Return to the clickable list of items
140) Seven papers from Kasagi
Ludwik Kowalski (5/1/04)
Department of Mathematical Sciences
Montclair State University, Upper Montclair, NJ, 07043
This morning I received an e-mail message from Kasagi in Japan. He wrote: “Recently, I have found your www site on cold fusion by chance. And I knew, in the essay, that our works on low energy nuclear reaction have been cited several times. I appreciate it very much. I noticed that some of our papers are not in your hands; for example, that gives a detailed description of the experiment, spectra of observed particles, and so on. Thus, I decided to send them. Please find attached files (pdf files), which are our published papers on LENR in refereed journals.” I am pleased that a scientist like Kasagi read my entries on this site. What follows are my short summaries based on fast reading of these seven paper. Dr. Kasagi saw the draft of this unit and made several small corrections.
At the same time (5/4/04) he wrote: “I started this kind of research in 1989, of course, after the big announcement [of the discovery of cold fusion]. Since I thought that low-energy nuclear reactions in materials were not investigated, I decided to measure DD reaction rates in metals by lowering incident energies as low as possible. The paper #2 is based on the work in 1989-1990 by using an ion source at Tokyo Institute of Technology where I was working at that time. I also started to observe reaction products during and after deuteron bombarding on metals. The paper #1 is based on the work in 1990-1994 by using a small Cockcroft-Walton machine in Tohoku University, where my friend was working for the Cyclotron laboratory, and, later on, I moved to the Laboratory of Nuclear Science (we have electron machines here). Thus, what led me to the cold fusion field was the original works of Fleishmann-Pons and Jones, although the first publicatio on this subject in the refereed journal was delayed too much.”
Paper #1 (1995)
(1) J. Kasagi, T. Ohtsuki, K. Ishii and M. Hiraga, Energetic Protons and alpha-particles Emitted in 150-keV Deuteron Bombardment on Deuterated Ti, J. Phys. Soc. Jpn, 64, 777-783 (1995)
Deutrons of 150 keV were used to bombard a thick target of Ti loaded with D. In addition to expected 2.45 protons from the D(d,p)T reaction they discovered unexpected protons of 17 MeV and alpha particles of 6.5 MeV. The Ti, before loading it with D, was 99.5% pure and chemical composition of the remaining 0.5% (mostly O and Fe) was shown in the table. These people know that extraordinary claims call for extraordinary evidence and they investigated many kinds of scenarios, such as reactions in impurities, reactions due to neutrons, protons and 3He. Here is one example. The dominant D(d,3He)n reaction produces neutrons and 3He. Thus targets were exposed to deliberately stronger doses of 3He and n in order to show that not enough alpha particles were produced. Some protons could be explained as due to the D(3He,p)4He reactions (whose Q value is 18.35 MeV) but most high energy protons must be due to something else, claim the authors. Similar discussion was presented to rule out a possibility that most of the 6.5 MeV alpha particles are due to known reactions.
I was pleased to read this paper because I am familiar with instruments described by authors. They are similar to instruments I used in postdoctoral work at Columbia University about 35 years ago. It is interesting that the word “cold fusion” is not mentioned. Was it because the topic was considered pseudoscientific in Japan (as described in Mizuno’s book) or because this work led the authors to cold fusion? In order to interpret the results they speculate that (for unknown reason) deuterons in Ti are sometimes much closer to each other than distances between Ti atoms. That would allow the D+D+D --> p+n+ a reaction in which the available energy of 21.62 MeV is shared among three products. The authors conclude: “However, this possibility requires an anomalously large enhancement factor which is not understood at present.”
P.S.
The term LENR (low energy nuclear reactions) certainly appropriate for this study. But the term CF (cold fusion) is not appropriate because, by my definition in unit # 136, “Cold fusion is any process in which a nuclear reaction is produced without relying on traditional means, such as particle accelerators, neutron sources, stellar temperature temperatures, cosmic rays or alpha particles.” Yes, formation of compound nuclei can be called fusion (of two nuclear drops) but even 150 keV is not “cold.”
Paper #2 (1995)
J. Kasagi, T. Murakami, T. Yajima, S. Kobayashi and M. Ogawa, Measurements of the D+D Reaction in Ti Metal with Incident Energies between 4.7 and 18 keV, J. Phys. Soc. Jpn. 64, 3716-3722 (1995)
This paper is also devoted to D+D reactions in Ti but the energies of projectiles are lowered to 18 and 4.7 keV . Reaction cross sections, in that energy region, are very small, due to the Coulomb barrier. But they are known to be larger than expected. This effect has been attributed to screening (lowering of Coulomb barriers caused by orbital electrons. That is why the distance hydrogen nuclei in Ti and Pd are much shorter than H2 molecules. Studying of screening effects was the motivation behind this investigations. Is this a camouflage for the “forbidden word” - cold fusion? The lowering of the Coulomb barrier is expressed in terms of so-called astronomical factor, S, (obtained by dividing a measured reaction cross section by the Gamow factor and by the incident energy). The main conclusion of this work is that screening in Ti is not significantly different from screening in a gas target (reported by other researchers).
Paper #3 (1997)
H. Yuki, T. Sato, T. Ohtsuki, T. Yorita, Y. Aoki, H. Yamazaki, J. Kasagi and K. Ishii, Measurement of the D(d,p)T reaction in Ti for 2.5 < Ed < 6.5 keV and electron screening in metal, J. Phys. Soc. Jpn. 66, 73-78 (1997)
This paper is also devoted to the study of D(d,p)T reaction in Ti but beam energies were between 2.5 and 6.5 keV. This was possible because the new accelerator was able to produce beams up to several hundreds microapmers (instead of only 2 in the previously used machine). Slight enhancement of cross sections (over those in bare D+D reaction) was noted. It was interpreted as caused by the electron screening. The first reference is for the “effect of the electronic environment on nuclear phenomena.” It is G.T. Emery in Annu.Rev. Nucl. Sci. 22 (1972) 165.
The second reference is the 1989 CF paper of Fleischmann and Pons. The authors gave a very good description of controversies in that field; they wrote: “The so-called cold fusion has roused attention more generally on the influence of the environment where nuclear processes take place. Although most of the experiments reported at that time were known to have a difficulty in the reproducibility and, hence, to be under suspicion, the influence of the environment in various nuclear processes is one of the interesting subjects which need more study, because of its interdisciplinary nature involving nuclear physics, condensed matter physics, material science, and so on. In addition, one can develop its applications in various fields if the electron environment really affects the nuclear processes very strongly.”
The paper focusses on difficulties of obtaining reliable data on cross sections in the region of very low energies. Overcoming some of these difficulties the authors demonstrate the enhancements of cross sections below 4 keV. The value of the screening potential for the D+D in Ti is reported as 19 eV, plus or minus 12 eV.
Paper #4 (1997)
H. Yuki, T. Sato, T. Ohtsuki, T. Yorita, Y. Aoki, H. Yamazaki and J. Kasagi, The D+D reactions in metal at bombarding energies below 5 keV, J. Phys. G: Nucl. Part. Phys. 23, 1459-1464 (1997).
This paper, published in an journal is devoted to the same topic as the previous paper. It shows that enhancements of D+D reactions in Yb are stronger that in Ti. The screening potential in palladium is reported as 81 eV, plus or minus 10 eV.
Paper #5 (1998)
H. Yuki, J. Kasagi, A.G. Lipson, T. Ohtsuki, T. Baba, T. Noda, B.F. Lyakhov and N. Asami, Anomalous enhancement of DD reactions in Pd and Au/Pd/PdO heterostructure targets under a low energy deuteron bombardment, JETP Letters 68 (1998) 823-829.
This paper is devoted to the same topic as the previous two papers but the metal is Pd (palladium). The enhancements in Pd (250 eV, plus or minus 15 eV.) was found to be much stronger than in Ti and Yb. Even more pronounced enhancements (601 eV) is reported for Au/Pd/PdO heterostructure. The authors believe that conductive electrons (due to mobility of D ions in Pd) might contribute to very large enhancements in Pd and in Au/Pd/PdO sandwich.
Paper #6 (2002)
J. Kasagi, H. Yuki, T. Baba, T. Noda, T. Ohtsuki and A.G. Lipson, Strongly enhanced DD fusion reaction in metals observed for keV D+ bombardment, J. Phys. Soc. Jpn, 71 (2002) 2881-2885.
This paper elaborates on results obtained in the previous one and provides additional data on enhancements in PdO. The authors begin by showing how the maximum possible deuterium density depends on temperature in several metals. In Ti, for example, the density is about 4*1022 atoms per cubic centimeter while in Au it is about two times less. In Pd, on the other hand, the density is about ten times smaller that in gold. In all cases the saturation density decreases with the temperature, as illustrated in Figure 1. Great effort was made to keep the deuteron densities stable during bombardments with highly intensive deuterium beams. The discussion focusses on the observed correlation between the deuterium densities (smaller in Pd) and screening potentials (largeer in Pd). The authors speculate that low density may indicate increased “fluidity” which in turn leads to a screening caused “not only by electrons but also by positive ions.”
Paper #7(2004)
J. Kasagi, Y. Yuki, T. Baba, A. Taguchi, M. Shimokawa and W. Galster, Strongly enhanced Li + D reaction in Pd observed for deuteron bombardment on PdLix with energies between 30 and 75 keV, J. Phys. Soc. Jpn. 73 (2004) 608-612.
This very recent paper paper also indictaes that “the enhancement in the Pd case cannot be explained by electron screening alone.” The conclusion is reached by analyzing the energy dependence of cross sections for Li(d, a) reactions occurring in host metals (Pd and Au). Beam energies were between 30 and 75 keV. Screening in PdLi (~1500 eV) was found to be much stronger than in AuLi (~60 eV). As in the previous paper, the authors speculate that high fluidity of Li ions in the Pd host might be responsible for the strong enhancement.