Neutron measurement during crushing of LiNbO3 crystals in D2 and H2 atmospheres​

  • Neutron measurement during crushing of LiNbO3 crystals in D2 and H2 atmospheres

    Masatoshi Fujii1, Kazumasa Kobayashi2, Yasuyuki Taniuchi3, Kenta Takeuchi4, Michiaki Utsumi4, Masami Chiba5, Toshiaki Shirakawa6, Tomoko Hashimoto7 and Fumio Shiraishi7

    Published 23 October 2017 • © 2017 The Japan Society of Applied Physics


    Japanese Journal of Applied Physics, Volume 56, Number 11


    A study of mechano-nuclear fusion during the crushing of dielectric crystals of LiNbO3 was carried out in three different atmospheres, D2 (101 kPa), H2 (101 kPa), and vacuum (1 Pa). The number of neutrons emitted during the nuclear fusion reaction was counted in a low background-neutron environment, 6.49 ± 0.02 counts/h, using 16 3He neutron counters with a detection efficiency of 8.6%. The observed neutron counts (±σ) during crushing in D2, H2, and vacuum were 6.39 ± 0.24 counts/h (111 h), 6.87 ± 0.20 counts/h (169 h), 5.92 ± 0.26 counts/h (89 h), respectively. The excess counts of neutrons were 0.47 ± 0.35 counts/h (significance: 1.3σ) (D2) and 0.96 ± 0.33 counts/h (significance: 2.9σ) (H2), assuming that the count in vacuum was zero. From these results, the upper limits of neutron generation in D2 and H2 were 12.2 and 17.4 neutrons/h with a confidence level of 95% (1.65σ).

  • background: 6.49 ± 0.02 counts/h

    crushing in D2: 6.39 ± 0.24 counts/h excess 0.47 ± 0.35 counts/h (significance: 1.3σ) (D2)

    crushing in H2: 6.87 ± 0.20 counts/h excess 0.96 ± 0.33 counts/h (significance: 2.9σ) (H2

    crushing in vac: 5.92 ± 0.26 counts/h assumed excess zero? what??


    Could someone familiar with the relevant technique please explain this? It just seems weird. I rewrote it to see it better. How is 6.39 ± 0.24 counts/h for D2, for example, higher than background of 6.49 ± 0.02 counts/h? Isn't it just noisier? Obviously, I am not familiar with this type of measurement or notation so of course, I could be missing something obvious... or not.

  • I know nothing about it but I thought muon-catalyzed fusion was also accepted... in fact, I know it is.


    https://en.wikipedia.org/wiki/Muon-catalyzed_fusion


    Quote

    If a muon replaces one of the electrons in a hydrogen molecule, the nuclei are consequently drawn 196[1][2] times closer than in a normal molecule, due to the reduced mass being 196 times the mass of an electron. When the nuclei are this close together, the probability of nuclear fusion is greatly increased, to the point where a significant number of fusion events can happen at room temperature.

    Current techniques for creating large numbers of muons require large amounts of energy, larger than the amounts produced by the catalyzed nuclear fusion reactions. This prevents it from becoming a practical power source. Moreover, each muon has about a 1% chance of "sticking" to the alpha particle produced by the nuclear fusion of a deuteron with a triton, removing the "stuck" muon from the catalytic cycle, meaning that each muon can only catalyze at most a few hundred deuterium tritium nuclear fusion reactions. So, these two factors, of muons being too expensive to make and then sticking too easily to alpha particles, limit muon-catalyzed fusion to a laboratory curiosity. To create useful room-temperature muon-catalyzed fusion, reactors would need a cheaper, more efficient muon source and/or a way for each individual muon to catalyze many more fusion reactions.

  • A few comments from someone who also knows little about this subject. Lithium niobate is a famous "non-linear" optical material used in laser amplification and particularly in wavelength harmonic generation, if I recall it correctly. The neutron numbers are rightly viewed with a bit of a yawn, from a magnitude standpoint. But it is apparently of interest because of the robust and reproducible nature of the rather puny but nevertheless "cold" generated signal.


    The muonic mass is 207 times that of an electron, (see Codata value at https://physics.nist.gov/cgi-bin/cuu/Value?mmusme), while having its identical unitary charge, if I recall correctly. And the same orbital ratio holds, that is the muonic unitary charge "orbits" at 1/207th the "radius" of an electron. I have mentioned here before the idea that a protonic orbital would be expected to be even closer to say an "anti-nucleus" consisting of say an aggregation of one or more electrons, muons or anti-protons and a stabiliizing number of anti- (or ordinary ?) neutrons. Nothing prevents a proton from briefly orbiting a negatively charged molecular entity, and acid catalyzed chemistry is filled with intriguing examples that might provide a far more accessible decay route to fusion without invoking difficult to synthesize muons. Naked protons are available from the action of quite conventional microwave ovens on hydrogen. They are also available (or nearly available) as "nearly naked" protons in superacids, such as SbF5/HF . Stable aromatic rings have inherently electron rich structural features and are quite chemically stable in many cases. But I digress.


    Codata value for proton mass is about 1836 times that of an electron. Hence that much closer "orbital" to an appropriate durable negatively charged "nucleus" of whatever sort.

  • And by the way, SbF5/HF is stably contained in PTFE (Teflontm) containers. Providing a hint at how one might make use of "naked protons" without rapidly destroying one's experimental apparatus. The only limit there may be the 400 to 500 C maximum temperature of PTFE, which decomposes rather than melts.

  • I recall from the 1950s, that 'columbium' was used as a moderator in early fission reactors (Hanford on the Columbia river). Of course that element is now officially named Niobium, and hence its particular neutron accessibility may also be of significance in the reported lithium niobate efforts reported.

  • The muonic mass is 207 times that of an electron, (see Codata value at https://physics.nist.gov/cgi-bin/cuu/Value?mmusme), while having its identical unitary charge, if I recall correctly. And the same orbital ratio holds, that is the muonic unitary charge "orbits" at 1/207th the "radius" of an electron. I have mentioned here before the idea that a protonic orbital would be expected to be even closer to say an "anti-nucleus" consisting of say an aggregation of one or more electrons, muons or anti-protons and a stabiliizing number of anti- (or ordinary ?) neutrons. Nothing prevents a proton from briefly orbiting a negatively charged molecular entity, and acid catalyzed chemistry is filled with intriguing examples that might provide a far more accessible decay route to fusion without invoking difficult to synthesize muons. Naked protons are available from the action of quite conventional microwave ovens on hydrogen. They are also available (or nearly available) as "nearly naked" protons in superacids, such as SbF5/HF . Stable aromatic rings have inherently electron rich structural features and are quite chemically stable in many cases. But I digress.


    Codata value for proton mass is about 1836 times that of an electron. Hence that much closer "orbital" to an appropriate

    Picking up and critiquing my own notion here: One difficulty with such a protonic/deuteronic analogy to muonic orbitals and their known fusion cross section, is that any molecular electronic bond as a negatively charged image- or pseudo-nucleus, no matter its interatomic bond strength, may not survive long enough for this sort of inverse atom analogy (cf. Holmlid's inverted atoms, BTW). The "tidal force" of an 1836 X electron mass would likely be overwhelmingly destructive to such bonds or such charge-carrying molecules.


    But what of single atoms with known ability to bear a naked negative charge as a long-lived radical? Photolysis of halogens (Cl2, Br2, I2) in gas or plasma phase interactions can provide relatively stable radicals, with iodine being most stable but also least likely undergo an internal transition (radio-iodine is famous for producing internal transitions, but in the wrong direction, IIRC). So in my novice understanding, iodide radical may not be a likely nucleus for in situ radical induced transmutation. Fluoride radical, however should be easily produced since the bond dissociation energy is 2.7 eV (P.W. Atkins, Physical Chemistry, 1978, p. 469). Thus, F radicals produced homolytically by blue light at 459 nm or shorter. With the caveat that homolytic cleavage chemistry of fluorine F2 is not as familiar as the higher weight halogens-- and toxicity / corrosivity are an ever present issue. If not fluorine, then at least chlorine is also readily accessible to homolytic cleavage by photons. Both fluorine and chlorine naturally abundant isotopes have quite high thermal neutron cross sections, BTW as near as I can tell, higher with the exceptions of 6Li and 7Li at 39 and 45 barns respectively, to wit: 19F =9.5 barns, and 35Cl =43.7 barns, far higher than virtually any other naturally abundant isotopes below titanium, which is 48Ti itself at 7.9 barns.

  • Continuing: So perhaps a gas phase, low pressure system in which a specifically tuned photonic dissociation by homolytic cleavage of a suitable diatomic element (many available, but halogens are easiest or at least most well understood in this regard). Likewise, perhaps a source of protons or deuterons, also dissociated to supply at least P+ if not P-, where P represents H or D or even T. Since there are known microwave dissociations producing protons and / or hydride ions, there should be no reason why such species cannot be co-produced in the gas phase.


    To lower the kinetic order of such reactions from two party fluid collisions, consider the following: A condensed or solid phase for one or the other of the interacting components. For example a metal hydride, as we continue to see discussed here.


    But, the final caveat here is that many of the above ideas could, if successful, result in often short-lived radioisotopes, especially if it is by neutron addition. Most candidates seem to have quite energetic (MeV) beta decays as at least the first step. But, at least such results should be readily measured and quantified by GM or scintillation counting.

  • Nanotools are not cheap

    Agreed, although GM (Geiger-Mueller) and scintillation counters can be had quite reasonably, used ones for the latter, lots around since scintillation counting in research in biochem and molecular biology is becoming rarer. In any case thanks for your interest bocjin.

    Nanotools are not cheap

    An afterthought: Chemistry, photochemistry, catalysis, etc. are relatively inexpensive "nanotools" known by more conventional names.

  • But, the final caveat here is that many of the above ideas could, if successful, result in often short-lived radioisotopes, especially if it is by neutron addition.


    Neutron capture as it is known experimentally and in neutron activation analysis results in radionuclides with a broad range of activity. The activity of some daughter nuclides is short-lived and that of other nuclides is long-lived. Unless the proposed process somehow goes beyond the usual neutron capture, the long-lived radionuclides that would be produced would rule out the scenario as an explanation for LENR. for which long-lived radionuclide daughters are unknown. (Generally speaking.)

  • Surely, so the focus is clearly on short-lived daughter nuclides. ULM (<7 m/sec) neutrons are supposed to be a source for such nuclides. Those decay energetically, or not? And have they been studied much? Is the energy yield from the short term decays inherently too weak to do work?


    There must be simple means to classify and study such neutrons and especially their very short lived products.

  • If ULM neutrons also activate a nontrivial number of long-lived radioisotopes, then presumably we can set them aside as a viable explanation for LENR. Do you recall your source for the suggestion that ULM neutrons produce short-lived radionuclides?


    Another big challenge with neutron capture is that when a neutron is captured by a nucleus, the daughter nucleus may be several MeV above the (often radioactive) ground state. The excited state is generally relaxed by way of emission of a gamma photon shortly after the capture. This would be true even if the incident neutron had very little momentum, and the ground state of the daughter was not radioactive, because there will be a significant difference in the mass of the parent and the mass of the daughter in the ground state after the capture. (This is the problem that led Widom and Larsen to propose that the gammas were thermalized by heavy electrons.)

  • The problem of the MeV outcome of daughter state is key to LENR.

    Trying to stay in mainstream physics, Storms concluded the quanta are split because of multiple intermediate states, requiring collective phenomenon. No idea how, but I think it is unavoidable.


    LENR is collective or there is new physics.

  • I'm skeptical that new physics as drastic as that is needed (splitting up an MeV quantum into small pieces). My tentative conclusion is that Storms and others are drawing too strong of theoretical conclusions from the patchy experimental evidence available. I think accelerated decay and fission of otherwise stable elements will fit the data pretty well. This is new physics, but also physics that undergraduate physics students might anticipate (and probably do). In that sense it is only slightly new physics. I am quite sympathetic to the complaints from people knowledgeable in physics about the difficulties of surmounting the Coulomb barrier to obtain fusion at low energies.