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Plasma focus fusion

  1. Dec 19, 2004 #1
  2. jcsd
  3. Dec 19, 2004 #2


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    Staff: Mentor

    Well it appears that there has been some legitimate interest:
    but then the statement in article at Progressive Engineer is worrisome:
    I suppose one can review the technical journal articles and draw one's own conclusion.

    The quality of the paper, Towards Advanced-fuel Fusion: Electron, Ion Energy >100 keV in a Dense Plasma by Eric J. Lerner, cited on ArXiv is somewhat disappointing.

    I suppose it is worthwhile to contact Freeman to get his perspective.
    Last edited: Dec 19, 2004
  4. Dec 19, 2004 #3
  5. Dec 20, 2004 #4


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    Staff: Mentor

    Follow up with Freeman

    I contacted Bruce Freeman regarding Lerner's claims.

    I was informed that -

    1. Freeman and Dr. Oona were not forced to withdraw support for the paper, they had disagreements with Lerner.

    2. Freeman indicated that Lerner was confusing ion energy and temperature, therefore the details in the paper are incorrect.

    3. The particle densities were high, but the average energies were very low.

    4. The Lerner claim for having achieved fusion conditions
    exceeding those of the tokamaks is false!

    I need to review the plasma focus concept, which seems to be similar to that of neutral beam injection. In either case, ions can be injected with high energies and fusion may occur without the injected ions being in equilibrium with the plasma.

    Warning: Just because an article is published in ArXiv, do not assume that it is necessarily accurate. Investigate through other independent channels.
  6. Dec 27, 2004 #5


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    Staff: Mentor

    The views that I have expressed in my previous post are my own and do not reflect those of my employer or Physics Forums.

    In support of the statement in the previous post:
    Using some numbers from the DIII-D Tokamak, the neutral beam injects D neutrals with an energy of 80 keV. The line averaged plasma density, is on the order of 1.7E14 cm-3, so with a beam energy of 80 keV, this would yield, 1.36E16 keV-cm-3. However the energy confinement time was given as 0.5 sec, so the [itex]n \tau E[/itex] would be 6.8E15 keV-sec-cm-3, which still exceeds the number quoted by Lerner in the ArXiv paper.

    But to use the neutral beam energy would be misleading, because the average ion plasma energy in DIII-D is only 27 keV.

    Data are taken from:


    Last edited: Dec 27, 2004
  7. Dec 28, 2004 #6
    Eric Lerner's Rebuttal

    Dear Folks,

    I sent this thread to Eric, here's his complete responce to me :

    "Erich, Thanks for informing of this. My reply is below. Please post it to the list in my name and feel free to post it elsewhere. The work was supported by Jet Propulsion Laboratory via contracts with Lawrenceville Plasma Physics and Texas A & M and by Texas Experimental Enginerring Station, part of Texas A&M. happy New Year! Eric

    My reply:

    In reply to Astronuc, I would be the first to agree that fusion is not easy with any device, including the DPF. If he is disappointed by my paper in specific ways, I’d be glad to discuss the physics in it.

    Bruce Freeman “contradicted” conclusions that he previously approved in detail, purely because his job was threatened. He continues to do so for the same reason. This is a matter of documented chronology. It’s an important matter because science should not be conducted on the basis of threats to people’s livelihoods, but on the basis of experiment and experimentally confirmed, valid theory.

    Here is the chronology in brief:

    Nov.15, 2001 : I sent to Bruce Freeman and Hank Oona of LANL a draft Letter for Nature, with all of us as co-authors. In the abstract, which is the first paragraph, it contained the following conclusion: “We have achieved this in plasma ‘hot spots’ or plasmoids that, in our best results, had a density-confinement-time-energy product of 5.5 x1014 keVsec/cm3, a record for any fusion experiment and a factor of ten above the best achieved in the much larger tokamak experiments.”

    Nov.29, 2001: Freeman sent a detailed word-by-word revision, with the following note. The tokamak sentence was still in. Freeman wrote:

    “Eric, I have gone through the article. The revised version is attached. Word was in a strike and add mode for editing. Mostly, it needed word smithing, but I did change emphasis in a few places.
    Later, Bruce”

    Dec. 4, 2001 Hank Oona sends his comments, also leaving the sentence unchanged:

    “Hi Eric and Bruce, I finally read the paper and made some minor suggestions. …In the mean time, I think it looks fine but I will go through it once more.Have a good day, Hank“

    Feb.11, 2002 After the paper was rejected by Nature, I sent Bruce and Hank a revised version for Science, still with the same sentence in the lead paragraph. Again, I received careful revisions from both, and again neither asked for changes in the sentence, or with the same claim made in the concluding paragraph. Again the paper was submitted in all our names.

    May 1, 2002: After submitting the paper, with Freeman’s and Oona’s consent, to Physica Scripta, I sent Freeman and Oona a draft press release, prior to presenting some of the results at an ICOPS conference, which contained the following: “The temperatures reached, up to two billion degrees in some shots of the device, well surpass previous records of 520 million degrees achieved by the tokamak device. The much larger and more expensive tokamak has been cornerstone of the US fusion program for 25 years. In addition, the product of the plasma density and the time the plasma lasts, (called the "density-confinement time product") was eight times more in the new plasma focus results than in the tokamak.” Again, I received no comments from Freeman or Oona that objected to this conclusion.

    May 9, 2002: Freeman posted the paper, still in all our names, and still with the same sentence in the abstract, to arXiv, thus making it public.

    But things changed after the press release was actually sent out May 21, 2002. On May 23, I received a call from Hank Oona, in which he reported that his job was threatened by Richard Siemon, a Los Alamos manager, if he did not withdraw his name from our paper. Siemon was informed of it by a reporter who had received the press release. Hank said he had no choice but to accede unless I could convince Siemon otherwise. The same day Bruce Freeman told me that Siemon had contacted the head of Freeman’s department, who had also insisted that he disassociate himself from the paper.

    These were phone calls, so people can chose not to believe me about them. But it was only AFTER being contacted by Siemon that Freeman and Oona changed their public stands on the conclusion drawn from our experiments. That same day I received from Freeman a note, demanding changes in the paper, which was cc’d to Siemon, others and Los Alamos and Alan Waltar, the head of Freeman’s department. In it Freeman said: “I must admit that I did see the abstract and ending comments in the paper and did not realize that you intended to claim nt records. I guess the press release that you propose should have shaken me awake.” This was after he had approved FOUR times the statement in the abstract that a record had been achieved—with the Nature paper, the Science paper, the press release and his own posting of the article to ArXiv!

    In saying that he wanted his name removed from the paper in this same note, Freeman explicitly said: ”Negative references to Tokamak research are inflammatory and do not serve a productive, scientific purpose. Therefore, these issues must be edited out of the document, along with all negative references to Tokamak work.” The ONLY references to the Tokamak in the paper were the comparisons, without other comment, of our best results with the best Tokamak results. It was abundantly clear that what was motivating the action was Siemon’s insistence that nothing imply that another device had achieved results better in any way than the Tokamak.

    Later the same day, Freeman emailed me that he too felt his job in danger. He wrote: “By the way, the reason that I copied the LANL folks is that you may have cost Hank his job. It was a feeble attempt on my part for damage control to his career. For that matter, mine may be in danger now as well.” Clearly, there would have been no reason for these cc’s if the job threats coming form Siemon had not existed. Without further discussion, or even notifying me, Freeman withdrew the arXiv paper, which I later re-instated in my name alone. Both Freeman and Oona removed their names, and the names of our other collaborators (grad students and technicians) from the paper. Oona’s email request explicitly cited his discussions with Siemon and was also cc’d to Siemon. In addition, I had extensive communication with Siemon both by phone and email, and Siemon himself made clear that it was his decision, not Oona’s, by referring in an email to “my refusal to allow this paper to be published with Oona's name on it”.

    Both Freeman and Oona remain at their same jobs today. I think this documented sequence of events makes clear that they were coerced into withdrawing from the paper and still are not at liberty to express their real scientific views on our experiments. There is absolutely no excuse for Siemon’s attempt to suppress scientific discussion by threats to scientist’s livelihoods. People who feel that their careers are on the line are hardly in a position to give forthright expressions of their views. I think it is obvious that those real views were adequately expressed in their careful reviews of articles submitted in all our names to three publications, in a press release that they reviewed and in an arXiv posting. Repression, like that employed by Siemon, poisons scientific discourse and makes it impossible for frank discussions to occur.

    The paper, in greatly modified form, and in my name alone, but still containing the same comparisons with Tokamak results, will be published as part of the Proceedings of the 5th Symposium on Current Trends in International Fusion Research, where it was given as an invited paper. It is also available on arXiv and at http://www.focusfusion.org/.

    I am more than happy to discuss the scientific issues involved in this paper. But it must be a free discussion, uninhibited by threats and administrative repression that have no place in the scientific community.

    Eric J. Lerner

    Lawrenceville Plasma Physics "
  8. Nov 14, 2009 #7
    Last edited: Nov 14, 2009
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