Possible radiation from thin film metal surface with anomalous excess heat: Can we observe hot spots or Bremsstrahlung?

Research Center for Electron Photon Science, Tohoku University, Japan ^ | June 2020 | J. Kasagi 1 , T. Itoh 1,2 and Y. Iwamura 1

[Kevmo]

Kasagi: Possible radiation from thin film metal surface with anomalous excess heat: Can we observe hot spots or Bremsstrahlung?

J. Kasagi 1 , T. Itoh 1,2 and Y. Iwamura 1

1 Research Center for Electron Photon Science, Tohoku University, Japan 2 Clean Planet Inc., Japan

In the ICCF21, we reported that no radiations with photon energy higher than 50 keV were observed associated with the excess heat generation in NiCuZr-H2 system. This means that the reaction does not produce energetic particles that undergo a secondary nuclear reaction with the material in the sample, nor does it produce radioactive nuclei. Then a question is ‘How is locally generated energy of above MeV transferred to the thermal energy of the sample?’

Here, we consider a naive situation in which the energy (Q) generated by the reaction is given to an extremely small region and is instantaneously transferred to kinetic energies of all conduction electrons there (the number of electrons is Ne). These electrons lose their energy by ionizing and exciting the substance during traveling a distance of the range (R), which may be a radius of a sphere of the hot spot. Then, the temperature of the hot spot rises by T = Q/MC (M: mass of the hot spot, C: specific heat capacity).

For a thin Ni foil with Q = 1 MeV, a hot spot is formed only for the case of 500 < Ne <1000; corresponding radius 38 > R > 16 nm and temperature 145 < T < 2150 K. When the excess heat is 1 W, hot spots are repeatedly generated in the sample at a rate of 6.3×1012 / sec.

Although very rough, 10-3 to 10-4 of the total number of Ni are included in a hot spot portion. Thermal radiation should be observed from the hot spot on the film surface. An energy spectrum expected for photon emissions from the thin film surface is shown in Figure.

Present are hot spots with T = 2000 K (red dashed-dotted line) and 300 K (red dashed line) at the ratio of (hot spot area) / (sample surface area) = 10−6 on the surface of a film at T= 700K (blue solid line).

One can say that if the temperature of the hot spot is high enough, visible light spectroscopy will reveal the presence of hot spots. When Ne decreases (electron energy increases), Bremsstrahlung emitted by electrons might be visible.

Figure also shows the expected Bremsstrahlung emission by 33 keV electrons generated when Ne = 30 (black dashed line). In the visible light region, the spectrum is not affected by the Bremsstrahlung at all. Thus, a measurement of keV region or higher is essential in order to clarify the presence of the Bremsstrahlung.

We have just begun to search for radiation associated with anomalous excess heat for a wide range of photon energies from eV (visible light) to keV (X ray). Radiation from metal film surface is a prime target.

[grey_whiskers]

Literally, “braking radiation”.

It occurs when an electron loses translational energy (”speed”) and dumps the energy in the form of a photon (light). I can no longer remember if it requires strict straight-line motion, or if the change of direction is also allowed.

[Kevmo]

Aqualung lyrics?

https://www.youtube.com/watch?v=Vw7OsMkqqiM