Osaka National University Prof. emeritus Yoshiaki Arata gave a lecture and demonstration of his latest cold fusion reactor on May 22, 2008, in Arata Hall on the university campus. (Note that Arata Hall is named after Prof. Arata, who is one Japan’s leading scientists, with honors including a building named after him at the university, and an award from the Japanese Emperor in 2006.)
Highly purified gas is held at 100 atm in the tank shown on the left. The cell has a sample of zirconium with palladium nanoparticles (ZrO2 or a Zr-Ni alloy, both with Pd particles). The sample weighs 7 to 18 g. The cell is equipped with two thermocouples: Tin (inside, at the core of the Zr-Pd sample), and Ts (at the surface of the cell wall). The cell is insulated.
The cell is first evacuated and baked out, to purify the Zr-Pd sample. After the cell cools from the bake-out, either deuterium or hydrogen gas is injected into the cell at high pressure, causing it to ionize. The ionized gas rapidly enters the Zr-Pd sample. A chemical reaction occurs, heating up the sample.
Figure 3 shows what happens after the sample is saturated with gas and it begins to cool down from the burst of chemical heat. This phase of the experiment begins at about 300 minutes. Arata calls it the “skirt fusion zone” phase. This graph shows data from three test runs:
A ZrO2-Pd sample with D2 (deuterium) gas.
B Zr-Ni-Pd sample with D2 gas.
C ZrO2-Pd sample with H2 (hydrogen) gas.
Two temperatures for each test are shown. These are from the two thermocouples in Fig. 2, Tin (inside the cell) and Ts (at the cell surface).
Tests A and B both produce heat, remaining hot 3000 minutes (50 hours) into this graph, and beyond up to 100 hours. Test C, with hydrogen, cools down to room temperature at 500 minutes. This shows there is a difference between hydrogen and deuterium. A mass spectrometer shows that helium proportional to the heat is produced during tests with deuterium. With hydrogen, no heat is produced during this phase, and no helium is produced.
With deuterium, the inside of the cell remains hotter than the cell wall which shows that the heat originates in the Zr-Pd material. With hydrogen, there is no temperature difference.
Note that the ZrO2-Pd (Test A) does not get as hot initially as the Zr-Ni-Pd (Test B), but it remains hotter after 500 minutes.
Rothwell and Storms have published a review of this experiment criticizing the calorimetry, mass spectroscopy and some other aspects of the work. See: Rothwell, J. and E. Storms, Report on Arata’s Paper and Lecture about his “Solid Fusion” Reactor. 2008, LENR-CANR.org.