Randy Davis Patents/Marathon, and New Energy Power Systems

An earlier post ended by saying "The work by Safire, Aureon Energy appears to involve high voltage ionization of hydrogen and deuterium gas. It is not of interest with regard to LENR and cold fusion." The same type of comment can be applied to information in patent application US2021/0151206A1, "Apparatus and Method for Sourcing Fusion Reaction Products," May 20, 2021, as it generally involves using a high voltage to accelerate deuterium ions towards a deuterium target, i.e., rather than producing LENR and cold fusion reactions.

Previous posts have discussed items # a, b, c, and j from the list of example system concepts and parameters. The list was posited as something that could be included in funding proposals. Item # f from the list of example system concepts and parameters is about reaction material (cathode) temperature. Does the design in patent application US2021/0151206A1 include an electronic controller to maintain reaction material in the cathode above its Debye temperature? Same question regarding Safire/Aureon Energy and the lattice energy converter (LEC). An electronic controller can be designed to maintain cathode reaction material above its Debye temperature (e.g., about 200 ^oC for nickel), where maximum lattice oscillator frequency is reached. Below this temperature, all possible modes of lattice vibration are not excited and quantum mechanical effects can be effective. Above the Debye temperature, however, a gaseous electrolysis cell can be expected to operate consistently. Also, at 300^oC, protium diffusion in nickel occurs at approximately the same rate (i.e., 2.0 x 10^-6 cm²/sec) as diffusion of deuterium or hydrogen in palladium at 100^oC, permitting comparison of gas/gaseous designs with liquid electrolysis devices operating at lower temperatures. This rate is ten times the rate of deuterium or hydrogen diffusion in palladium at room temperature.

It is of interest in terms of industrialization potential now also to look at some of the ideas behind lattice confinement fusion (LCF) being developed under NASA’s Advanced Energy Conversion (AEC) project. LCF is discussed more thoroughly in another LENR-forum.com thread. Reference the paper, “NASA GRC Hosts Lattice Confinement Fusion Virtual Workshop,” by Theresa L. Benyo et al., regarding an LCF workshop on May 21, 2020. This paper indicates that the project was initiated in February 2017. LCF is based upon the idea that deuterons can be disintegrated by high energy (>2.22 MeV) gamma radiation. It doesn’t involve cold fusion reactions. By comparison, the lattice energy converter (LEC) developed by Frank Gordon et al. from SPAWAR is about cold fusion. A description of LCF can be divided into three sequential steps. First, deuterium is loaded into a metal absorber such as titanium or erbium. This is possible due to a small, regularly spaced lattice structure for these metals, where deuterium ions can be held. Since the atomic mass of erbium is 167.26 and its density is about 9 grams/cm³, one cubic centimeter can be expected to contain 3.2 x 10²² erbium atoms. Likewise, since the atomic mass of titanium is 47.8 and its density is 4.5 grams/cm³, one cubic centimeter can be expected to contain 5.6 x 10²² titanium atoms. The density of deuterium might be expected to be about 10²³ atoms/cm³, or several times the number of metal atoms. Gamma radiation with energy greater than 2.22 MeV is able to cause deuterons in the absorber to disintegrate into protons and neutrons by an effect that was first discussed in1934 by J. Chadwick and M. Goldhaber in “A Nuclear Photo-Effect: Disintegration of the Diplon by Gamma-Rays”. The gamma radiation can be produced by several methods. One of these is with an electron accelerator, where bremsstrahlung gammas are produced as the electrons are slowed down in a metal target. Nuclear cross section for (gamma, deuterium) reactions is listed as 0.001 barn (10^-27 cm²) in the “Handbook on Photonuclear Data for Applications: Cross Sections and Spectra,” IAEA-TECDOC-1178, published by the International Atomic Energy Agency in 2000. The protons and neutrons that are produced will each have about 240 keV of kinetic energy. With regard to this step, it will be important for the total energy produced by the LEC to be greater than, e.g., energy expended in loading deuterium into the absorber plus energy required by the electron accelerator. In the second step, the neutrons produced by gamma disintegration are envisioned to scatter against atoms of the metal absorber and against deuterons in the absorber. Neutron scattering against deuterium is considered to be an elastic process; neutron velocity is moderated with about half of the energy given to a deuteron. Scattering of the neutrons with about 240 keV of kinetic energy against deuterons is envisioned to produce “energetic” deuterons with enough kinetic energy (velocity) themselves to fuse with other deuterons in the absorber. This is believed to be made possible by significant screening of the deuteron’s positive charge by electrons in the absorber (an effect that might also be evident for targets in standard d,d neutron generators). The second step is envisioned as “a new and unforeseen means of initiating fusion and other nuclear reactions”. The paper on the LEC workshop indicates that with an electron screening potential of 1.9 keV, the fusion cross section for 120 keV deuterons can be assumed to be 10^-5 barn or better. The fusion reactions can produce He3 and neutrons, and also T3 and protons in about equal amounts. These have millions of electron volts (MeVs) of kinetic energy that, by scattering in the absorber, can potentially result in useful heat. In the third step, neutrons having 240 keV of energy (and neutrons with higher energy) are envisioned to be absorbed into the metal atoms, producing isotopes of the metals with higher mass. Protons having 240 keV of energy (and protons with higher energy) are envisioned to be absorbed into the metal atoms, producing elements with higher atomic number. This is envisioned to be supported by screening of the proton’s positive charge by electrons in the absorber.

The above post on lattice confinement fusion (LCF) being developed under NASA’s Advanced Energy Conversion (AEC) project mentions two reaction cross sections: the first for photodisintegration of deuterons by gamma rays (0.001 barn or 10^-27 cm²) and the second for fusion from 120 keV deuterons (assumed to be about 10^-5 barn or 10^-9 cm²). Methods to use cross section calculations are discussed in nuclear physics textbooks (e.g., Section 5-4 in “Elements of Nuclear Physics,” by Walter E. Meyerhof, McGraw-Hill, Inc., 1967). Cross section for photodisintegration of the deuteron is discussed on pages 608-613 in Section D, Chapter XII of “Theoretical Nuclear Physics,” by John M. Blatt and Victor F. Weisskopf, John Wiley and Sons, 1952. The paper by Chadwick and Goldhaber in 1934 was followed by one the next year that calculates cross section determined experimentally for deuteron disintegration by 2.6 MeV gamma rays from radium (see “The Nuclear Photoelectric Effect,” Proceedings of the Royal Society, vol. A151, pages 479-493, 1935). In their experiment, about 4.80 x 10⁶ gamma rays per hour per cm² were allowed to pass through a chamber that contained 10²² deuterons. This resulted in the production of only 30 reactions per hour. Chadwick and Goldhaber determined the cross section to be about 6.6x10^-28 cm² (0.0007 barn). The cross section for fusion from 120 keV deuterons (10^-5 barn or 10^-29 cm²) came from a graph in the paper, “NASA GRC Hosts Lattice Confinement Fusion Virtual Workshop,” mentioned in the above post.

Quote from Gregory Byron Goble

with no reaction products but with energy deposited directly into lattice as phonons. A related transmutation theory claims that shock waves can be used to initiate a self-densification process, which creates a "neutron soup" that allows for transmutation.

The third type admits the conventional hot fusion nuclear reactions by claiming that a very-low energy resonance in the cross section exists, which also suppresses radiation signatures.

That's the Army thinking way back in 2010...

But, ... in the 2nd step of the LCF process, the fusion reactions would result in He3 and neutrons, and also T3 and protons in about equal amounts. These have millions of electron volts (MeVs) of kinetic energy that, by scattering in the absorber, can potentially result in useful heat.

Quite a bit of scale-up will be needed. Each of the (d,d) fusion reactions in the second LCF step should provide 3-4 MeV of energy, or 5.6x10^-13 joule (1 MeV = 1.6x10^-13 joule). Since 1 watt = 1 joule/sec, a 10 kW system would need to produce about 1.8x10¹⁶ reactions/sec.

Or according to Leif Holmlid's work we would have to generate 1.8 x 10^16 negative muons per second for your 10 kW system. Or could this generate Mega Watts? Seriously, we just don't know!

Please note in post #305 above, that 10^-5 barn is 10^-29 cm² (rather than 10^-9 cm²).

“Cross section” is a means to express probability of reaction for a single target nucleus, among many target nuclei available and presented to an incoming beam of particles or gamma rays. It concerns the probability of a single nuclear reaction. From the standpoint of the incoming beam of particles or gamma rays, the probability of reaction is equal to the number of particles/photons that have produced reactions (e.g., 30 in the paper by Chadwick and Goldhaber) divided by the total number of incoming particles/quanta (e.g., 4.8x10⁶ per cm²). From the standpoint of the target nuclei, the probability of reaction is equal to the number of target nuclei (e.g.10²²) multiplied by the cross section for an individual nucleus (6.6x 10^-28 cm²) divided by the total area exposed. The above post on Lattice Confinement Fusion (LCF) has 10²³ target atoms per cm³, and cross section for the first step of photodisintegration is about 10^-27 cm² (0.001 barn). Thus, about one gamma ray out of 10,000 might be expected to be able to disintegrate a deuteron to produce a neutron for the second step of the process.

The reader might have an idea on where these calculations are headed. It is very important that the calculations be verified. The above posts on Lattice Confinement Fusion (LCF) indicate 10²³ deuterium target atoms per cm³. The cross section for the second step of d,d fusion is about 10^-29 cm² (10^-5 barn). Thus, in the second step of the process, about one neutron out of 10⁶ neutrons might be expected to be able to cause fusion. Since a 100 watt/cm³ system would need to produce about 1.8x10¹⁴ fusion reactions/sec/cm³, the number of neutrons that would be required for the second step might be expected to be 10⁶ times this, or 1.8 x 10²⁰ neutrons. Then, the number of gamma rays that would be required for the first step might be expected to be 10⁴ time this, or 1.8 x 10²⁴ gamma rays, each greater than 2.22 MeV. A 10 kW system would need to have a cathode composed of 100 cm³.

The above post indicates that the number of gamma rays required for the first step might be expected to be 1.8 x 10²⁴ gamma rays, each greater than 2.22 MeV. Since 1 MeV = 1.6 x 10^-13 joule, energy of all of the incoming gamma rays would total 6.4 x 10¹¹ joule/second or 6.4 x 10¹¹ watts (i.e., in order to obtain 100 watts in one cm³ of reaction material) !! It is clear that additional information is needed to understand the NASA LCF program.

What additional information is needed? Empirical evidence of a working fission-fusion reactor?

Left LF KAIST answer 2009, right LF NASA neutron plot 2022 - not exactly the same.

Dr. Richard ask for an indication of additional information that is needed. One of the things that comes to mind is that cross sections for photodisintegration of deuterons (vs. 10^-3 barn) and for fusion of 120 keV deuterons (vs 10^-5 barn) need to be validated. The valiated values should then be plugged into the above calculations to see if they can be improved.

Post #305 above indicates that Chadwick and Goldhaber in 1934 detected 30 photodisintegrations from 4.8 x 10⁵ gamma rays with a sample of 10²² deuterons. The above graph from Ahlfors indicates about 500 reactions in 6 hours, probably with a sample of. 10²³ deuterons.

Already posted elsewhere

NASA has indicated that perhaps neutrons from the 2nd LCF step could be used to fission natural or depleted uranium-238. In a general sense, the fission process can be expected to produce about 200 MeV per fission. Thus, for the same energy output, only 10^-2 (1/100) of the input energy would be needed.

Thanks, Ahlfors. A nuclear engineer familiar with performing cross section calculations is needed to check the calculations in post #312-313. Wish Bob (Robert) Smith from OIC were still alive!!