ANOMALOUS NUCLEAR REACTIONS IN CONDENSED MATTER I. AHMAD, ARO-FE Abstract: This note summarizes the highlights of the Third International Introduction: In 1989 Fleishman and Pons of the University of Utah announced that electrolysis of a solution of L10D in heavy water, using palladium as a cathode generated heat which was much in excess of what could be predicted from the considerations of heat input (resistive) and electrochemical processes involved. They reported power densities in the range of a kilowatt per cubic centimeter of the electrode. They claimed that such excess energy could be generated only from some anomalous nuclear reactions occurring in the palladium cathode used. While the claim received immediate support from S.Jones of the Brigham Young Univrsity and ambiguous confirmation from some groups in US and abroad, a large number of research groups could not reproduce Dr. Fleishman and Pons' (F&P) results of excess heat. Also questions were raised that if the excess heat was due to a nuclear reactions there should be concomitant nuclear products which could be predicted from the established nuclear physics principles. Again there were conflicting reports of the detection of neutrons, tritium and helium, but in general not unambiguously accompanied by the generation of excess heat. This created in the scientific community considerable confusion, controversy and distrust, culminating into open doubts in the integrity of the researchers involved. So much so that the term "cold fusion" became a taboo, particularly in the United states. Most of the research funding particularly by the Government agencies was reduced or terminated. In spite of the above, many scientists agreed that observations of the neutrons, helium and excess heat, even if they were not reproducible, did indicate that some unexplained new phenomena were occurring under the condition of the electrolysis used by F&P and many others. In Japan, Italy, USSR, China and even in US low level studies continued. For example in USA, EPRI continued to support work at the SRI and Texas A&M University. Some workers such as Miles in Navy's China Lake laboratories and Storm at the Los Alamos National Labs continued their research, again at a low level. Some of this work was reported at the second international conference on "Cold Fusion" held at COMO in Italy. At that conference there were a number of papers from Italy, Japan, USSR and others confirming the results of F&P. The most important presentations were from Dr. Akito Takahashi of the University of Osaka and Dr. Eiichi Yamaguchi of NTT. Takahashi refined the technique of F&P whereby he was successful in achieving high D/Pd loading. He also investigated and used high/low periodic current whereby he was able to confirm not only the excess heat effect as claimed by F&P but also show the formation of helium in the electrode and obtained neutron spectra in the energy ranges predicted by theory. From US, Dr. John Bockris of the Texas A&M University reported tritium production about 10 greater than the background in a cell that ran for 760 hours. Dr. Thomson of the Rockwell International independently confirmed that the electrodes after electrolysis contained helium, an important bye product of the nuclear reaction. No helium was detected in the control non electrolyzed palladium. The most exciting results were reported by Yamaguchi of the NTT Labs. He adopted quite a different approach than electrolysis. He loaded deuterium in palladium plate specimen in vacuum, used an oxide (MnO) layer on one side as a barrier to outward deuterium diffusion. When the palladium was loaded up to about 60%, the other side of the palladium was coated with gold by sputtering. This set up was placed in a high vacuum chamber and the neutrons and the helium gas emission were monitored. He reported observing a burst of neutrons (1-2 million neutrons/sec), explosive evolution of gas, biaxial bending of the palladium plate and excess heat generation causing gold to alloy with palladium indicating a rise of temperature of the order of 800C. These observations were repeated in three separate runs. The neutrons were detected with a ALCOA TPS-451S 3He detector. In a later modified set up, programmed electric current was introduced to induce electromigration of the deuteron to subsurface narrow band. A burst of charged particles occurred after 130 minutes. Time resolved energy spectra indicated that the most likely reaction responsible for these particles was d + d = p (3.02MeV) + t (1.01 MeV), where p,d and t are proton, deuteron and tritium particles. The emission of the charged particles was confirmed with a solid state detector. Pd charged with hydrogen under the same conditions did not show any charged particle emission. However, these and other reports at the Como meeting did not have much impact on the outlook of the general scientific community. Early this year, Takahashi published a series of papers in which he reported very carefully conducted experiments. He not only confirmed reproducible generation of excess heat (power densities of 150 watts per cubic centimeter) but also tritium. He gave presentations at a symposium on the Non Linear Phenomena in Electromagnetic Fields, held on the 28th Jan, which was sponsored by the Japan Society of the Applied Electromagnetics. He also reported his work at MIT, and other institutions in US. To explain his results, he suggested a multibody nuclear reaction model. Dr. Yamaguchi of NTT, has also been reporting additional confirmatory results using his vacuum technique. In USA Storm from the Los Alamos and McKubre from SRI, made further careful calorimetric measurements and confirmed the excess heat data mentioned earlier. The results were reproducible. In those cases where there were variations, satisfactory explanations were given. All these positive reports generated fresh interest in the subject of cold fusion in the scientific community by the later part of the year. There was considerable anticipation at the third International Conference on "Cold Fusion", held at Nagoya on the 21-25 October. It was chaired by Professor H. Ikegami of the Osaka University. According to the conference organizers, 350 scientists from all over the world participated. More than 30 oral presentations including invited talks were made. In addition 133 posters covering research on excess heat (calorimetry), neutrons, charged particles, tritium, and models etc. were discussed in four sessions. Three panel discussions were held. Also in a small exhibition, IMRA R&D Co. Ltd and Tanaka Metals Company displayed their capability of the manufacture of palladium cathodes and other materials. The two companies have been supplying the researchers with "well", characterized electrode of PdAg and Pd-Ce alloys in various forms. The proceedings of the conference will be published by the Academic Press. In the following some of the salient results reported are summarized. Mechanisms and Models: Cold fusion is a complex phenomenon in which a "anomalous" nuclear reactions involving deuterons (or hydrogen) contained in a metal matrix such as Pd and Ti are supposed to be occurring at relatively low temperatures. The parameters which indicate a nuclear fusion reaction include the generation of excess heat, neutrons, helium, tritium, charged particles and radiations. The exact amounts and energies associated depends on the mechanisms involved, which at this point are not well understood. Until recently the there was almost an equal division of scientists. One group has been concentrating on the calorimetry to prove the generation of excess heat and the other looked for the nuclear products. What is necessary is to measure these parameters simultaneously and study their correlations as predicted by theory. The classical or normal fusion reactions include the following: 2) and 3) have high probability only in the hot fusion regime, Fleishman and Pon suggested that the following reaction_reported by Wallings and Simmons (J. Phys. Chem. 93, 4693, 1969) may be possible source of excess heat. d + d "He (76.0 kev) + photons/phonons (23.8MeV) 5) However, the occurrence of this reaction has small probability as it should be accompanied by high energy (23.8 MeV) gama rays. Schwinger Z. Phys. D, 15, 221, 1990) favoured the reaction p+d= He (5.35 keV) + photons/phonons (5.49 MeV) 6) Some groups have suggested other reactions to explain the products identified in their low temperature systems. For example, Takahashi reported to have observed in the electrolysis type of experiments not only slight peaks near the 2.45 MeV but one order of magnitude broad peaks at the 4-6 MeV in his time resolved neutron spectra. He postulated that in addition to reaction 2) and 3), the following multibody fusion reactions may explain some of his results: More recent work reported at this conference by Takahashi, involving Ti, Al-TiAl, Al-Ti, and Ti-Al alloy cathodes, and many variations of experimental parameters showed peaks at energies predicted by his multibody fusion model. At the conference a number of other mechanisms and models were presented. Some of the interesting ones included quantum electrodynamical coherent processes (Preparata), Dicke superradiance effect (Hagelstein MIT), quantum mechanical model (Chechin and Tsarev, Moscow), 'Natto' model (Matsumoto, Japan), dineuteron model (Jeifu Yang, China), a mechanism based on the reduction of the barrier penetration factor lamda due to electronic screening in solid metal under transient coherent flow of neutrons (Noriaki Matsunami, Japan), sono fusion (Kenji Fukushima, Japan), combined resonance tunneling in low energy d + d system allowing appreciable penetration through coloumb barrier(Xing Zong Li, China), fracto fusion (Norio Yabuchi, Japan), Surfdyne (Peter Gluck, Romania), Boson -in Boson -out model of Chub and Chub (Waber USA) and many others. It was difficult to evaluate the applicability of most of them, as all these were in the process of development. Only a few proponents, notably Takahashi, stated that their model was confirmed by the experimental results obtained in their labs. Excess Heat and Calorimetry: There were a large number of papers on the confirmation of the excess heat effect and improved calorimetry to measure unambiguously the thermal effect which could be attributed to a nuclear phenomenon. Unambiguous excess heat was reported using the following different approaches: Electrochemical: The experimental conditions used by F&P are fairly well known. They have shown that using a electrolytically deuterium loaded palladium-Ag cathode and an electrolyte consisting of a solution of L10D in D20, bursts of excess heat were observed at a constant current of 100 mA/cm2. Although in the early stages of their work reproducibility of such results was very unsatisfactory, at this conference they were able to demonstrate that it is possible to achieve this effect with a greater confidence. They showed a video in which four cells were being electrolyzed to a state that the electrolyte was boiling. From this they concluded that it was possible to generate excess enthalpy as high as 1 kW/cm3 in the temperature region of boiling point of the electrolyte. When asked about the causes of some of the failed experiments, Fleishman responded that the critical parameters were D/Pd ratio( which should be higher than .85), high current density (higher than 100mA/cm2) and a cathode free of microcracks. If these conditions are not met there is a great probability of poor or no heat effect. Professor Takahashi obtained reproducible excess enthalpy by pulse electrolysis using palladium cathode of configuration different from those used by F&P. A one mm thick 25 mm square palladium plate of high purity(99.99), supported by 2 polyethylene bricks and surrounded by a coil of platinum wire anode placed in a glass cell were used. The electrolyte was a solution of 3 mol L100 in D20. Using the same approach, Takahashi made calorimetric studies, in which current applied was in the saw tooth |