Fusion Message Board

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, 4:02 pm
Poster: John Franks

On Oct 29, 4:02 pm, John Franks wrote:

>In an earlier thread, Richard Hull stated:
>>A 30kv fusor works not at the 60kev deuteron part of the cross sectional fusion D-D curve but much
>higher up due to the focused collisional nature of the device...
>
>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?
>
>Can you show any independent reference that justifies a quadrupling of collisional energy and at the same time lets you maintain the assumption of 100% head-on collisions in the reaction zone? You can't have it both ways.
>
>I personally find it curious that you can propound what clearly is a violation of conservation of energy laws without considering the possibility of other explanations, however unsupported they may be by the "establishment" at the present time.
>
>Bottom line is that by sticking with the thermonuclear explanation, you will assume an effective temperature of 880 million degrees in a fusor and reject out of hand the possibility that some other reaction is responsible or contributive.
>
>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.
>
>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.
>
>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.
>
>Jones
In answer to your question on deuteirium stripping it takes a collision with a photon of energy 1.2 mev to split the neutron off. This can occur in gas on the higher energy side of the Maxwell boltzman distribution. By the way you guys, be carefull,start looking into shiielding if you want to investigate this stuff further.