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OBSERVATION OF COLD NUCLEAR FUSION IN CONDENSED MATTER

S. E. Jones, E. P. Palmer, J. B. Czirr, D. L. Decker, G. L. Jensen, J. M. Thorne, and S. F. Taylor

Department of Physics and Chemistry Brigham Young University Provo, Utah 84602

and

J. Rafelski Department of Physics University of Arizona Tucson, Arizona 85721 March 23, 1989

Fusion of isotopic hydrogen nuclei is the principal means of producing energy in the high-temperature interior of stars. In relatively cold terrestrial conditions, the nuclei are clothed with electrons and approach one another no closer than allowed by the molecular Coulomb barrier. The rate of nuclear fusion in molecular hydrogen is then governed by the quantum-mechanical tunneling through that barrier, or equivalently, the probability of finding the two nuclei at zero separation. In a deuterium molecule, where the equilibrium separation between deuterons (d) is 0.74 A, the d-d fusion rate is exceedingly slow, about 10E-70 per D molecule per second. [1] 2

By replacing the electron in a hydrogen molecular ion with a more massive charged particle, the fusion rate is greatly increased. In muon-catalyzed fusion, the internuclear separation is reduced by a factor of approximately 200 (the muon to electron mass ratio), and the nuclear fusion rate correspondingly increases by roughly eighty orders of magnitude [1]. Muon-catalyzed fusion has been demonstrated to be an effective means of rapidly inducing fusion reactions in low- temperature hydrogen isotopic mixtures [2].

A hypothetical quasi-particle a few times as massive as the electron would increase the cold fusion rate to readily measurable levels, about 10E-20 fusions per d-d molecule per second [1]. Our results imply that an equivalent distortion on the internuclear hydrogen wavefunction can be realized under certain conditions when hydrogen isotopic nuclei are loaded into metallic crystalline lattices and other forms of condensed matter.

We have discovered a means of inducing nuclear fusion without the use of either high temperatures or radioactive muons. We will present direct experimental results as well as indirect geological evidence for the occurrence of cold nuclear fusion.

DETECTION OF COLD FUSION NEUTRONS

We have observed deuteron-deuteron fusion at room temperature during low-voltage electrolytic infusion of deuterons into metallic titanium or palladium electrodes. The fusion reaction

3 d + d -> He (0.82 MeV) + n (2.45 MeV) (1a)

+ is evidently catalyzed as d and metal ions from the electrolyte are deposited at (and into) the negative electrode. Neutrons having approximately 2.5 MeV energy are clearly detected with a sensitive neutron spectrometer. The experimental layout is portrayed in Figure 1. We have not yet obtained results regarding the parallel reaction

d + d -> p (3.02 MeV) + t (1.01 MeV) (1b)

as this requires different measuring procedures. However, it can be presumed that the reaction (1b) occurs at a nearly equal rate as the reaction (1a), which is usually the case.

The neutron spectrometer, developed at Brigham Young University over the past few years [3], has been crucial to the identification of this cold fusion process. The detector consists of a liquid organic scintillator (BC-505) contained in a glass cylinder 12.5 cm in diameter, in which three lithium-6-doped glass scintillator plates are embedded. Neutrons deposit energy in the liquid scintillator via collisions and the resulting light output yields energy information. These, now low-energy neutrons are then scavenged by lithium-6 nuclei 6 4 in the glass plates where the reaction n + Li --> t + He results in scintillations in the glass. Pulse shapes from the two media differ so that distinct signals are registered by the two photomultiplier tubes (whose signals are summed). A coincidence of signals from the two media with 20 microseconds identifies the neutrons.

An energy calibration of the spectrometer was obtained using 2.9 and 3.2 MeV neutrons, generated via deuteron-deuteron interactions at 90 degrees and 0 degrees, respectively, with respect to the deuteron beam from a Van de Graaf accelerator. The observed energy spectra show a broad structure which implies that 2.45 MeV neutrons should appear in the multi-channel analyzer spectrum in channels 45-150. Stability of the detector system was checked between data runs by measuring the counting rate for fission neutrons from a broad-spectrum californium- 252 source. We have performed other extensive tests proving that our neutron counter does not respond in this pulse height range to other sources of radiation such as thermal neutrons.

Background rates in the neutron counter are approximately 10E-3 1/s in the energy region where 2.5 MeV neutrons are anticipated. By comparing energy spectra from gamma and neutron sources we have determined that nearly all of the background stems from accidental coincidences of gamma-ray events. Improvements in the shielding and gamma-ray rejection were pursued throughout the experiments, resulting in significant reduction in background levels.

During the search for suitable catalytic materials, we developed the following (unoptimized) prescription for the electrolytic cells. The electrolyte is a mixture of 160 g deuterium oxide (D O) plus various 2

metal salts in 0.2 g amounts each: FeSO . 7H O, NiCl . 6H O, 4 2 2 2

PdCl , CaCO , Li SO . H O, NaSO . 10H O, CaH (PO ) . H O, 2 3 2 4 2 4 2 4 4 2 2

TiOSO . H SO . 8H O, and a very small amount of AuCN. 4 2 4 2

(Our evidence indicates the importance of co-deposition of deuterons and metal ions at the negative electrode.) The pH is adjusted to pH < 3 with HNO . Titanium and palladium, initially selected because 3 of their large capacities for holding hydrogen and forming hydrides, were found to be effective negative electrodes.

Other metals receiving preliminary tests include lanthanum, nickel, iron, copper, zirconium, tantalum, and lithium-aluminum hydride. Individual electrodes consisted of approximately 3 g purified "fused" titanium in pellet form, or 0.5 g of 0.25 mm thick palladium foils, or 5 g of mossy palladium. Typically 4-8 cells were used simultaneously. The palladium pieces were sometimes reused after cleaning and roughening the surfaces with dilute acid or abrasives. Hydrogen bubbles were observed to form on the Pd foils only after several minutes of electrolysis, suggesting the rapid absorption of deuterons into the foil; oxygen bubbles formed at the anode immediately. Gold foil was used for the positive electrodes. DC power supplies provided 3-25 volts across each cell at currents of 10-500 mA. Correlations between fusion yield and voltage, current density, or surface characteristics of the metallic cathode have not yet been established.

Small jars, approximately 4 cm high x 4 cm diameter, held 20 ml of electrolyte solution each. The electrolytic cells were placed on or alongside the neutron counter, as shown in Figure 1. The cells are simple and doubtless far from optimum at present. Nevertheless, the present combination of our cells with the state-of-the-art neutron spectrometer is sufficient to establish the phenomenon of cold nuclear fusion during the electrolytic infusion of isotopic hydrogen into metals.

Figure 2 displays the energy spectrum obtained under conditions described above, juxtaposed with the background spectrum. Assuming conservatively that all deviations from background are statistical fluctuations, we scale the background counts by a factor of 0.46 to match the foreground counts over the entire energy range (Figure 2). A feature in channels 45-150 still rises above background by nearly four standard deviations. This implies that our assumption is too conservative and that this structure represents a real physical effect. By re-scaling the background by a factor of 0.44 to match the foreground level in regions outside this feature, the difference plot (Figure 3) is obtained. It shows a robust signal centered at channel 100 of over five standard-deviation statistical significance. A Gaussian fit to this peak yields a centroid at channel 101 and a sigma of 28 channels. This is precisely where 2.5 MeV fusion neutrons should appear in the spectrum according to our calibration. The fact that a significant signal appears above background with the correct energy for d-d fusion neutrons ( 2.5 MeV) provides strong evidence that room temperature nuclear fusion is indeed occurring in our electrolytic catalysis cells.

FUSION RATE DETERMINATION

It is instructive to scrutinize the fourteen individual runs which enter into the combined data discussed above. Figure 4 displays, for each run, the ratio of foreground count rate in the 2.5 MeV-energy region with background rates obtained for each run. Background rates were improved upon during the experiments, so we plot the data in terms of foreground-to-background ratios rather than absolute rates.

Run 6 is particular noteworthy, having a statistical significance of approximately 5 standard deviations above background. Fused titanium pellets were used as negative electrodes with a total mass of about 3 g. The neutron production rate increased after about one hour of electrolysis. After about eight hours, the rate dropped dramatically as shown in the follow-on run 7. At this time, surfaces of the Ti electrodes showed a dark gray coating. An analysis using electron microscopy with a microprobe showed that the surface coating was mostly iron, deposited with deuterons at the cathode. The same phenomenon of having the neutron signal drop after about eight hours of operation appears in run 13 followed by run 14. Runs 13 and 14 used the same eight electrochemical cells, and again the negative electrodes developed coatings after a few hours of electrolysis. These observations suggest the importance of surface conditions on the cold fusion process. Indeed, wide variations in surface conditions are anticipated in the operating electrochemical cells with numerous ionic species, and these variations may account for the fluctuations in the signal level which are evident in Figure 4. In particular, the observed "turning off" of the signal after 8 hours may account for a low signal-to-background ratio in runs 1 and 3, in that a few-hour signal may have been overwhelmed after a long (20 hour) running time.

When run 10 started with rates substantially above background, we stopped the run and removed half of the electrochemical cells as a test. The neutron production rate dropped off as expected (run 11). In determining the statistical significance of the data, we included runs 1, 3, 7, 11 and 13, even though we see a systematic reason for their low foreground-to-background ratios as explained above. Run 8, shown in Figure 4, was inadvertently lost from the magnetic storage device and could not be included in Figures 2 and 3. This does not change our conclusions.

Extensive efforts were made to generate fake neutron signals by using various gamma and neutron sources. We also turned auxiliary equipment on and off; the Van de Graaf accelerators were kept off. The signals persisted as shielding was moved and as electronics modules were tuned and even replaced. Background runs taken using operating electrochemical cells similar to those described above but with H O replacing the D O were featureless. No net counts above 2 2 background when standard cells were used with no current flowing.

The cold nuclear fusion rate during electrolytic fusion is estimated specifically for run 6 (Figure 4) as follows:

[ R ] / [ d ] Fusions per deuteron pair = [ --- ] / [ M x --- ] (2) [ e ] / [ 2M ]

where the observed fusion rate R = (4.1 +- 0.8) x 10E-3 fusions/s; the neutron detection efficiency, including geometrical acceptance, is calculated using a monte carlo neutron-photon transport code [4] to be e = (1.0 +- 0.3)%; M = 4x10E22 titanium atoms for 3 g of titanium; and the deuteron-pair per metal ion ration d/(2M) = 1 is based on the assumption that nearly all tetrahedral sites in the titanium lattice are occupied, forming the gamma-TiD hydride. Then 2 the estimated cold nuclear fusion rate by equation (2) is

lambda 10E-23 fusions/deuteron pair/second (3) f

If most fusions take place near the surface or if the titanium lattice is far from saturated with deuterons, or if conditions favoring fusion occur intermittently, then the inferred fusion rate must be much larger, perhaps 10E-20 fusions/d-d/second.

We note that such a fusion rate could be achieved by "squeezing" the deuterons to half their normal (0.74 A) separation in molecules. That such rates are now observed in condensed matter suggests "piezonuclear" fusion as the explanation [1]. A possible cause is that quasi-electrons form in the deuterated metal lattice having an effective mass a few times that of a free electron. Isotopic hydrogen is known to accumulate at imperfections in metal lattices [5] and local high concentrations of hydrogen ions might be conducive to piezonuclear fusion. Since we have not seen any evidence for fusion in equilibrated, deuterated metals or compounds such and methylamine-d dueteriochloride or ammonium-d chloride, we conclude 2 4 that non-equilibrium conditions are essential. Electrolysis is one way to produce conditions which are far from equilibrium.

It seems remarkable that one can influence the effective rate of fusion by varying external parameters such as pressure, heat and electromagnetic fields, but just such effects are confirmed in another form of cold nuclear fusion; muon-catalyzed fusion [6]. Such variations are naturally encountered in the geological environment where heat, pressure, and contact potentials will generate severely non-equilibrium conditions.

GEOPHYSICAL CONSIDERATIONS

The observation of evidence for cold d-d fusion in the laboratory has profound geophysical implications. Thermal effects in the earth and 3 the distribution of He and tritium can be explained in part by the fusion reactions (1) and

3 p + d -> He + gamma (5.4 MeV) (4)

Deuterium was incorporated in the earth during its formation. The current abundance in sea water is about 1.5x10E-4 deuterons per proton. Water is carried down into the earth's upper mantle at converging plate margins, and seawater is transported as deep as the Moho at spreading regions [7]. Estimates of water subduction suggest that a water mass equal to the ocean mass is cycled through the mantle in about 1-billion years [7]. Thus, 1.4x10E43 deuterons are cycled through the mantle in 3x10E16 s. Since each p-d fusion releases 5.4 MeV (8.6x10-13 J), we calculate that a heat flux of 750 mW/(m*m), averaged over the earth, would result if all deuterium fused at the rate at which it is supplied by subduction. This is more than ten times the estimate of the actual flux of 60 mW/(m*m) [8]. Thus, geological p-d fusion could possibly contribute to the observed heat flux, the high temperatures of the earth's core and provide an energy source for plate tectonics.

The foregoing data allow a geological fusion rate lambda to be f calculated. We assume a first-order rate equation for p-d fusion: dN = lambda N dt, or lambda = (dN/N)dt. The fraction (dN/N) f f is the ratio of the number of fusions which take place to the number of atoms available. It is also the rate of fusion divided by the rate of supply of deuterons; thus, dN/N is equal to the actual heat flux from the earth divided by the possible heat flux so that

-1 lambda = (60/750)/3x10E16 s = 3x10E-18 s (5) f

Consider next the possibility that the localized heat of volcanism at subduction zones is supplied by fusion. As much as 10E6 J/kg is required to turn rock into magma, and this must be supplied from a local source of energy. Subducting rock contains about 3 percent water [7], or 3x10E30 deuterons/kg. If the time available for melting is equal to the time required for a plate to travel down a slant distance of 700 km at a speed of 2.5 cm/year, about 10E15 s, the inferred fusion rate is:

lambda = (10E6 J/kg)/(3x10E20 d/kg x 8.6E10-13 J/fusion x 10E15 s) f lambda = 4x10E-18 fusions/d/s (6) f

This requires only about 0.3 percent of the available nuclear fuel. The limit on the available heat is therefore the fusion rate constant, rather than the scarcity of fuel.

While some of the earth's heat must certainly derive from several sources, "cold" geological nuclear fusion could account for steady- 3 state production of considerable heat and He in the earth's interior. 3 4 High values of the He/ He ratio are found in the rocks, liquids, and gases from volcanoes and other active tectonic regions [9]. 3 Primordial He will be present from the formation of the earth [9], but some may be generated by terrestrial nuclear fusion. The discovery of cold nuclear fusion in the laboratory, with a rate constant comparable to that derived from geologic thermal data, supports our hypothesis.

Based on this new concept, we predict that some tritium should be produced by d-d fusion in the earth (see equation 1). Since tritium 3 decays according to t -> He + beta with a 12-year half-life, detection of tritium in volcanic emissions would imply cold-fusion production of tritium. This is supported by the following observations. A tritium monitoring station was operated at Mauna Loa on Hawaii Island from August 1971 to the end of 1977. We have found strong correlations between tritium detected at Mauna Loa and nearby volcanic activity in this period of time. Figure 4 displays data compiled by Ostlund for HT gas measured at the Mauna Loa station in 1972 [10]. Similar data taken at Miami, Florida, are provided for comparison. A striking spike in the tritium level is clearly seen in the February-March 1972 Mauna Loa data. Ostlund notes that these significant tritium readings over a several-week period have not been previously understood; in particular, the timing and shape of the peak is inconsistent with hydrogen bomb tests in Russia five months earlier [10]. However, this signal is coincident with a major eruption of the Mauna Ulu volcano [11] 40 km to the southeast. Furthermore, winds in March 1972 carried volcanic gases northwest, towards the Mauna Loa station and on towards Honolulu 200 km away: "Trade winds [from the northeast] were infrequent and the southerly flow that replaced them occasionally blanketed the state with volcanic haze from an eruption on Hawaii Island ... High particulate matter measurements in Honolulu confirmed the northward spread of haze from the Mauna Ulu Volcano eruption on Hawaii Island." [12]

This remarkable set of circumstances permits us to estimate the amount of tritium released during the February-March 1972 eruption of Mauna Ulu. Based on the distance to the Mauna Loa station and average 8 mph winds [12], we estimate that on average 100 curies of tritium were released per day for 30 days. An accidental release of this magnitude of manmade tritium sustained for several weeks on a nearly uninhabited island is highly unlikely. We conclude that this volcanic eruption freed tritium produced by geological nuclear reactions.

Other HT data from the Mauna Loa station, such as the high reading in the latter half of 1972, are also coincident with volcanic activity, although a tritium-releasing bomb test also occurred in Russia in late August. A major spike in the atmospheric HT observed near Hawaii in Dec 1974 - June 1975 [10] coincides with another large volcanic eruption on Hawaii Island, but the significance is again obscured by H-bomb tests. Finally, no significant deviations in HT reading are noted in 1976 or 1977 [10] when no volcanic activity is noted, except for "gentle" activity at Kileau on September 17, 1977 [13].

OTHER EVIDENCES FOR COLD FUSION

Further evidence for cold nuclear fusion in condensed matter comes 3 4 from studies of He and He in diamonds and metals. Using laser- slicing of diamonds, H. Craig (private communication) has measured the 4 3 4 absolute concentrations of both He and He. He was found to be smoothly distributed through the crystal as if it were derived from 3 the environment. On the other hand, He was found to be concentrated in spots implying in-situ formation. Cold piezonuclear p-d or d-d fusion provides a plausible explanation for these data.

3 Concentration anomalies of He have also been reported in metal foils 3 [14]. The spotty concentrations of He suggest cold piezonuclear 3 fusion as the origin of the observed He. Note that electrolytic refining of the metals in deuterium-bearing water could have provided conditions for cold nuclear fusion. Among several possible explanations, the authors [14] suggest an "analog" of muon catalysis. We think they were close to the mark!

Cold nuclear fusion may be important in other celestial bodies besides earth. Jupiter, for example, radiates about twice as much heat as it receives from the sun [1]. It is interesting to consider whether cold nuclear fusion in the core of Jupiter, which is probably metallic hydrogen plus iron silicate, could account for its excess heat. Heat is radiated at an approximate rate of 10E18 W, which could be produced by p-d fusions occurring at a rate of 10E20(1/s) [1]. Assuming a predominately hydrogen core of radius 4.6x10E9 cm, having a density = 10 g/(cm*cm*cm) and a deuteron/proton ratio of roughly 10E-4, we deduce a required p-d fusion rate of lambda = 10E-19 f fusions/deuteron/second--in remarkable agreement with cold fusion rates found in terrestrial conditions.

CONCLUSIONS

A new form of cold nuclear fusion has been observed during electrolytic infusion of deuterons into metals. While the need for off-equilibrium conditions is clearly implied by our data, techniques other than electrochemical may also be successful. We have begun to explore the use of ion implantation, and of elevated pressures and temperatures mimicking geological conditions.

If deuteron-deuteron fusion can be catalyzed, then the d-t fusion reaction is probably favored due to its much larger nuclear cross section. Thus, while the fusion rates observed so far are small, the discovery of cold nuclear fusion in condensed matter opens the possibility at least of a new path to fusion energy.

We acknowledge valuable contributions of Douglas Bennion, David Mince, Lawrence Rees, Howard Vanfleet and J. C. Wang of Brigham Young University, and of Mike Danos, Fraser Goff, Berndt Muller, Albert Nier, Gote Ostlund, and Clinton Van Siclen. We especially thank Alan Anderson for advice on the data analysis and Harmon Craig for continuing encouragement and for use of his data on diamonds before their publication.

The research is supported by the Advanced Energy Projects Division of the U.S. Department of Energy.

REFERENCES

1. Van Siclen, C. D. & Jones, S. E. "Journal of Physics G. Nucl. Phys." 12, 213-221 (1986).

2. Jones, S. E. "Nature" 321, 127-133 (1986); Rafelski, J. & Jones, S. E. "Scientific American" 257, 84-89 (July 1987).

3. Jensen, G. L., Dixon, D. R., Bruening, K. & Czirr, J. B. "Nucl. Inst. and Methods" 200, 406 (1984); and paper in preparation.

4. MCNP: Monte Carlo Neutron and Photon Transport Code, CCC-200. Available from Radiation Shielding Information Center, Oak Ridge National Laboratory (Version 3).

5. Bowman, R. C. Jr. in "Metal Hydrides" (ed. G. Bambakides) 109-144 (New York, Plenum, 1981).

6. Jones, S. E., et al. "Physical Review Letters" 51, 1757-1760 (1983).

7. Fyfe, W. S., Price, N. J., & Thompson, A. B. "Fluids in the Earth's Crust" (Elsevier, New York, 1978).

8. Chapman, D. S. & Pollack, H. N. "Earth and Planet Sci. Lett" 28, 23 (1975)

9. Craig, H., Lupton, J. E., Welhan, J. A., & Proveda, R. "Geophys. Res. Lett." 5, 897 (1978); Lupton, J. E., & Craig, H. "Science" 214, 13 (1981); Mamyrin, B. A. & Tolstikhin, L. N., "Helium Isotopes in Nature (Elsevier, Amsterdam, 1984).

10. Ostlund, H. G. & Mason, A. S. Atmospheric Tritium 1968-1984, Tritium Laboratory Report No. 14, University of Miami, Miami, Florida; Ostlund, H. G., private communication.

11. Bullard, F. M. "Volcanoes of the Earth", 2nd ed., (Univ. Texas Press, Austin, 1984).

12. U.S. Dept. of Commerce, "Climatological Data, Hawaii" 68, 29 (1972).

13. Smithsonian Institution, "Volcanoes of the World", (Stroudsburg, P. A., Hutchinson Ross Publishing Co., 1981).

14. Mamyrin, B. A., Khabarin L. V. & Yudenich, V. S. "Sov. Phys. Dokl." 23, 581 (1978).