Optical Observation on Anomalous Heat Generationfrom Nano-sized Metal Composite
Takehiko Itoh1,2, Yoshinobu Shibasaki1,2, Jirohta Kasagi1,
Shouichi Murakami2, Mari Saito2 and Yasuhiro Iwamura1
1 Research Center for Electron Photon Science, Tohoku University, 982-0826 Japan
2 CLEAN PLANET Inc., 105-0022 Japan
E-mail: itoh@lns.tohoku.ac.jp

Abstract
We describe the first measurement of optical spectrum correlated with the anomalous excess heat generationfrom the NiCu multilayer foil with H2 gas. The method to induce the anomalous excess heat is the one we have beendeveloping: the anomalous excess heat occurs when a nano-sized metal composite film that has absorbed H2 is forcibly
evacuated and heated up for the gas to discharge. Spectra of the visible light of photon energy between 1.3 and 1.9 eV
were measured, in addition to the temperature measurement near the heater at the sample core, which has been
performed so far. Two types of samples, Ni plate and NiCu multilayer thin film, were examined under the conditions
in which the sample was in vacuum (without H2) and during desorption of H2 (with H2). It turns out that the measured
spectrum is understood as that of gray-body radiation. Surface temperature and radiant intensity of the sample arededuced from the spectrum. For the NiCu multilayer sample which shows anomalous excess heat that is evaluated only
from Tc, corresponding excessive radiant emission is clearly shown. Although the deduced quantities from the opticalradiation qualitatively follow the evaluated values of excess heat, it is indicated that more sophisticated analysis thattakes into account the radiation information is highly required for more reliable evaluation of the excess heat.
Furthermore, we discuss that the optical measurement plays an important role in the analysis of the heat burst event
observed during long-term observation. Our future experimental plans are also discussed.



1. Introduction
Recently, anomalous heat generation, producing much larger energy than ordinary chemical
reactions produce, has been reported in a system consisting of nanostructured metals (Ni, Cu, etc.)
and hydrogen (or deuterium) gas [1]-[3]. Such a system that produces a large amount of energy
without CO2 emissions is very promising as a future energy source; the realization of clean,
powerful and inexpensive energy will have a great social and economic impact.
We have been working on development of a new experimental method that emphasizes therole of hydrogen diffusion in nano-sized metal multilayer composite [4]-[6]. The method currently
under development is to induce a reaction of H2 (or D2) gas with the thin film layer structure of Ni
and Cu metal [4]-[6] instead of the composite amorphous metal powder developed in the joint projectof NEDO. We have already published some results using multi-layer foil with good reproducibility
suggesting anomalous excess heat generation [3]-[6], it is still necessary to develop experimental
equipment for new measurement which may provide more accurate and quantitative discussions.
In the previous measurements, the quantity of generated heat was evaluated only by the temperatureof the sample core although together with the radiation temperature of the surface was alsomeasured preliminarily.
Accurate excess heat measurement is highly required to discuss the phenomena morequantitatively, to clarify quantities that correlate with the energy generated, and, then, to explore
the mechanism. In this work, we describe the first experiment performed with an optical
spectroscopic measurement as the next step towards a more complete measurement.

15

2. Importance of optical measurement
Fig.1 shows a basic structure of a sample installed in a vacuum chamber; two sheets of Ni
plate coated with NiCu multilayer are placed on both sides of a ceramic heater (25mm square㸹MS-1000R; Sakaguchi E. H Voc Corp.) which has an R-type thermocouple (Tc) in the center. In
the previous reports, values of the excess heat were evaluated only by temperature measured Tc.
When the sample is heated up (typically between 700 and 900 Υ), the heat generated by the heater(and the excess one) becomes a heat flow and is transferred to the low temperature region by thethree processes as shown in Fig. 2; (1) conduction heat transfer through supporting rods (connectedwith the chamber wall) and wires of the heater and thermocouple, (2) radiation heat transfer fromsurfaces of heated element to the wall, and (3) convection heat transfer by gas. Since the pressurein the chamber is 110-4 Pa or less during measurements, the process (3) can be ignored. In
processes (1) and (2), the latter contributes most of the heat flow, because a large heat-insulating
substance (photveel) is used to support the sample. Thus, the measurement of radiant heat plays anessential role to improve the accuracy of excess heat measurement by measuring radiation.

Fig.1 Schematic of components around Nano-sized Multilayer Metal Composite.

16

Fig.2 Heat transfer path when a heat generation phenomenon occurs.
Spectroscopic measurements contribute to search for any transitions of special electronic
states that accompany the generation of excess heat [7]. In addition, it provides important
information on temperature and emissivity, even if it is a continuous thermal spectrum. As an
example of the latter, hotspot (local high-temperature region) observation is one of the challenges
we are pursuing as discussed at JCF20. Consider the case where a reaction that produces highenergy, such as a nuclear reaction, occurs in the sample as shown in Fig. 3(a). If the energy isdeposited to several to many electrons immediately after the reaction occurs, those electrons may
move in a random direction in the sample and lose their kinetic energies as shown in Fig. 3(b). Thisregion may locally form a hot thermal equilibrium, temperature much higher than that the region
heated up only by the heater. One can expect a radiation spectrum to have two temperaturecomponents (Fig.3(c)).

Fig.3 Schematic of energy distribution to electrons when energy is generated locally.
(a)Energy concentration in narrow space, such as a nuclear reaction, (b)Instantaneous generationof energetic electrons, (c)Low Energy Photon Emission due to energetic electrons173. Experimental procedure
The experimental apparatus is shown in Fig 4. A vacuum chamber is made of stainless steel
and the volume inside the gate valve is 4.6 litters. It is evacuated with a turbo molecular pumpdown to 3  10-6 Pa. The sample with the structure shown in Fig. 1 is set in the chamber. H2 gas
was introduced from the lower port (gas inlet) and its pressure were monitored by a Pirani gauge.
Heater input power is supplied by a DC power supplier with constant voltage mode. The voltage
and current values indicated by the device are monitored and those of independently measured arerecorded during the measurement.
The sample is placed at an angle of 45 degrees with respect to the direction of the center ofthe quartz window as shown in Fig. 4; this geometry enables us to put an X-ray detector behind the
Be window. The light emitted from the sample goes out through the quartz window, is focused on
the optical fiber by a focus lens, and is guided to the spectroscope (C10027-01; Hamamatsu
Photonics K.K.) that has a measurement range of 200-950 nm and a wavelength resolution of 2 nm.
In order to make the signal-to-noise ratio improve, we decided to obtain a spectrum that averaged
50 measurements with an exposure time of 1 second.
In the present work, we measured two types of samples: (1) nanostructured Ni-Cu
multilayer film deposited on a Ni plate and (2) Ni plate (each side of 25 mm and a thickness of 0.1mm) which is used as a substrate. For the Ni-Cu multilayer film, Cu and Ni are alternately deposited
6 times each on the substrate by the sputtering method. By this way, the sample with a laminated6-layer structure of 2nm-Cu and 14nm-Ni is prepared. The Scanning Transmission Electron
Microscope (STEM) image of the sample structure is shown in Fig. 5.

Fig.4 Schematic of Experimental apparatus.

18

Fig. 5 Scanning Transmission Electron Microscope (STEM) Imageof Cu-Ni Multilayer Thin Film.
The present experiment has been carried out as follows.
(1) Setting sample: Two sheets of sample are fixed on both sides of a ceramic heater and placed at
the right position in the vacuum chamber, which is evacuated for a vacuum bake-out. After about 3days baking out, the heater is turned off.
(2) Measurement without H2 gas: In a vacuum condition (i.e., without H2 gas introduction), thevoltage of the power supply of the heater is set at various values (between 20 and 48 V) andmeasured are the temperature inside the heater (Tc) and the optical spectrum. These are regarded
as the reference data corresponding to no excess heat.
(3) Measurement during desorption of H2 gas: The sample absorbs H2 gas by filling the chamberwith H2 gas to 200-300 Pa and keeping the temperature at about 250 Υ for 12 -15 hours. At thesame time as setting the heater input voltage to the value of the measurement condition, theevacuation of the vacuum chamber is started. The sample temperature (Tc), chamber wall
temperature, heater input voltage and current, and vacuum chamber pressure are read and recorded
every second. In addition to this, optical spectral measurements in the visible light region are taken
every 5 to 30 minutes and saved as data. Data collection continues for at least 6 hours after thevoltage once set, since H2 desorption is expected to continue sufficiently. For measurement under
different conditions by changing the set voltage, return to the beginning of (3) and start from H2absorption.

4. Results and Discussion
As discussed in Section 2, the heat, including the one from heater and the other generated
by reactions between the sample and the H2 gas, is dissipated as a heat flow from the sample: aradiant heat transfer and a conduction heat transfer. However, the present experiment cannot be acomplete measurement of above quantities because of a narrow and limited wavelength range of
optical radiation. Thus, discussing more accurate values of excess heat must wait for future
experiments. Here, we show the optical spectrum newly introduced, and discuss its change as theexcess heat was produced.
Fig.6 shows simple estimates of excess heat from (a) the NiCu multilayer sample and (b)the Ni substrate sample. Each dot against the elapsed time represents the input power of the heater(black dot) and the excess power (orange dot). The time regions without dots correspond to thetime for the sample to absorb H2 gas. Note that the evaluation of the excess heat is based only on
the temperature Tc as reported in our previous reports [3-6], and is not a quantitative evaluation with19

the addition of radiant heat flow. As seen in Fig.6, excess heat of about 2 s1 W is observed for
the NiCu multilayer sample, while for the Ni plate, almost no excess heat is detected.

Fig. 6 Excess heat and Input power.
(a) Experiment with NiCu Multilayer Thin Film on Ni plate,(b) Experiment with Ni plate.
Fig.7 shows intensity spectra of emitted light photon with energy above 1.2 eV from the
NiCu multilayer sample: the sample clearly shows the excess heat generation as indicated in Fig.6.
The vertical axis corresponds to the radiation energy observed per second (i.e., photon energy times
number of photons /sec). In the figure, the spectrum measured during H2 desorption (red dot) andthat without H2 (blue dot) for heater input power of 21, 27 and 35 W are compared.
The first point to be emphasized is the fact that the radiation intensity is clearly increased
by desorption of H2 as compared without H2. This is a clear indication of the excess heat: the greater
the amount of heat, the greater the brilliance. That is, it is shown that the radiant energy is increased
by increasing the temperature of the sample surface due to heat generation. Moreover, the amountof yield increases as the input power increases. This is different from the behavior of excess heatin Fig.6. This indicates that more sophisticated analysis that takes into account the radiation
information is highly required in order to obtain accurate value of the excess heat.

20

Fig. 7 Photon emittion from NiCu Multilayer Thin Film.
Second, the measured spectrum is well understood as the gray-body radiation, at least in
this energy region. Since the photon energy ε we measure is much larger than the radiation
temperature (ε >> kTs), Planck's radiation equation can be approximated as follows.
# = ~ •• • exp (-•/kBT)
Y( ) = ! "
*
$%&'

+,

-.#

The solid curves in Fig.7 are the best fitting curves calculated to explain the experimental
data with 3 parameters under the assumption that the emissivity of the sample does not depend onenergy. We used the following approximate function for the intensity Y(e):$Y(ε) = A• • exp "− * + , ,(1)%&'

where A is the normalization factor, e is photon energy, k is the Boltzmann constant, Ts is thesurface temperature of the sample and C represents the background yield due to the dark current of
the device: the 3 parameters are A, Ts and C. In this way, the important values A and Ts can beobtained: the total (integral) radiation power from the sample is proportional to ATs4, if theemissivity is a constant. The radiant power mentioned below refers to the ATs4.
Figure 8 shows a comparison of the emitted radiation from the two samples. Fig.8 (a) and(b) show the radiant power and the surface temperature, respectively, obtained for the NiCu
multilayer film, and Fig.8 (c) and (d) show those for the Ni plate sample. Red circles correspondto the foreground experiment with H2 storage, and open circle to the reference experiment without
H2.
The comparison of (a) and (c) in Fig.8 shows more clearly that the NiCu multilayer sample
generates a large amount of excess heat as compared with the Ni plate sample. In the NiCu
multilayer sample, the radiant power during H2 desorption is always higher than without H2,demonstrating the presence of the excess radiation which increases as the input power increases.
In the Ni plate sample, on the other hand, no significant difference is observed; i.e., no excess
radiation in the Ni plate. The same behavior can be clearly seen in the comparison of (b) and (d) in21

Fig.8. Observed temperatures, both Tc and Ts, are always larger during desorption of H2 for the
NiCu multilayer sample, while no change in temperature for the Ni plate sample.

Fig. 8. Comparison of emitted radiations between NiCu Multilayer Thin Film on Ni Plate and Ni
Plate. (a) Radiation Power and (b) Temperature of experiment using NiCu Multilayer
Thin Film (c) Radiation Power and (d) Temperature of experiment using Ni Plate.

When the H2 desorption experiment with the NiCu multilayer sample was conducted forseveral hours continuously, a phenomenon in which Tc rises suddenly did occur as reported in[4,5,8]. We call it heat burst. Fig.9 shows two such events observed simultaneously withmeasurements of optical spectra, for the first time. As seen in Fig.9 (a) where heater temperature(Tc) is plotted against elapsed time, the heat burst events are recorded at 8.5 and 22 hours after thestart of the experiment. Fig. 9 (b) shows corresponding excess heat evaluated based solely on Tc.
The surface temperature (Ts) and integrated yield between 1.2 and 1.5 eV (proportional to radiantintensity) deduced from light spectrum are shown in Fig. 9 (c). The bump structures corresponding
to those of Tc are clearly confirmed in both Ts and the radiant intensity. However, the data were
not obitained immediately before and after the bump, since the number of sampling of the opticalmeasurement is small for the elapsed time after 15.5 h. Fig.9 (d) and 9 (e) show the spectra before
and after the first burst and the second burst, respectively.
One may interpret the time sequence of the bump events observed in Fig.9 as follows: A
heat burst occurs locally on the surface of the NiCu multilayer sample, part of the power isdissipated immediately from the surface as the radiant power, and at the same time, the generated
heat is transferred to the core of the sample, then, temperature Tc raises. It is considered thatinvestigating the heat burst in more detail, for example, to obtain precise time correlation between

22

the busts in Tc and in the radiant power, might lead to the elucidation of the mechanism of theexcess heat generation.

Fig. 9 Simultaneously detection of Heat Burst by Radiation of spectrometer Looking at theSurface of the Multilayer Thin Film and a Thermocouple Located in the center of Heater.
(a)Heater Temperature and Input Power, (b)Excess Heat, (c) Surface temperature and Radiation
Power by Spectrometer, (d)Radiation Spectrum of 1st Heat Burst, (e) Radiation Spectrum of 2nd
Heat Bust.

5. Future Plan
In the present experiment, we were able to observe the anomalous heat generation
phenomenon from the observation of radiation, although the observed region is very narrow as 1.31.9 eV. Also, we discussed, in Section 2, the importance of the radiation measurement to explore
the mechanism of the anomalous excess heat. Thus, it is natural to extend the region of the
wavelength to be measured. This is our future plan as a next step.
In Fig.10, calculated spectra of the black-body radiation are shown for temperatures from
800 to 1100 K, expected temperatures in our experiments. Shown in the lower part of Fig.10 are
the detectable energy regions of the detectors under consideration. Since region 1 is alreadyintroduced in this work, we will extend our measurements to low energy regions using a nearinfrared spectrometer (1.1-2.5 μm) and a mid-infrared detector (3-5.6 μm). It is expected, then, tograsp the whole picture of the radiation: This is equivalent to a sophisticated calorimetermeasurement, and the reliability of the excess heat is dramatically increased.
In addition, in order to elucidate the mechanism related to the existence of hot spots, it isnecessary to measure the visible light region on the high energy side more carefully. We are also
considering ways to reduce the effects of radiation and improve S/N for measurement in higher
energy side of region ձ

23

Fig.10 Extended spectra; from Visible light to infrared.

6. Summary
In the present work, we aimed to improve the accuracy of measurement of the anomalous
excess heat generation observed in Ni-hydrogen system by adding optical measurement to theconventional measurement system. This is the first measurement of optical spectrum correlatedwith the anomalous excess heat generation from the NiCu multilayer sample with H2 gas.
In the experiment with the Ni substrate sample, the temperature and radiation intensity
deduced from the light spectrum hardly changed before and after hydrogen absorption, but with
the NiCu multilayer sample, they showed clearly excessive radiations.
The heat burst phenomenon was observed multiple times in the measurement with the NiCu
multilayer sample. When heat burst phenomena occurs, sudden increase in the radiation intensity
together with the surface temperature was observed at the same time as the heater temperature
increases.
In conclusion, we have constructed the measurement system for the optical spectroscopy
by adding the previously used one. The optical measurement is found out to be an important one
for the study of anomalous excess heat generation. Although the deduced quantities from the opticalradiation qualitatively follow the evaluated values of excess heat, it is indicated that moresophisticated analysis that takes into account the radiation information is highly required for morereliable evaluation of the excess heat.

Acknowledgements
This work is partially supported by CLEAN PLANET Inc. The authors acknowledge also themembers of CLEAN PLANET Inc., Mr. H.Yoshino, Mr. S.Hirano, Mr. T.Takahashi, and Mr.
H.Shimokawa, for their significant assistance.





24

References[1] A. Kitamura, A. Takahashi, R. Seto, Y. Fujita, A. Taniike and Y. Furuyama, “Effect of Minority

Atoms of Binary Ni-Based Nano-Composites on Anomalous Heat Evolution under Hydrogen
Absorption”, J. Condensed Matter Nucl. Sci., 19 (2016) 1-10.
[2]A. Kitamura, A. Takahashi, K. Takahashi, R. Seto, T. Hatano, Y. Iwamura, T. Itoh, J. Kasagi,
M. Nakamura, M. Uchimura, H. Takahashi, S. Sumitomo, T. Hioki, T. Motohiro, Y. Furuyama,
M. Kishida, H. Matsune, “Excess heat evolution from nanocomposite samples under exposure
to hydrogen isotope gases”, International Journal of Hydrogen Energy 43 (2018) 16187-16200.
[3]Y. Iwamura, T. Itoh, J. Kasagi, A. Kitamura, A. Takahashi, K. Takahashi, R. Seto, T. Hatano,
T. Hioki, T. Motohiro, M. Nakamura, M. Uchimura, H. Takahashi, S. Sumitomo, Y. Furuyama.
M. Kishida and H. Matsune, Anomalous Heat Effects Induced by Metal Nano-composites andHydrogen Gas, J. Condensed Matter Nucl. Sci. 29 (2019) 119-28.
[4] Y. Iwamura, T. Itoh, J. Kasagi, S. Murakami and M. Saito, “Excess Energy Generation using a
Nano-sized Multilayer Metal Composite and Hydrogen Gas”, J. Condensed Matter Nucl. Sci.
33 (2020) 1-13.
[5]S. Murakami, T. Itoh, Y. Iwamura, M. Saito and J. Kasagi, “Excess Energy Generation
Experiments using a Nano-sized Multilayer Metal Composite and Hydrogen Gas”, Proceedingsof the 20th Meeting of Japan CF Research Society, JCF20, December 13-14, 2019, Reference
Hakata Eki-Higashi Rental Room, Fukuoka, Japan p.86-96.
[6]M. Saito, T. Itoh, Y. Iwamura, S. Murakami and J. Kasagi, “Elemental Analysis for Elucidationof the Anomalous Heat Generation Phenomena”, Proceedings of the 20th Meeting of Japan CF
Research Society, JCF20, December 13-14, 2019, Reference Hakata Eki-Higashi Rental Room,Fukuoka, Japan p.74-85.
[7]J.kasagi, “Possible radiation from thin metallic multilayers with hydrogen-permeatedanomalous excess heat: Can we observe hot spots or Bremsstrahlung?”, Abstract of ICCF22 813 Sep,2019 Assisi Italy p.10
[8] Y. Iwamura, T.Itoh, M. Saito, S. Murakami and J. Kasagi, “Evidence for Surface Heat Release
Reaction over Nano-sized Multilayer Metal Composite with Hydrogen Gas”, Proceedings of the21th Meeting of Japan CF Research Society, JCF21, to be published.

25