In this space, visitors are invited to post any comments, questions, or skeptical observations about Philo T. Farnsworth's contributions to the field of Nuclear Fusion research.
Subject: Re: D+D Cross section
Date: Oct 29, 9:02 pm
Poster: Richard Hull
On Oct 29, 9:02 pm, Richard Hull wrote:
>Whoa....Richard. This appears to be nothing more than a hypothesis that has been concocted by Tom
>Lignon and others to justify the observed neutron production of the fusor, but where is its basis in fact?
This question was asked and answered by a Physicist on the Ask a Scientist section of the Princeton Plasma physics network about 2 years ago when this question was fresh. He stated that when using tables for D-D fusion computed for a deuteron in motion hitting a stationary deuteron one would have to use the 4 times energy level to determine head on collisions involving deuterons of similar energies. This is in an effort to reflect a change in regime for the process. He is the physicist and not me. (most D-D fusion cross section charts are moving and stationary target deuterons.)
Of course in a simple fusor, the exact number of 100% head-ons is about .000000006% of the total population entering the inner grid or even less in some cases. It ain't efficient, but I have no doubt that it is fusion. For the temperature is right for those lucky deuterons.
Head-ons are 100% by statement, the number of head ons is a function of the current, gas pressure and the percentage of ions falling through the full potential that arrive aligned and un-molested. (tiny fraction) This factor is due to construction and engineering of the ion producing system. Ion guns do better, but are very expensive.
There are no tables offered up on stripping, Low Z fission or accelerated deutron decay or any other imagined processes for neutron production in lamps, fusors or tokomaks. Only D-D cross section graphs which are well defined, well known and readily available. I'll use the extant data, accepted charts, to back up my findings. RH
>Bottom line is that by sticking with the thermonuclear explanation, you will assume an effective temperature of 880 million degrees in a fusor
In a tiny zone of the fusor, YES, and only for the lucky few deuterons. I am not heating bulk gas in a plasma ala thermal machines or lamps!!! RH
and reject out of hand the possibility that some other reaction is responsible or contributive.
Not reject out of hand. I just must be shown physical data culled from a fusor, run similarly, that refutes accepted physical fusion cross sections, and absolutely proves a totally different mechanism to be operable. I have no problem with mother goose dispensing the neuts as long as some one shows me her doing so. RH
>RH> As not one human being has posted on the energy required to strip neutrons from deuterons I hold it out as a maybe as no data has been forth coming. I have written and contacted many labs and
>physicists on this and consulted a number of books.
>This is true of course, but we are dealing with a new hypothesis and no one has yet obtained funding to flesh out the details. It might even be found at some future date that many of the old cross sectional tables are flawed because they failed to remove the effects of stripping from their data.
Possible, but not in evidence. RH
>I cannot say with certainty that stripping is a hypothesis that should be given equal weight with Lignon's but I can say that when his is presented, it should be clarified that it is ONLY a hypothesis - and a big stretch at best.
>RH> Not one scientist had a clue as to what energy would be required. The binding energy of the
>deuteron is such that a successful striping operation would be a net....
>Yes, of course. There is the question of what happened to the missing ~Mev. But if neutrons are stripped by charge clusters, for instance, and the cc is as large as Shoulder's now believes (Avogodro's #) then the average excess energy that would be imparted to each electron, if shared equally, is far less than an ev - and the cc will deposit that as heat only on the anode.
I have seen the ev and related charge cluster stuff offered up for more cause and effects ranging from cold sores to nuclear waste remediation. It is unfortunately just the latest catch all for unknown processes to hang their hats on. As with all this stuff I will wait and see where it goes. Most of this stuff's forerunners are now just GONE!
New energy, bizarre processes, and fusion power are of course where they always have been.........just around the corner. The results and proof are coming ......real soon now.
I have been part of the new energy community for years, Mostly as an observer/researcher, but remain undeceived by its promises, and un-impressed by its deliveries. The corpses in the wake are many. (MRA, Floyd Sweets magic box, Hendershots device, and others no longer talked about). Scott Little and I love to look at the failures and are disheartened by the bad science done by the bulk of the community. Most of it involving idiot measurment techniques coupled with lots of self-deception where a lone wolf researcher discovers the "key to everything"!
I'll stick with mainline explainations for the neutrons I am getting for the moment and revel in the inefficiency.
>RH> There is zero evidence regarding accelerated decay and zero data on low z fission which is just
>striping times two.
>How much "real" evidence is there for thermonuclear fusion? I proposed what is the obvious experiment to clear this up back in August. It seems so easy that it should have been done long ago, but I can find no evidence that it has. The only real test to find the extent of stripping vis-a-vis real D-D fusion in a Fusor
>or any plasma device would be careful analysis with a mass spectrograph of the ash.
>RH>When one does the math and allows for the collisional focused nature of this device and the reduced volume of the reaction zone, using the D-D cross section curves, the amount of neutrons seen is not far from the predicted amount due to FUSION.
>Only if you blindly take that GIANT stretch and look "way up the D-D curve." You are far removed at 60 kev and even that is assuming 100% head-on collisions in the convergence zone.
>RH>Folks can claim it is striping but give us a number! A striping cross sectional curve with input energy graph, and we can compute form there to see what gives...
>That number may already be part (the tail) of the so-called D-D fusion cross sectional curve, but it would take some big bucks to prove it.
>I am not trying to be argumentative here, but I have seen no convincing proof that these issues have been resolved - or even adequately addressed. If you are serious about advancing the state of the art of the fusor, rather than just producing neutrons for the show of it, it would seem unwise to discard any hypothesis only because the "fusion establishment" doesn't yet give it much merit. After all, aren't they the ones that have blown $billion in recent years with precious little to show for it? I doubt there is a greater failure in modern science then the fusion establishment.