I believe the ends are completely sealed with a compound like the Vitcast 1400 INS-H. I also think the space between the inner and radiating tube is probably filled with this same compound. You don't want air flowing in there in case there are cracks in the alumina adhesive put over the heater coils. You don't want those coils exposed to O2 or they will fail immediately when over 1000C.
I have done a detailed weight analysis of the assembly I posted, including three coils of 30 turns each of 20 gauge Kanthal APM heater wire. The weight comes out about 15% below the measured weight of the Lugano tested hotCat, but that could easily have been made up by using denser casting compound filling the inside of the mounting cylinder "end caps". Also, the radiating tube, being a custom cast piece probably weighs a little more than the stock extruded tube of approximately the same dimension. I am pretty sure this is all on the right track. Of course, these mechanical details of the Lugano tested hotCat are the least important. Most important is what is used for active LENR powder that is pre-sintered inside the central tube. My opinion is that we haven't seen any of this in the analysis of the starting material or the ash. The starting material (as I have posted) is likely just the consumable portion (perhaps with some Ni for inert obfuscation) and what shook out as ash was never the active material which is all sintered onto the inside of the central tube. Replication would certainly require a good estimate of what this active media is on the inside of the central tube. Bob On Wed, Oct 15, 2014 at 12:08 PM, ChemE Stewart <cheme...@gmail.com> wrote: > Me too, good job. Tube in a tube reminds of the model rockets I used to > build. Fin supports between tubes might explain the wider dark band seen > as a spiral?. Do you think a lot of the heat might be discharged in a > space between tubes and out the ends? Or are the ends completely sealed? > > On Wednesday, October 15, 2014, Jed Rothwell <jedrothw...@gmail.com> > wrote: > >> You & Alan have done an amazing job sleuthing out the details of this >> thing. I suppose you are right, although I cannot tell. If you are right it >> is a great job and if you are wrong you have a vivid imagination! >> >> - Jed >> >>