-D is to increase voltage.

D-T fusion produces 2x more neutrons but somewhere about 50% less available energy also in D-T fusion its rate will decrease 2 times because only 50% of collisions are D-T

Re: found this interesting info in the P.T Farnsworth patent section

Posted: Mon Oct 15, 2007 4:13 pm
by Richard Hull
What! the only reason D-T is even dreamt of is that it produces nearly 3X more energy than D-D!!!!

D-T is cooking way before D-D even starts So it is less energy input and more energy output!!

Thus, D-T beats D-D both coming and going and stays on top at all levels. There is no voltage to which you could subject either reaction to under 1 million volts where D-D would better D-T.

D-D is just the only reaction we can use. Believe me, most of us would go to D-T if we could.

Richard Hull

Re: found this interesting info in the P.T Farnsworth patent section

Posted: Mon Oct 15, 2007 5:43 pm
by MarkS
Speaking of tritium, fusors are a source of fast neutrons (2.45MeV). Could one produce small amounts of tritium by irradiating Lithium 6 or 7?

Re: found this interesting info in the P.T Farnsworth patent section

Posted: Mon Oct 15, 2007 7:29 pm
by Carl Willis
Mark,

Irradiation of Li-6 with slow neutrons produces tritium: Li-6(n,a)T. With 100% conversion of neutrons (impossible due to the need to moderate, among other practical considerations), the hottest amateur fusors could only manage a few dozen microcuries at saturation (the assumption there is that you have operated the fusor continuously for your entire life and are now an old geezer).

Compare this number with the quantity of tritium in Trasers, gunsights, and watches (a few millicuries) or the amount found in exit signs (up to 20 curies).

So the operative word is "small."

-Carl

Re: found this interesting info in the P.T Farnsworth patent section

Posted: Mon Oct 15, 2007 7:34 pm
by MarkS
Rather smaller then I had in mind. How is Tritium produced commercially?

Re: found this interesting info in the P.T Farnsworth patent section

Posted: Tue Oct 16, 2007 10:47 am
by Richard Hull
You will make about 1000% more tritium in your fusor by doing nothing!! Tritium is produced every other fusion in a D-D fusor

One million fusions per second in a fusor produces 500,000 He3 atoms and 500,000 tritium atoms each second!

Trying to moderate the neutrons and lithium blanket a fusor could never under any circumstances more than double the tritium production already available for free without the complex moderator and blanket. As this is only theoretical, it would never double anyway.

As Carl notes, regardless of the fact that tritium is made without the lithium or with it in a complex combination, you could never operate a fusor so long as to collect any tritium of usable significance.

We have run all these numbers in many former postings on this very issue.

Tritium can be made readily with Li6-neutron reaction in a modern fission reactor where fluxes exist to produce in an hour, the amount of tritium a fusor would make in 10,000 years!

FORGET, FOREVER, TRITIUM MANUFACTURE WITH A FUSOR!

India and, formerly, Canada were the largest tritium producers in the world.

The US folded much of its tritium manufacturing following the end of the cold war. We bought what we needed until our H stockpile started to go sour. We decided it was not wise to rely on other nations for its maintanence. We now make just enough for defense needs. Commerce still imports.

Richard Hull