cffuture1 home page: LENR Cold Fusion Process

The LENR Cold Fusion Process

Unraveling the cold fusion/LENR puzzle is an exciting challenge. LENR cold fusion appears to be the concurrent operation of 2 processes: Process A is a reaction between 2 nuclei at room temperature, Process B is the dissipation of large amounts of nuclear energy without production of energetic particles. Process A poses problems because the diameter of the nucleus is only 1/100000 as large as that of the atom. The nuclear force is a contact force. The 2 nuclei have to touch each other before reaction can occur. The electrical force keeping the nuclei apart is very large when contact is approached. It cannot be overcome by the normal processes of quantum chemistry. Process B actually poses a harder problem for theorists than Process A.

In ordinary nuclear physics the energy released during reaction breaks apart the product nucleus in almost all cases, and when the product nucleus does not break apart, the energy is released as a high energy gamma ray. Most proposed cold fusion theories have addressed only Process A. Most have used abnormal enhanced electron screening to reduce the energy required for nucleus-nucleus contact. There is one generally accepted cold fusion process that is explained in this way. It is called muon-catalyzed fusion. It was discovered and modeled back in the 1950s. The negative muon is a short-lived heavy version of the normal electron, and is a constituent of cosmic rays. It is easily captured by a hydrogen molecule, and then forms a new type of hydrogen molecule 200 times smaller than the normal one. This enables the muon's negative charge to get much closer to each nucleus. Deuterium-containing versions of these micro-molecules undergo fusion. But there is also a copious production of high energy nuclear particles, in violation of Process B. (The negative muon is unstable, and its use does not seem to provide a road map to practical nuclear power.)

Fortunately for cold fusion enthusiasts there is another strategy that overcomes the nuclear repulsion roadblock. This alternate strategy does not involve improved electron screening. Instead, it reduces the effective electrical repulsion force between paired nuclei by quantum mechanically partitioning the hydrogen nucleus. Quantum mechanical partitioning occurs when a hydrogen nucleus transitions into a wavelike stationary state in the form of a time-independent standing wave occupying a large number of potential wells. This partitioning allows both deuterium cold fusion and a variety of nuclear transmutations to take place. It also sets the stage for the radiationless heating of a metal by the nuclear reaction energy.

How does the partitioning strategy work? It is not part of quantum chemistry as we understand it, and it is not part of normal solid state physics. So how can it occur? The best way of understanding it is to look at some of the exciting new results in superfluid physics. The part of superfluid physics that is the best teacher is the study of Bose-Einstein condensates in optical lattices. Here, the setting is very different from that encountered in cold fusion, but the basic physics has much in common. An important paper was published by Jaksch et al. in 1998 in Physical Review Letters. This paper modeled a distribution of polarizable neutral atoms in an optical lattice. A type of Rb atom has been used in laboratory studies. Such atoms are neutral, but become polarized into an electric dipole when subject to an electric field. An optical lattice is a region of space containing an intense standing wave of light created by the simultaneous presence of 2 or more laser beams of almost the same frequency. The light beams are intensified between mirrors, which builds up standing waves. A 1dimensional optical lattice when combined with a 2-dimensional magnetic trap produces a sequence of small volumes within each of which there is an intense electrical field, and between which are small volumes containing weak or near zero-intensity field. When polarizable atoms are very cold and near absolute zero temperature, they are attracted to and can be made to settle into the small volumes of intense electric field. The Jaksch et al. paper modeled configurations which had the periodic symmetry of the optical lattice. The authors showed that when the electric field intensity is strong and the potential wells seen by the atoms are deep, the only physical solution with periodic symmetry is to have a whole number of atoms in each potential well, i.e., the well occupation numbers are either all zeros, or all ones, or all twos, etc. But when the electric fields are weak and the potential wells shallow, the atoms configure themselves so as to have a fraction of each atom in each potential well. The deep well picture corresponds to a so-called "Mott insulator", which simulates normal chemistry. In normal chemistry a hydrogen nucleus sits in a potential well in an interstitial location in the metal lattice, and undergoes thermal vibrations. When the temperature is raised, the vibrational amplitudes become larger and it becomes possible for the hydrogen nucleus to "jump" to a neighboring unoccupied site. This "jumping" is the mechanism of normal diffusion in a metal. When the potential wells are shallow, the physics is different. If the well is sufficiently shallow, the particle becomes wavelike and expands into neighboring vacant sites even at low temperature. When a number of atoms expand within the same volume, they merge. The resulting composite is a superfluid. It is a single fluid mass which dilutely fills the whole accessible volume. There is then a fractional part of each participating atom in each potential well.

So the alternate cold fusion strategy is to create a hydrogen superfluid in a metal crystallite at room temperature. This seems to be the strategy that works, and the one that was accidentally discovered by Fleischmann and Pons in their pioneering cold fusion studies. It works because suitable metal crystals provide a periodic array of shallow potential wells within which deuterons can condense as a "superfluid", and because each deuteron when in the partitioned superfluid form has only a fraction of its nuclear charge in any one potential well. Moreover, this fraction can be very small, sometimes maybe only one millionth of its normal charge. It looks almost like a neutral particle. At such a low charge fraction the deuteron can even share volume with the nucleus of a heavier atom that gets in its way, which makes transmutation possible. Sharing volume with another wavelike deuteron is easier, and results in cold fusion.

Let us focus on the deuterium fusion process. Consider how the partitioning strategy accomplishes Process B. Partitioning's primary effect is to block high energy particle emission. When a wavelike deuteron combines with another wavelike deuteron, the wavelike product cannot split apart and release high energy particles for the following reason. High energy particle and gamma ray emission can only occur when a nucleus sits fully localized in a single location, i.e., within a single potential well. When 2 wavelike deuterons fuse, symmetry preservation requires that the immediate product be wavelike helium with the same periodicity as the initial deuterons. The nuclear reaction energy is also partitioned and made available only at a large number of equivalent points in the lattice. If the nuclear product were to break apart, preservation of symmetry would require that the fragments be wavelike and conform to the periodicity of the metal lattice. This means that the quantum mechanics wavelength of the wavelike fragments must match the lattice spacing of the metal. Such long wavelengths are precluded by the large amount of momentum that must be carried by the energetic fragments. Therefore, energy release by high energy particles is forbidden. Gamma ray energy release is also forbidden. A gamma ray containing the reaction energy has far too small a wavelength to match onto the lattice array of energy-source locations. Thus, one concludes that when the nucleus is wavelike and partitioned, all fast energy transfer processes involving energetic particles or gamma rays are blocked.

The blocking of normal fast high energy transfer processes allows a slower process to occur. This slower process allows a stepwise release of the nuclear reaction energy. At the slower rate, energy is transferred to the metal as a result of a weak nuclear-electrical coupling that changes the electric field seen by the conduction electrons of the hosting metal. When deuterons form standing waves, they are neutralized by an equal number of wavelike electrons that also form standing waves over the same volume. This neutralization of the collection of wavelike deuterons by an equal number collection of wavelike electrons limited to the same volume replaces the neutralization of single deuterons by single electrons, which is what occurs with atoms. When a fusion event occurs, 2 wavelike deuterons become one wavelike helium nucleus, while the other wavelike deuterons with their set of neutralizing electrons are not excited. The wavelike deuterons and helium product with their neutralizing electrons continue to keep the lattice electrically neutral. However, there is a sudden change in charge distribution within the superfluid volume. This change occurs instantaneously when wavelike helium is formed. This instantaneous change in charge distribution shocks the much more numerous metal conduction electrons. These conduction electrons are present not only in the volume occupied by the superfluid, but also over a much larger coherent volume. The conduction electrons are part of a coupled "wavelike electron sea" that extends throughout the whole volume of the metal. Only one single electron of these many conduction electrons needs to be scattered to make the nuclear reaction irreversible. A first scattering event absorbs a small amount of energy. This transfer of energy from the wavelike nucleus leaves the nuclear product in a mixed, non-stationary 2D-4He state. This mixed state becomes stable only after a series of fluctuations between deuteron and helium configurations has transferred all the reaction energy to the metal electrons. This relatively slow mechanism explains Process B. It seems to be what happens in normal cold fusion. Note that since the conduction electrons are coherent over a large volume, the energy release is diluted and the local temperature rise associated with single fusion events is relatively small.

It is fortunate that nature not only provides metal crystals with a sequence of potential wells capable of holding hydrogen atoms, but that many metals provide 2 sets of such sequences. In palladium, for example, there is a sequence of deep potential wells (octahedral sites) that can collect individual whole hydrogen atoms, and there is a sequence of shallow potential wells (tetrahedral sites) that meet the requirement for holding a collection of partitioned superfluid hydrogen atoms. The experimenter's problem is that of getting some of the hydrogen atoms to spread out in the sequence of shallow potential wells. There seems to be more than one way of achieving this objective. One way seems to involve forcing a flow of hydrogen over a thin diffusion barrier. The process apparently makes some of the hydrogen nuclei become wavelike. These hydrogen nuclei then spread out over a large volume. This spreading seems to be what occurs in the Iwamura transmutation experiments.

The Iwamura protocol seems to produce partitioned deuterons. It may be that these wavelike deuterons can be directly absorbed by a Cs nucleus, but they have magnetic moments which could inhibit absorption. An alternative is that the deuterons may first fuse to form partitioned helium nuclei, or maybe fused pairs of partitioned helium nuclei. Helium nuclei are the same as alpha particles and have zero magnetic moment and high stability. When helium nuclei form first, there are no configuration barriers to their absorption into a nucleus. The partitioned helium nuclei can then be absorbed exothermically by non-partitioned Cs atoms which are positioned on the lattice surface so as to obstruct the helium waves.

Consider other methods for providing superfluid wavelike deuterium. Whereas Iwamura produces his superfluid wavelike deuteron state by forced deuteron diffusion over a barrier, most other groups have used overvoltage Pd/D2O electrolysis, and have had to achieve a high D/Pd ratio before being able to observe excess heat. Heat production rates are generally observed to increase with temperature, suggesting that thermal excitation physics plays a role in maintaining the nuclear active condition. Superfluid partitioned hydrogen can theoretically exist as a 2-dimensional array on a metal surface or interface, or as a 3-dimensional array within a metal interior. There could be many roads towards practical production of heat, but which road is best remains unclear.

cffuture1 home page: LENR Cold Fusion Process

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The LENR Cold Fusion Process

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