Return to the clickable list of items
108) Another experiment for students ?
Ludwik Kowalski (August 31, 2003)
Department of Mathematical Sciences
Montclair State University, Upper Montclair, NJ, 07043
1) The cold fusion experiment for students, described in item 103, focuses on excess heat. Let me describe an experiment for students which some of you might be able to perform. It was inspired by the talk of Dr. Richard Oriani at the 10th International Conference on Cold Fusion, by a conversation with Dr. John Fisher (also at ICCF10), and by an email message received from Oriani after the conference (see below). This experiment is designed to reveal alpha particles resulting from nuclear reactions presumably taking place during the electrolysis. An ordinary tap water, rather than expensive heavy water, was used to prepare the electrolyte.
2) Alpha particles were detected in plastic chips similar to nuclear emulsions (but much less expensive and much easier to use). The detector is called CR-39; it is a sheet of transparent plastic. Alpha particles, for example, from radon, create latent tracks which can be made visible (through a microscope) by developing the chips in hot KOH. The CR-39 detectors are commercially available from several suppliers. One place to obtain them is:
Track Analysis Systems Ltd
H H Wills Physics Lab
Tyndall Avenue
Bristol
BS8 1TL
U.K.
Tel (0)117 9260353
Fax (0)117 9251723
web www.tasl.co.uk
e-mail apf@tasl.co.uk
Here is what this supplier wrote to me in January 2003. “Thank you for your inquiry. We do not have any agents in the US -- we sell directly to customers. The prices depend entirely on what you require. If you can say the sizes and quantities you are interested in, I will be pleased to make a specific quote. For example: pieces 25x25 mm, with an engraved (incrementing) number, cost 1.75 US dollars each. We can quote for sizes from 10x10 mm up to 275x280 mm. Our material is carefully produced to high quality standards, and each batch of production is tested for background and track response. For the US, we have a minimum order quantity of 100 US dollars.”
3) To gain experience I exposed a CR-39 chip to a 241Am source of alpha particle (removed from a fire alarm detector). After an exposure of 30 seconds the chip was kept in hot KOH (70 degrees C) for six hours. Then it was washed in water and placed under an ordinary microscope (magnification 40 or 100). Pits due to alpha particles were visible in the exposed area while the surrounding areas had much lower track densities. These detectors are often used to measure concentrations of radon in different locations. Dr. Oriani placed the chips into the electrolyte of a cold fusion cell and observed an excessive number of tracks. Here is what I wrote to him after the conference: “I am a physics teacher who is trying to develop a convincing cold fusion demo for students. Your CR-39 experiment is a good candidate. I talked about this with John Fisher and he suggested that I contact you about details.
1) What was the concentration of Li2SO4 in water?
2) How many volts and how many amps?
3) How large were the areas of your Ni and Pt electrodes?
Suppose I do an experiment under about the same conditions as you did and that no extraordinary event (which you described) occurs. I want to bring the number of alpha pits to at least 10 per field of view (magnification 100).
4) How long should a CR-39 be kept in the tube (days, weeks, months, ...) ?
5) Is it better to keep CR-39 in the liquid or above the liquid?
Here is Dr. Oriani’s reply: “ ... It's a pleasure to answer your questions because I am delighted that you will try to convince your students that so-called cold fusion is a real phenomenon. Answering your specific questions:
1) The concentration that I used is 2.3 g of Li2SO4 in 100 cc of H2O, but you can deviate from that to some extent.
2) I usually electrolyzed for 3 days starting at about 100 mA, the next day at about 200 mA, and the third day at about 300 mA, letting the voltage be what it needs to be to achieve those currents.
3) The cathodes were bounded by an O-ring whose diameter is 1.4 cm, and the anode is a flat Pt spiral of about 1 cm diameter. The CR-39 detector chips are suspended within the electrolyte preferably above the anode, or in the gas in a heated section of the electrolysis cell kept at about 65 C and separated from the surface of the electrolyte by a nickel disc of diameter slightly less than the id of the electrolysis cell. Its purpose is to mitigate the impact of electrolyte mist upon the chips.
4) The detector chips should be in the cell for the entire duration of the electrolysis. I suggest that you place chips both in the liquid and above the nickel disc in the vapor.
5) You must remember that radon in the air and cosmic rays will produce tracks on the chips during handling and photography or viewing under the microscope. Hence you must examine the chips by etching in 6.5 N KOH at 65 C for about 10 hours and recording the tracks visible before electrolysis, then do the electrolysis and repeat the etching and examination of the chips at exactly the same areas that you examined and recorded prior to electrolysis. [I suppose the photos taken before the electrolysis were compared with photos taken after the electrolysis.]
6) Of course you also need to carry out controls, doing exactly the same operations to the control chips as for those exposed in the cell, but the control chips are not exposed to electrolysis. For further details I refer you to our paper published in Jap. J. Appl. Phys. [in 2002] and available at www.lenr-canr.org I hope that you succeed. Feel free to write again if something is not clear.”
In the correspondence that followed Dr. Oriani provided me with data shown below. Referring to the table he wrote: “The numbers are new tracks per cm2 of chip area. That is, I count the tracks that appear after electrolysis and the second etch and subtract from that number the tracks that appeared after the first etch before electrolysis and divide that difference by the area on which the tracks were counted. [The results are shown in column 2]. Exactly the same area was counted after each etching. The same procedure was applied to the control chips; they were immersed in solution of the same concentration as were the actives, in fact from the same batch, the sole difference being that they were not exposed to electrolysis. [The results are shown in column 1]. If you want the absolute number of new tracks, multiply the tabulated numbers by the area of a chip, roughly 0.64 cm2. Note that the data entries were artificially organized in order of decreasing magnitude. All experiments were done with solution from one large batch.”
Oriani and Fisher
published in July 2002
Controls Actives
=====================
541 3760
260 2756
260 2375
221 1733
204 1138
195 962
177 962
165 897
143 757
143 676
118 578
108 543
95 318
95 315
75 260
59 225
As indicated by Oriani, the lines in the above table have been sorted according to new track densities; a monotonic decrease of densities in 16 consecutive experiments would be very unlikely. The second column shows that a single 3-days exposure produced very different new track densities when experiments were repeated. Commenting on this Dr. Oriani wrote: “The overlap of the two distributions is owing to two facts: not every electrolysis [experiment] produces a nuclear reaction (I do not know the reason), and the reaction may have taken place away from the chip. This second reason is a strong possibility because I often see one side of a chip with a large number of tracks whereas the other side has only a number characteristic of the controls. I appreciate that for a demonstration you would like an experiment that always produces the expected result. However, we are not yet able to have that assurance in this field. Because of the two reasons discussed above we must rely on a statistical analysis of a large number of experiments unless, as you say, one gets lucky and sees a ‘shower’ as I showed in my lecture.” Yes, reproducibility is a big issue, as in most cold fusion experiments.
I do not know how to explain large changes (order of magnitude) in new track densities from control samples. It is significant that the method used allowed to discriminate against tracks which were formed in CR-39 before experiments. Would the use of distilled water be preferable? It depends on the role of impurities in cold fusion phenomena. Several scientists speaking at the conference (ICCF10) think that successes and failures of cold fusion phenomena depend on uncontrollable impurities, often below the ppm level. The results presented by R. Oriani and J. Fisher are remarkable because new track densities in control samples are always much lower than corresponding densities in active samples. At least this aspect seems to be highly reproducible.
Knowing that I plan to share his data with other teachers Dr. Oriani wrote: “you have my permission to share and operate on these data in any way you please.” In a message commenting on the draft of this document he added: “ I hope that your web site causes someone to replicate the experiment.” I also hope that this will happen. It would be a great student-oriented project. The task is well defined: to confirm or not to confirm results published in a refereed journal in Japan. I think that the journal would publish a serious study of that kind. Too bad that I did not meet Dr. Oriani when I was learning how to use CR-39 detectors last spring (for an experiment which turned out not to be necessary). I was on sabbatical at that time; now I am too busy teaching. Perhaps I will have more time in the Spring semester, or after I retire in May of 2004.
POST SCRIPTUM:
The CR-39 detectors can be cut into small pieces, for example 1 by 1 cm, by using regular scissors. They can also be labeled by using a sharp needle. No darkness is required, as with photographic emulsions. A team of Russian scientists (A. Lipson, now working in the University of Illinois, and A. Roussetskii, from Lebediev Institute in Moscow) managed to distinguish alpha particles from protons by using CR-39 detectors in combination with very thin filters. But such task is much more difficult than with nuclear emulsions. The unique advantage of CR-39, as illustrated by R. Oriani and J. Fisher, is that a chip can be “developed” twice.
Suppose the first development produced 37 tracks near a recognizable scratch on the detector’s surface. This is the background due to previous long time exposure to radon, cosmic rays, etc. The chip is then used in an experiment and developed again. The previously seen tracks are still visible but an additional set of new tracks appears, for example, 10. Then we know that new tracks are real; they were created when the experiment was performed. This approach is much better that using two different chips, that is: getting 47 from one chip (background plus signal), getting 37 from another (background only) and subtracting these two numbers to get 10. The net result obtained in that way can not be distinguished from statistical fluctuations.