CFRL English News No. 32 (2002. 2. 10)

Cold Fusion Research Laboratory (Japan) Dr. Hideo Kozima, Director

                            E-mail address; cf-lab.kozima@pdx.edu

                            Websites; http://web.pdx.edu/~pdx00210/

 

   This is CFRL News (in English) No. 32 translated from Japanese version published for Cold Fusion researchers by Dr. H. Kozima, now in Physics Department and Low Energy Nuclear Laboratory (J. Dash, Director), Portland State University.

In this issue, there is a following item.

1) On the Q, 4He, 3He and 3H measurements in Experiments with “Arata Cell”.

 

1. On the Q, 4He, 3He and 3H measurements in Experiments with “Arata Cell”

 

Helium-4 (4He) has a special meaning in the cold fusion (CF) research done in these more than 12 years. In free space, d-d fusion reaction has three branches to produce (1) 3H and neutron, (2) tritium and proton and (3) 4He and gamma with branching ratios 1, 1 and 10– 7, respectively.

In CF experiments, however, 4He has been measured fairly often with amount corresponding to the excess heat Q (by possible nuclear reactions). Claim of d-d fusion occurrence in solids, raised by some CF researchers based on this fact, has made many physicists stay outside of CF research who believe in applicability of quantum mechanics to solid state and low energy nuclear physics.

Recently, there have been several observations of 4He in experiments with using cathodes of the same type (Arata cell). Interesting experimental results [1 to 4] are investigated by the TNCF model giving a consistent and semi-quantitative explanation for (1) the excess heat Q and 4He generation outside the cathode and (2) tritium detection in the cathode containing Pd-black but not helium isotopes. Main characteristics of these data sets are summarized as follows*:

 

1. Y. Arata et al. have been measuring excess heat Q and nuclear products using Arata-style cathodes (Arata cells) [1]. Their claim is excess heat of the order of 100 MJ and accompanying production of 4He of the order of 1015 /cm3 or more in the hollow of the cathodes containing Pd-black in about 3 months.

 

2. McKubre et al. performed experiments with Arata cells and obtained similar results on the excess heat Q as those of Arata et al.; excess heat of about 64 MJ from a cathode in about 3 months.[2]

 

3. W.B. Clarke [3] investigated 3He and 4He concentrations in the hollow of Arata cells containing Pd-black supplied by Y. Arata through R. George, which produced excess heat, amount of which is in the order of 100 MJ. A negative result of 4He and 3He investigation was obtained which showed that 3He and 4He concentrations were factors of 109 and 106 times smaller respectively than the results of Arata and Zhang for similar samples.

 

4. W.B. Clarke and B.M. Oliver[4] investigated tritium, 3He and 4He concentrations in the hollow of Arata cell containing Pd-black supplied by Y. Arata and undergone prior electrolysis by M.C.H. McKubre et al. at SRI.[2] The results for 4He are similar to those of [3], i.e. very small amounts of 4He which are probably (by their opinion) due to trapped atmospheric helium in the samples. 3He is interpreted as a decay product of tritium, and tritium is 2 – 5×1015 atoms in the hollow cathode. Furthermore, Clarke et al. found an upper limit of 5.5×1010 atoms 4He in the outer 0.1 mm layer of the electrode. This means that less than 1 part in 300 million of the “expected” (from d-d fusion reaction compatible with the excess heat) amount of 4He was deposited (or recoiled) into the outer surface of the Pd electrode.

 

5. Comments on the experimental data sets.

The amount of tritium observed in the cathode [4] corresponds to the total released energy between 1.3 – 3.1 kJ (if reaction is d + d = t + p + 4.03 MeV) or 2.0 – 4.8 kJ (if reaction is n + d = t + gamma (6.25 MeV)) which are too small compared with values observed by Arata-Zhang of about 100 MJ [1] for similar and by McKubre et al. of 64 MJ [2] for the same cathodes and D2O electrolysis.

 

6. I have been doubtful about d–d fusion to occur in solids at near room temperature (cf. CFRL News No. 27, Comment to Item 2 by T. Chubb). So, I have made calculations using the TNCF model on the experimental data sets on the Arata cells obtained by McKubre et al. [2], Clarke [3] and Clarke et al. [4] to see if I can get any clue clarifying mechanisms behind CF data sets.　(Details of this calculation will be presented elsewhere.)

Data sets used in the calculation are: Excess heat generation of Q = 64 MJ in three months [2], absence of 4He in the cathode [3,4], tritium generation of Nt = 2.0 – 4.8×1015 atoms in the cathode, and an upper limit of 5.5×1010 atoms 4He in the outer 0.1 mm layer of the electrode as a whole in three months [4].

 

(a) We can determine the parameter nn of the TNCF model from the excess heat Q assuming PdLi surface layer of 1 micron thick on the cathode surface and a reaction n + 6Li = 4He + 3H + 4.8 MeV.

Then, the heat of 64 MJ in three months gives nn = 9.0×109 /cm3 at the surface of Pd cylinder of Arata cell according to the recipe of the model. The expected number of 4He from this reaction in this model is 8.3×1019  as a whole if all the heat generating reactions are the same n-6Li reaction (one 4He atom per 4.8 MeV). It should be remembered that this mechanism had shown its consistency with experimental data sets obtained by Morrey et al. and Miles et al. [5,6,7]

(b) We can calculate the expected amount of tritium Nt by a reaction n + d = t + gamma (6.25 MeV) in the cell assuming that nn in Pd-black is the same to that in Pd cylinder. Nt value obtained using this assumption on nn will give ambiguity in final result of one or two orders of magnitude. (The gamma in this reaction does not necessarily mean a real photon but phonons or other modes in solids participating in the reaction.) The expected amount of tritium produced in three months by this reaction is Nt = 8.1×1016 atoms (if 6Li is 7.4% as natural abundance). This figure is compared with the experimental value 2.0–4.8×1015 tritium atoms measured by Clarke et al.[4]. To meet this experimental value (we take here 2.0×1015), we have to take nn = 3.7×108 /cm3 (with natural abundance 6Li) showing two order of magnitude lower trapped neutron density in the Pd-black than in Pd wall of the cathode in our model. For a while, we do not know what this values of nn mean in reality.

(c) To consider the amount of helium 5.5×1010 atoms 4He in the outer 0.1 mm layer of the electrode[4] compared with expected value of about 1020 atoms as a whole (cf. (a)), it is necessary to check the treatment of the cathode before this measurement. It is said that the electrodes remained in open circuit until February 27, 1999 [after the end of electrolysis on Jan. 29, 1999], when the electrode polarity was reversed, and electrolysis continued until May 11, 1999. This process of electrolysis with reversed polarity results in taking off of PdLix layer of about a few microns on the cathode surface.** From our analysis of various data sets, nuclear reactions including 4He production occur in the surface layer of thickness about several microns. So, it is natural that they did not observe enough 4He in the cathode surface after taking off of the surface layer of PdLix . The amount 5.5×1010 atoms 4He corresponds to 6.6×10– 8 % of the expected 4He from the reaction n + 6Li = 4He + 3H + 4.8 MeV. In the analysis of the data by Morrey et al. [5], we concluded that 3% of generated 4He was remained in the surface layer of about 25 micrometer. The value 6.6×10– 8 % is very small compared with this value and shows that the surface layer active to the CF reaction was taken off completely by the electrolysis with reversed polarity.

(d) There remains a problem in this interpretation. Clarke et al.[4] measured distribution of 3He in the wall of the Pd electrode and found it’s density gradient directed outwards, i.e. density is higher inside and lower outside. If the n-6Li reaction producing tritium with the same number as 4He occurs on the outer surface and the 3He is the decay product of tritium, the gradient should be opposite. It is conceivable, however, that the PdLi layer on the surface prevents flow of tritium inward and only tritium in the wall is that generated in Pd-black in the inside hollow which flows out resulting in the observed profile of the decay product 3He.

(e) The reaction n + 6Li = 4He + 3H + 4.8 MeV assumed in (a) generates helium-4 and tritium with amounts 8.3×1019 as a whole corresponding to the excess energy Q = 64 MJ[2] in the outer surface of the electrode. Furthermore, it is capable to occur nuclear transmutations of elements in the surface layer of the cathode generating excess heat and heavy elements.[8]

Therefore, it is possible to make clear if the story composed of the experimental data sets by the TNCF model described above is true or not by measurements of 4He and 3H in the electrolyte and gas, and transmuted nuclei in the surface layer and electrolyte used in the experiment.[2] About these measurements, it is not written in the paper[2] and we cannot discuss this problem furthermore.

 

7. Thus, our model gives a consistent and semi-quantitative explanation of experimental data sets[2,3,4] obtained for Arata cells using quantum mechanics and knowledge of solid state and nuclear physics except the problem of 3He distribution in the cathode wall. The 4He data by Arata et al.[1] is not consistent with others from our point of view. About the reliability of experiments, I would like to trust rather the data by Clarke[3] and Clarke et al.[4] obtained by experts of 4He mass spectroscopy.

It should be noticed here that the value of the parameter nn = 9.0×109 /cm3 in the wall of the Arata cell determined above from experimental data sets [2,3,4] is in the range of the values (108 –1013 / cm3) [9] determined for about 60 data sets obtained in various conditions.

 

8. It has been shown theoretically that d-d fusion in solids is not possible to occur at a rate sufficient to explain observed data of CFP [10,11]. This theoretical fact made many physicists stay outside the CF research.

On the other hand, some researchers in CF seek a clue to explain the data of 4He by the d-d fusion realized in solids by assistance of phonons in the solids. The distance between atoms in relevant solids is, however, of the order of 10–8 cm and any phonon do not have a wavelength less than this order of magnitude. The range of nuclear force is 10–13 cm and it is necessary to make d-d distance close to this value to realize their mutual fusion reaction. Phonons with wavelength of 10–8 cm do not work in this job because they could not distinguish the distance less than their wavelengths.

These theoretical “facts” in addition to experimental facts described above in Section 6 show that we have to seek other mechanisms to explain experimental data of the excess heat, 4He and tritium and others in CFP.

 Furthermore, there occurs CFP not only in deuterium systems but also in protium systems. If we want to look for a common cause of CFP in both systems, the long-sought d-d fusion reaction in solids must not be considered as one of fundamental mechanisms.

 

9. There are some comments on the experimental data sets obtained by Clarke[3] and Clarke and Oliver and others [4]. They are going to be published in forthcoming FS&T. We hope a part of them will be introduced in this News before ICCF9 to serve your understanding of what are discussed in them.

 

(*) In CFRL News No. 31, Article 2, there are my comments on the papers referred as [6, 7, 8] in that article. There are inappropriate expressions in the comments. Correct introductions of these papers are given in this article (2. to 4.). The author would like to beg readers’ and authors’ pardons for them.

 

(**) In the analysis of Arata’s data on 4He presented in “Discovery, Section 11.8d”[9], we assumed existence of PdLi alloy in the region where 4He was observed. This assumption is not applicable to inside of the Arata cell where Pd-black is shielded in. Therefore, the calculation in the “Section 11.8d” should be applied to 4He production outside the cathode and not to inside where Arata et al. claimed detection of large amounts of 4He up to 1020–1021 /cm3 in one of their former papers [1,9].

 

References

(1) Y. Arata and Y.-C. Zhang, “Anomalous Production of Gaseous 4He at the inside of ‘DS-Cathode’ during D2O-Electrolysis,” Proc. Japan Acad., 75B, 281 (1999) and their papers cited therein.

(2) M.C.H. McKubre, F.L. Tanzella, P. Tripodi, and P. Hagelstein, “The Emergence of a Coherent Explanation for Anomalies Observed in D/Pd and H/Pd Systems; Evidence for 4He and 3H Production,” Proc. 8th Int. Conf. Cold Fusion (Lerici, Italy, may 21 – 26, 2000), p.3, F. Scaramuzzi, Ed., Italian Physical Society (2001).

(3) W.B. Clarke, “Search for 3He and 4He in Arata-Style Palladium Cathodes I: A Negative Result,” Fusion Science and Technology, 40, 147 (2001).

(4) W.B. Clarke, B.M. Oliver, M.C.H. McKubre, F.L. Tanzella, and P. Tripodi, “Search for 3He and 4He in Arata-Style Palladium Cathodes II: Evidence for Tritium Production,” Fusion Science and Technology, 40, 152 (2001).

(5) J.R. Morrey, M.W. Caffee, H. Farrar IV, N.J. Hoffman, G.B. Hudson, R.H. Jones, M.D. Kurz, J. Lupton, B.M. Oliver, B.W. Ruiz, J.F. Wacker and A. van Veen, "Measurements of Helium in Electrolyzed Palladium," Fusion Technol., 18, 659 (1990).

(6) M.H. Miles, B.F. Bush and J.L. Lagowski, “Anomalous Effects Involving Excess Power, Radiation, and Helium Production During D2O Electrolysis Using Palladium Cathodes,” Fusion Technology, 25, 478 (1994).

(7) H. Kozima, S. Watanabe, K. Hiroe, M. Nomura, M. Ohta and K. Kaki, "Analysis of Cold Fusion Experiments Generating Excess Heat, Tritium and Helium," J. Electroanal. Chem. 425, 173 (1997) and 445, 223 (1998).

(8) H. Kozima, K. Arai, M. Fujii, H. Kudoh, K. Yoshimoto and K. Kaki, "Nuclear Reactions in Surface Layers of Deuterium-Loaded Solids," Fusion Technol. 36, 337 (1999).

(9) H. Kozima, Discovery of the Cold Fusion Phenomenon–Evolution of the Solid State - Nuclear Physics and the Energy Crisis in 21st Century, Ohtake Shuppan KK., Tokyo, Japan, 1998, (cf. Tables 11.2 and 11.3).

(10) A.J. Leggett and G. Baym, “Exact Upper Bound on Barrier Penetration Probabilities in Many-Body Systems: Application to “Cold Fusion”,” Phys. Rev. Lett., 63, 191 (1989).

(11) S. Ichimaru, “Nuclear Fusion in Dense Plasma,” Rev. Mod. Phys., 65, 255 (1993).