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147) EXTRACTS FROM A GOOD OLD PAPER
Ludwik Kowalski (6/8/04)
Department of Mathematical Sciences
Montclair State University, Upper Montclair, NJ, 07043
Four years ago Edmund Storms published a long review paper entitled “A Critical Evaluation of the Pons-Fleischmann Effect.” It appeared in two parts (1); the paper is also available over the Internet (2). In the abstract of the paper the author wrote: “Many new studies are available to make an objective evaluation of the Pons-Fleischmann effect possible. The phenomenon is conventionally known as “cold fusion,” or “chemically assisted nuclear reactions (CANR)” when the environment is emphasized, or “low-energy nuclear-reactions (LENR)” if emphasis is placed on the process. A wide range of observations involving anomalous production of energy as well as nuclear products have been published. While many of the claims are still open to interpretation, the general conclusion is that an important, novel phenomenon has been discovered which deserves renewed interest.” Below are arbitrarily selected extracts from this paper. Many findings described at the 10th anniversary of the announced discovery of cold fusion have been confirmed in subsequent five years. That is what, I suppose, prompted the pending DOE evaluation of cold fusion. Storms was probably an important promoter of this initiative.
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1) Ten years of work worldwide have produced over 2500 published papers[5], many peer reviewed, which have answered most of the objections leveled by critics. It is now possible to make a more objective evaluation of the phenomenon than was previously possible. Unfortunately, during this time the claims have been the subject of considerable distortion. The reader is asked to lay aside the emotional reaction “cold fusion” can generate and read the following arguments with an open mind. Some readers will be put off by the clear conflict between claimed behavior and well accepted theory of nuclear interaction presently in vogue. The author is well aware of this problem. Nevertheless, a large collection of anomalous behavior must be explained. The fact that this behavior cannot be explained by conventional theory should only serve to challenge theoreticians rather than be used as justification for rejection. . . . The field which is conventionally called “Cold Fusion” has grown and now should be called “Chemically-Assisted Nuclear Reactions” or “Low-Energy Nuclear Reactions,” depending on the emphasis one wishes to apply. The claims are supported by a wide range of anomalous behaviors involving nuclear reactions and energy production.
2) Numerous critics have observed that “extraordinary claims require extraordinary proof.” This is a very high standard which has prematurely doomed many new ideas to the trash bin, some deserving and some not. We need to realize that potential errors can be found by clever critics in any study, no matter how well done. Hence, a perfect proof is almost impossible to obtain until considerable information has accumulated. Such an accumulation is very slow and difficult if an idea is completely rejected, as has been done in this case. Consequently, at the very least, I would hope that the skeptical reader would entertain the possibility that some part of the claims deserve further study, even though all important questions have not, as yet, been answered.
3) If the process does not involve conventional fusion, what is producing the anomalous energy? Critics attribute the extra energy to error in measurement or normal, overlooked chemical processes. This assertion will be addressed in the following section. Four questions must be answered when evaluating this experimental work: (a) Was the calorimetric technique used by Pons and Fleischmann sufficiently stable and accurate to see the claimed extra energy? (b) Can prosaic sources of chemical energy be ruled out? (c) Have other people replicated the claims using sufficiently stable and accurate calorimeters? (d) Have reasons for success or failure been discovered?
4) Before answering the first question, a general comment about the calorimetric method is necessary. Critics have misunderstood the difference between relative and absolute calorimetry in their search for errors.[12] Although the absolute approach was used during early measurements in order to detect an immediate production of energy, this method was later found to be unnecessary, because production of energy was found to require a long wait. This delay allows a null condition to be defined, independent of absolute knowledge of power production. Any random variation in the signal is also revealed during this interval. In addition, repeated calibration during this delay can be used to demonstrate that the calorimeter is stable. Consequently, referencing the data to an initial zero value, as is done in most publications, is convenient but not necessary.
Instead, power production is claimed when the signal rises above a previously steady but arbitrary background value. Seeing a signal rise out of the noise is easy and does not depend in any way on knowing the actual amount of heat being produced in the cell. The magnitude of the resulting energy is then calculated using the change in cell conditions and the calibration constant. All absolute values of error in temperature, voltage, current, and other conditions cancel, provided the values for these quantities have remained constant. As a result, the observed presence of excess energy is more certain than is its absolute value. If an error is to be found, it must explain how a sudden change can occur in previously stable conditions and how this change can be missed by repeated calibrations and studies of inert materials, so-called control experiments. Nevertheless, some overlooked errors are important and will be discussed.
5) Electrolytic action decomposes heavy water to give D2 and O2, which carry away chemical energy upon leaving the cell. Should some fraction of these gases unexpectedly react to reform water within the cell, the actual amount of energy being generated in the calorimeter would be uncertain. Kreysa et al.[13] immediately raised this issue because P-F did not address the problem in their original paper. Later P-F [14] stated that the amount of recombination was determined by measuring the amount of water which disappeared from the cell as a function of time and applied current, and that the amount was insignificant.
6) Overlooked by these studies is another possible source of error. Knowledge of the amount of energy being produced in such a calorimeter requires the thermal conductivity of the wall be known and stable. Stirring changes the effective thermal conductivity of the wall because the amount of stagnate fluid next to the wall is changed. This factor is very sensitive to the amount of fluid convection next to the wall and shows no saturation as convection is increased.[25] This effect can be seen in Figure 3 which shows the relationship between effective thermal conductivity of the cell wall as a function of stirring rate. Even mechanically stirred devices will suffer an error if the stirring rate should change. Whether this effect is important depends on the frequency of calibration, the type of calibration used, and the constancy of bubble action. Therefore, the effect of this error on the various studies using the isoperibolic method is hard to judge. To the extent that it operates, one should see an apparent positive as well as negative anomalous energy. All reported data show only positive excursions.
7) Three studies have evaluated the basic design of the P-F calorimeter. The first was commissioned by General Electric Co. and reported by Wilson et al. [26]. The two most serious problems they note are the change in calibration constant produced by liquid level change, and potential loss of heavy water with the evolving gases, thereby producing a loss of overlooked energy. The authors acknowledged that P-F avoided the effect of these errors, as well as several others, by frequent calibration. Thus, changes in cell conditions could be quickly eliminated as being the cause of anomalous energy. Although the authors claimed to find some minor mistakes, the final conclusion of this analysis is that only the magnitude of the anomalous energy can be questioned by their analysis, not its existence. Because their attempts to duplicate the claimed energy production using various types of palladium, cell designs, electrolytes, and anode metals were unsuccessful, they were not optimistic about the reality of the claims.
8) Before going on to examine attempts at replication, it is worth first discussing the P-F measurements in detail because they were the focus of so much criticism. Figure 4 shows a drawing of the P-F cell. In this case, electrolytic action occurs in a cell which is surrounded by a vacuum jacket that is silvered except near the top. Thus, the thermal barrier is located at the top of the cell, including the lid. This assembly is placed in a constant-temperature water bath. Contained in the cell along with the anode (Pt) and cathode (Pd) are a glass-covered heater, a single glass covered thermistor, and a reference electrode. P-F answered some of the criticisms in several papers[30; 31; 32] from which the following observations can be summarized: Currents between 25 mA and 804 mA were used with most measurements taken above 100 mA. Thus, most measurements were outside of the critical current range for internal recombination- . Furthermore, they state that the amount of recombination was measured by monitoring the amount of D2O used. Recombination was found to be no greater than 1% of applied power. Mixing was found to be adequate to eliminate temperature gradients based on experimental observation as noted above. with the resulting temperature rise and decay noted. This type of calibration allowed pulsed as
well as sustained heat production to be evaluated.
9) The hard-to-accept claim for a nuclear source is based, in part, on the belief that observed energy production exceeds any known chemical source. Therefore, the potential chemical sources must be examined. Before discussing this subject in detail, the reader should realize that a typical cell contains very few chemical components, all of which are stable with respect to each other. A chemical reaction can only be initiated by applying an electric current, a process which uses energy. Only after the water has been split into deuterium and oxygen can chemical reactions occur. This process causes several chemical reactions, including an uptake of deuterium by the palladium and slow deposition of lithium and platinum on the cathode surface.
Each of these reactions involve very little energy. Strain energy accumulates in the palladium and small amounts of reaction products such as D2O2 can accumulate in the solution under proper conditions. These processes have the potential to store energy within the cell. Only release of stored energy can be used to explain the anomalous energy, which appears after many hours of electrolysis. The magnitude of such processes was addressed in several papers. Kainthla et al.[37] discussed eight possible sources, including recombination, which has been already discussed above. The other sources are the energetics of PdD formation, the energetics of PdLi formation, and energy accumulation as stress. Each of these was found to be much too small to account for even the smallest reported excess energy. Handel[ 13].
10) These [calorimetric setups] share the following features: [44]; (a) The cells are sealed and contain a recombiner. As a result, no gas leaves the cell. Therefore, uncertainty in the amount of recombination is not an issue. Successful action by the recombiner is monitored using different methods including the change in gas pressure. (b) The cells contain a heater which maintains a constant inner temperature. Power to this heater is adjusted to compensate for any change in power production within the cell produced by electrolysis or by anomalous processes. This heater is also used to determine whether the power measurement, based on the flow rate and temperature change of the cooling fluid, is accurate. A sensitivity of better than ±0.01 W (±0.1%) is claimed. (c) The electrolytic cell, its surrounding heater, and the cooling-fluid channels are all contained within a silvered, evacuated dewar in order to isolate them from the environment. (d) The whole assembly is immersed in a fluid bath which maintains a constant environment of 30±0.003°C. This bath is also the source of cooling fluid. Consequently, most studies are done at a constant temperature of 30°C. (e) A constant flow pump is used to circulate cooling fluid. Flow rate is checked periodically by weighing the fluid. Better than 98% of power produced within the cell is captured in this fluid. (f) All aspects of the measurement are under computer control, which provides continuous monitoring, and redundant RTDs are used for temperature measurement. (g) The deuterium content of the palladium cathode is determined by measuring its change in resistance. (h) Most studies involve a similar calorimeter containing an inert cathode as a reference. Both calorimeters are run electrically in series and measurements alternate between the two systems using the same voltage and current meters.
Flow calorimetry is relatively simple and suffers from fewer errors compared to the isoperibolic method used by other people, as well as by P-F. Only four physical measurements are required. The applied power is determined by measuring applied voltage and current at the isothermal boundary, and the released power is obtained by measuring the flow rate and the temperature change of the cooling fluid. Internal temperature gradients are not important, stirring is not an issue, and uncertain recombination is not a source of potential error. Only unexpected changes in the measuring systems can introduce error. McKubre et al. have demonstrated their instruments to be stable and accurate through years of use. On the other hand, an evaluation of this study can assume prosaic errors which might have been overlooked in spite of this experience, as several skeptics have attempted to do. Two possibilities will be examined. . . .
11) Figure 5 compares many studies, some of which show a clear relationship between applied current density and heat production. In addition, an example obtained by McKubre et al. is shown in Figure 10. Similar studies by Storms [50] and by Hasegewa et al.[48] are shown in figures 9 and 11, respectively. Indeed, even P-F mentioned this behavior but their advice was largely ignored by those who suffered failure.
What prosaic process could cause the apparent excess energy to rise as applied current is increased? Increased current has three major effects. It increases the AC component being measured in the DC current and voltage, increases the number of bubbles, increases the amount of energy being dissipated by the cell, and increases the chemical activity of deuterium at the cathode surface. The effect of an error in the measured current and voltage has been discussed above. Increased bubble production will cause increased mixing. For those studies using an isoperibolic calorimeter, this can only have a minor effect as explained above. Flow-type calorimeters would not be affected at all. Increased production of heat could have an effect if the calibration constant were not constant, but changed as the electrolyte temperature changed. Failure to recognize this nonlinear behavior could produce an error at temperature or current extremes. The author has seen this behavior after the current was applied to an isoperibolic calorimeter for a long time. Apparently, the path for heat loss can change, thereby changing the behavior of the calibration constant. Figure 8. Effect of average bulk composition on production of excess power using palladium wire. However, the effect is small, causing less than a 0.5 W error. Repeated calibrations, as is done in many studies, would reveal the problem. This effect would not apply to a flow-type calorimeter such as used by McKubre et al. because such calorimeters are largely immune to where heat is being produced within the cell.
12) The effect occurs in only a small fraction of samples but more often in certain batches than in others. Only a few organizations have the funding to allow many samples to be investigated for heat production. SRI [51] studied 176 samples with 19 giving excess energy. However, many of these studies were for the purpose of learning how high loading could be obtained rather than Figure 11. Effect of applied current on excess power shown by Hasegewa et al.[48] seeking excess energy. The successful samples correlated to a high degree with the average composition and many came from the same batch. Takahashi [52] reports studying twenty plates, only three of which gave excess energy in the 3-5 watt level. Both Storms[53] and Kobayashi et al.[54] were able to replicate excess energy production using material from the same batch of palladium which produced excess power for Takahashi. Ota et al. [55] studied 79 samples over a nine year period and found fourteen to give less than 0.25 W, 5 to give power between 0.25 W and 0.50 W and only three to produce greater than 0.50 W. The rest showed no sign of excess energy. Storms studied fourteen plates and found only six that produced excess power in the 1.1-4.5 watt range. The effect correlated with the amount of cracking experienced by the samples and the average composition. Miles et al.[56] found that 20% of their samples gave excess energy with a high fraction coming from a few batches.[57] The results are listed in Table 2. Those samples containing boron or cesium produced
a high success rate, while other samples and alloys were frequently dead. It is important to note that all samples supplied to
Miles by P-F produced excess energy. In addition, a sample which was found to produce excess energy at China Lake (U.S.) also produced excess when it was studied at the NHE Laboratory in Japan.[58] Thus, once again, the effect could be duplicated when the same material was used. This effect is attributed to the variable nature of palladium metal, especially because certain batches give a very high success rate. However, the behavior can also be explained by assuming poor stability in the calorimeters used, thus the insistence by critics that blank, control cells be studied. Unfortunately, no one working in this field has had funds to support an extensive study of blank cells, although most workers have studied a few such samples. Such blanks normally use platinum in place of palladium and H2O in place of D2O. When blank cells were studied, no excess energy is reported.[59] Many skeptics discount this claim by not trusting the experimenters to objectively evaluate the results or they attribute the claimed excess power to chance variations in the measuring system.
13) The above requirements provide many avenues for failure. Success, first of all, requires palladium which is able to achieve a critical composition at the surface.[60] The average bulk composition is only important because it is required to support this high surface composition. Unfortunately, most palladium forms cracks when it loads with deuterium so that the deuterium escapes faster than it can be delivered.[50] Only a small fraction of available palladium does not show this behavior. Second, the heavy water must be free of normal water to prevent deuterium in palladium from being diluted by normal hydrogen.[61; 62] Because heavy water quickly picks up normal water from the air, it can easily become diluted and made inactive. Once potentially active palladium has been acquired[63], it must be handled correctly.
This includes making sure the surface is free of finger prints and other contaminants as well as scratches. Annealing must be done in a very good vacuum to prevent formation of even a monolayer of surface impurity. The ease with which palladium can suffer surface contamination is one of the important problems which is frequently overlooked. Crystal size is also thought to be important, a property which is strongly influenced by annealing. Treatment with Aqua Regia is sometimes needed to remove unavoidable surface films. After these pretreatments, the material must be subjected to proper loading conditions. Applying only a small current for the first several days improves the chance of reaching a high composition. Only after the composition has been achieved at stable value should the current be increased into the critical range. Too fast loading or premature application of high current can produce cracking, followed by immediate loss of deuterium.[51; 64] Palladium is much more sensitive to how it is treated than most people realize. These requirements were not known by most early workers in the field, hence success was more a matter of luck than skill. Even now, many attempts to duplicate the claims do not apply these lessons. Unless this experience is applied, a failed effort cannot be claimed as a true duplication.
14) Clearly, anomalous energy is not a product of a conventional fusion reaction, nor does it show the behavior found during “hot fusion.” Nevertheless, anomalous emissions have been detected on numerous occasions, including neutrons, X-rays, g-rays, charged particles, as well as radiation from radioactive products. While such radiation along with production of radioactive and nonradioactive products suggest anomalous nuclear activity, this paper will not attempt to assess these claims. Helium is another possible nuclear product which can be produced by several nuclear reactions besides fusion. This element was looked for and found by numerous investigators in several different environments including in the gas[56; 65; 66; 67; 68; 69; 70], dissolved in the materials[71; 72; 73; 74; 75; 76; 77], and emitted as charged particles[78; 79; 80]. Naturally, not all studies are definitive and some failed to find helium when it was sought. While these observations are suggestive, only two independent measurements have provided a quantitative relationship between anomalous power production and helium production rate.
Both studies used all-metal systems and measured helium in the flowing gas generated during continuous electrolysis. Two different calorimeter types were used and the helium was measured at two different laboratories. These two studies are compared in Figure 12. Three conclusions can be drawn from the figure. First, the two studies agree very well, given the difficulty of the measurement. Second, the He/sec-watt values are largely independent of observed anomalous power, as would be expected if the two quantities are functionally related. Third, the average values are within a factor of 2 of being consistent with an energy of 24 MeV/helium atom, the value expected when 4He is occasionally produced by conventional fusion. . . .
Thus, anomalous helium was found only when anomalous heat was detected. Only one cell, which used a Pd-Ce alloy, showed heat but no helium. This result is strongly against chance alone. When the helium producing branch of the fusion reaction has been previously observed using conventional fusion, a 23 MeV gamma emission has been detected. This radiation results because fusion of two deuterons produces only one product nucleus. Gamma emission is required to conserve momentum. Because this gamma energy is not detected during claimed anomalous energy production, most critics dismiss the claimed helium as being an artifact. The other two branches more frequently observed during conventional fusion are apparently not the source of significant energy in this environment. This distortion of expectations also adds to the skepticism.
15) To be successful, a theory [explanation of cold fusion] must answer at least five basic questions to explain the P-F effect and several other questions if the entire range of published observation is to be explained. (a) What mechanism allows the Coulomb barrier to be overcome? This question is basic and will have to explain how nuclei as heavy as palladium can suffer a reaction with nuclei as heavy as oxygen, in addition to the proposed fusion between deuterium nuclei. (b) What mechanism distributes the released energy throughout the lattice rather than requiring it to be focused on a few individual particles? This mechanism must also explain why some nuclear energy is retained by the nuclear products when these products are produced very near a surface. Otherwise, charged particles having significant energy to leave the material would not be detected. (c). How is the proposed mechanism related to the physical environment? Most present theories assume the nuclear reactions occur in b-PdD having a composition near PdD1.0. The model must explain why anomalous reactions occasionally involve other materials and why the required conditions are so difficult to achieve. (d) What nuclear reaction is the source of observed helium? Fusion is not the only conceivable source of helium as a nuclear product. (e) If helium results from a fusion reaction, what mechanism allows conservation of momentum and energy, and what mechanism distorts the reaction paths to produce helium rather than neutrons and tritium?
16) Calorimetry is a well understood technique which has been applied in various forms for over a hundred years. A vast literature of chemistry and physics is based on such measurements. While measurement of power at the microwatt level is a challenge, measurement of watts, as is being done here, is not considered difficult. Prof. Hansen has suggested that a calorimeter cannot be trusted unless it has demonstrated accuracy in measuring the heat from a known reaction. This is a fair request provided absolute calorimetry is used. However, as noted at the beginning of this review, relative measurements are actually being made. Stability is the only requirement, a condition which is much easier to evaluate and much less prone to hidden error. This is not to say that all claims for anomalous energy are correct or accurate. The question which must be examined is whether some studies are sufficiently correct and accurate to demonstrate the claims to be highly probable, not necessarily absolutely certain. When such evaluations are made, the critic needs to keep in mind the potential magnitude of suggested errors. Just because an error can be imagined and justified does not mean it can explain multiwatts of apparent power production. In general, the magnitude of the effect has frequently overwhelmed any plausible errors or prosaic explanations. The statement that the claims are not convincing is often heard. While this euphemism is actually a gentle way of saying, ”I just don’t believe you,” one needs to ask just what is not believed and just what deserves additional study. Is it rational to reject everything just because some part does not make sense? Would it not be better to support some focused work on the subject to answer a few basic questions? What are we to make of the consistent patterns of behavior as well as the influence of material properties and the presence of helium, a possible nuclear product? Is it reasonable to believe that numerous independent studies show the same patterns just because of chance? While such arguments are not a proof, they are commonly used by prudent people to evaluate all aspects of life. Indeed, this is the rationale behind requiring many duplications of a claim, a condition which has been met in this case. When a new phenomena is evaluated, a belief system based on probabilities needs to be adopted. An absolute rejection or acceptance is not useful. The issue is whether the likelihood of the phenomena being real is sufficiently large so as to justify further work. In the case of the CANR claims, I suggest further study is justified.
17) CONCLUSION: The claims for anomalous energy production using electrolysis of heavy water have been evaluated and found to have a high probability of being caused by a novel phenomenon. In addition, the most likely source of the heat is a nuclear reaction which produces helium. This nuclear reaction is not normal fusion and it does not follow the rules required by conventional theory. Numerous models have been proposed to explain the observations, but none at the present time can account for all of the reported behaviors. More work is required to determine which of the behaviors are part of this novel phenomenon and which can be explained by ordinary processes. However, the claims have now reached a level of understanding which justifies a reexamination of the published work and attention by the scientific community.
References
1. “A Critical Evaluation of the Pons-Fleischmann Effect (Part 1), E. K. Storms, Infinite Energy 6, #31, p10 and #32, page 52 (2000).
2. Available from the library of the LENR-CANR web site <http://www.lenr-canr.org>