In this report, I assume the reader is familiar with Arata’s previous experiments. See his papers at LENR-CANR.org.
The new experiment uses a steel cell about 20 cm tall and 3 cm in diameter. (I do not have the dimensions in writing but I saw the cell.) A sample of zirconium oxide with palladium nanoparticles in (ZrO2*Pd) it is placed at the bottom of the cell. In some tests, an alloy of Zr*Ni*Pd is used. The cell is initially evacuated, and at room temperature. Highly purified deuterium gas is pressurized in an external tank to about 100 atm, and then injected into the cell in a high powered jet stream of gas, for about 10 minutes. The gas is in the jet stream is ionized and much of it is instantly absorbed by the material. Heat production begins immediately. The gas is not absorbed by the steel vessel walls. Heat production begins with a large burst lasting as long as the gas stream is injected. The temperature rises to about 70°C. Arata says this is caused by a combination of chemical and nuclear reactions. After the gas flow is shut off, the cell remains warm for 50 hours, gradually cooling. It would probably remain significantly warm for 100 hours, although they have not continued the experiment this long yet. During the second phase, the temperature in the center of the cell remains significantly warmer than at the outer cell wall, typically about a half-degree Celsius. This half-degree temperature difference remains about the same during the 50 hours of the run. Arata thinks that the heat from the second phase is entirely from a nuclear reaction. In one example, the first phase produced 4.4 kJ (at a rate of 18 kJ/hour, or ~5 W), and the second phase produced ~250 kJ (at ~4 kJ/hour, ~1 W). Much of the gas is absorbed by the Zr-Pd target. Gas pressure rises gradually after the flow is cut of, as the sample degasses. Helium is produced in the same ratio to the heat as with plasma fusion. However, the Zr-Pd sample has to be baked out after the run, to recover all of the helium. Three control experiments are described: * Hydrogen with the Zr-Pd target. The cell heats up in the first phase. After the gas stream is turned off, it cools down. There is no significant difference between the cell center and outer cell wall. Arata think the heat comes entirely from a chemical reaction. Helium is not produced. * Deuterium with no Zr-Pd. No heating effect or helium is observed. Gas pressure rises immediately in a straight line, and stops rising as soon as the gas flow is cut off. * Hydrogen with no Zr-Pd. The same result as with deuterium. Arata believes that highly pure deuterium is the key to success, and also, by the way, that helium contaminates the surface and must be removed in order to keep the reaction going. The DS-cathode configuration outer shell acted as a hydrogen purifier. The disadvantage was that it had to be heated to ~200°C with an auxiliary heater to allow the hydrogen to pass through the shell. In the latest configuration, Arata dispenses with that and uses pre-purified deuterium so that the cell can be operated starting at room temperature, without an auxiliary heater. The other advantage, not mentioned by Arata in this lecture, is that the nanoparticles of palladium do not sinter together as they did with Pd-black. The zirconium, which is 90% of the material, keeps them apart. A small electric motor is placed next to the cell, and powered by a thermoelectric generator that when there is a large temperature difference between the cell and ambient. Arata neglected to describe it during the lecture, although it was shown in a diagram. Apparently it is a proof of principle device. As far as I could tell, he neglected to mention several other details, such as the method of calibration, and the nature of the chemical reaction in the first phase. His lecture was difficult to follow, even for native speakers, so I may have overlooked something. Note that even without a calibration the comparison control experiments prove there is heat, but Arata has calculated the amount of heat (~250 kJ), so he must have done some sort of calibration. The high operating temperature, instant response and reliability of this device make it the most practical form of cold fusion yet developed. The small amount of palladium is also a major advantage. As far as I know, all of the tests with Zr-Pd targets and D2 have produced heat immediately and predictably. It may not be possible to turn off the reaction instantly, but this is no impediment to practical applications; it is not possible to turn off the heat from burning coal or uranium fission either. The reaction stops gradually as the sample degasses. It might be possible to force it to degas more rapidly, by raising the temperature and pumping out the cell. This is awkward without graphics, but to give an example of the reaction, in Fig. 5B (not shown here), room temperature is 24°C. A ZrO2*Pd sample with D2 begins phase 2 at 28°C and over 3000 minutes (50 hours) falls to ~26°C. A Zr*Ni*Pd with D2 begins phase 2 at a higher temperature, 32°C, but the temperature declines more rapidly at first, to ~26°C after 700 minutes, and thereafter to 25°C at 3000 minutes. A ZrO2*Pd sample with H2 begins phase 2 at 25°C (just above room temperature) and falls to room temperature after ~200 minutes, with no changes thereafter. As noted above, with the D2 samples, there is a persistent half-degree temperature difference between the center of the cell and cell wall, but no difference with the H2 sample. From this, I surmise that a 1 W heat flow produces a ~2°C temperature difference between ambient and the center of the cell, which is reasonable. There is no input power, so the signal to noise ratio is very high. (That is to say, laboratory grade equipment can measure a 2°C temperature difference with high confidence.) The cell is wrapped in insulation, as shown in the photo at LENR-CANR news. The graphs show that ambient temperature is controlled to within ~0.1°C. The facility is modern with laboratory grade HVAC, and first-class equipment, much better than most other Japanese national university labs I have visited. Arata has published a paper about this work, in Japanese (with an English abstract): Y Arata and Y. Zhang, “The Establishment of Solid Nuclear Fusion Reactor,” Kouatsu Gakkai (high temperature society) 2008. He provided a partial translation of that paper in English. Most of the details in this report are from the Japanese paper. I will upload this description of the experiment along with copies of the graphs in early June 2008. I am thinking of translating the entire Japanese paper. The day of this lecture, May 22, was Arata’s 85th birthday. There is no doubt that Arata is a genius, even though his lectures are, to put it politely, not well organized, and he is a character. As he often does, he passed out a book in Japanese listing his many honors and accomplishments, which include 70 patents, the first plasma fusion reactor in Japan, several major breakthroughs in welding and other high temperature industrial processes (essential to the Shinkansen and other major technology), dozens of awards including an international award in his name, a building named in his honor at Osaka National University, and the highest national award bestowed by the Emperor. I believe his collaborator Chang (sometimes transcribed Zhang) did the hands-on work in this experiment. She is assisted by three grad students from China. They seem highly competent but regrettably I did not have much time to speak with them or observe the experiment first-hand. - Jed