On Sat, Sep 22, 2012 at 10:19 PM, David Roberson <[email protected]> wrote:
I would be concerned about the cost of platinum. Stainless steel might > work since it is un reactive. The problem of cost is an important one, since we're talking about a tabletop experiment. The danger of falling back upon "unreactive" materials such as gold, carbon and stainless steel is that they are only relatively inert under chemical reactions. Under proton or deuteron capture, for example, they are quite reactive: - 197Au + p -> 194Pt + α + 8.4 MeV - 197Au + D -> 199Hg + 11 MeV - 12C + D -> 13C + p + 2.7 MeV - 52Cr + p -> 53Mn + 6.6 MeV (chromium is an ingredient in stainless steel) I appreciate that there is no consensus on this list that proton and deuteron capture are taking place, and beyond that, there is incredulity. But people such as Ed Storms take the possibility seriously, and the numbers are very suggestive when one looks at the transmutation results in the aggregate. So if it might be the case that these processes are occurring, this dimension can be included in a search for suitable controls as well as possibly being used for further investigation. Not taking it into account could lead to frustrated attempts to find a blank -- and it occurs to me that this itself is an interesting detail. Taking a second look at carbon, I see that it is inert under proton capture, so graphite might actually be a good choice or hydrogen-1 after all (but not hydrogen-2). But at the moment I'm looking at data for an experiment in which palladium was used with hydrogen-1; along the lines I've been suggesting in previous posts, this would be a good combination for a control run, since proton capture is not energetically favorable in palladium. This turns out to be too simplistic an approach, however; in the case of this experiment, the choice of electrolyte, Na2CO3, appears to have been important, and isotope shifts in the vicinity of sodium were observed, in addition to many others. For similar reasons, the material of the container could be important -- teflon (with carbon and fluorine in it), pyrex (with boron) and stainless steel, for example, might all be susceptible to whatever processes are taking place within the active material nearby. So if proton and deuteron capture are occurring, the search for a control may need to take into account not just the substrate and the isotope of hydrogen, but the composition of the electrolyte and container as well. Once we start talking about deuterium, the search for a control system that meets the present criteria becomes nearly impossible, because deuterium can combine in exothermic reactions with itself. Under those circumstances, going with the present assumptions, the substrate need not be anything more than a matrix that facilitates the various reactions. Eric
