It seems you are conflating two processes when only one will suffice. And one of them is absurd from the start.
Why pump the liquid at all? Why use a magnetic field with pumping, when a simpler route exists? Calutrons were a gigantic waste of money in the Manhattan project and were only used for a few years as an expedient. Centrifugal acceleration (even the common lab centrifuge) should give similar or better results, if what you want is enrichment by density gradient in a NiCl solution. In fact the chloride is ready-made for this since by varying the water content and temperature (solubility) - the heavier fraction can be solidified by chilling - while the light fraction remains a liquid and is more easily removed at the early stages (to automate the process). If you are going for enriching an isotope that is 10% denser, it will take at least seven stages for every doubling (not counting losses). This is the "rule of seventy" (similar to formula used in compound interest). Therefore, to increase a 1% isotope to 16% might require a minimum of 28 stages of progressive enrichment, but when losses are included, it is probably closer to 50 stages. Automation makes a big difference with this many stages. For the NiCl solution (hexa-hydrate) the solubility is 254 g/100 mL at 20 °C - and 600 g/100 mL at 100 °C. That difference could help a lot in automating the processing, so that even 50 stages in a continuous centrifuging would not be a insurmountable problem to get 64Ni enriched to a level in the mid-teens at an affordable cost. At least this is doable, but - as for final cost - that is another question based on many issues. But if the enrichment percentage can be kept to a low level, it need not be too expensive for the numbers Rossi is throwing around. This is because with NiCl - the rejected isotopes are of the same value as the feedstock, and this makes the processing simply a matter of overhead, efficiency and labor. The bulk nickel is no less useful in industry - with the 64Ni removed as with it there. In effect, you only "rent" the feedstock, removing very little. That is a huge difference compared to what we look to as the "model" for isotope enrichment. With uranium enrichment - in contrast, the feedstock cost must be 100% absorbed in the cost of the enrichment (since the depleted U has almost no value) so that factor alone grossly inflates the net cost by several orders of magnitude (compared to nickel). Enrichment cost alone, for even the heavy metals - is not outrageous so long as there is a large market for the depleted feedstock. That is key. There seldom is a market, but since nickel has that as its major feature, then an enriched isotope on a mass production scale, for a NiH energy system, is not out of the question. -----Original Message----- From: Berke Durak On Thu, Nov 3, 2011 at 2:52 PM, Peter Heckert <peter.heck...@arcor.de> wrote: > The ion diffusion speed in an electrolyte is only some centimeters > per minute at best, while the speed in a Calutron is probably some > 100 to some 1000 kilometres per second. > > Therefore the mass inertia of the nucleus at this low speed has no > effect. The electrolyte vessel must be some 1000 km long for this > to work. Yes, but can't the liquid be accelerated to a sufficient velocity using pumps? A quick search reveals that the radius of the circular path described by a charged particle subject to a transverse magnetic field is R = mv/qB where m is the mass, v is the velocity, q is the charge and B is the field in tesla. Assume we want to separate two isotopes of masses m1 and m2, we'll want R1 - R2 > d for some sufficiently large d. Take d = 1cm, m1 = 58 amu and m2 = 64 amu, and q = 2 x 1.6e-19 C (for Ni 2+), then we need v >= qB/(m1 - m2) = 32e6 m/s/T. For a 100 nano tesla field, this gives 3.2 m/s and R1 = 9.6 m and R2 = 10.6 m. I suppose 3.2 m/s is a reasonable velocity. If we pump the solution so that the Ni2+ ions reach a velocity of 3.2 m/s while keeping the magnetic field around 100 nanotesla, we might be able to separate them. By properly orienting the setup with respect to the Earth's magnetic field, some mu-metal shielding or using some active cancellation technique, it might be possible to obtain a 100 nT field. The problem might be that you will also have whatever cations are present swirling in the opposite direction. I don't know how that would affect the Ni2+ ions. Any physicists / electrochemists in the room? -- Berke Durak
