From: Bob Higgins
I believe in this vintage of the HotCat, the central axis was open to flowing environmental air. That is why the inside of the stainless inner tube would be painted black - to help with radiation from the inside (not that there is very much radiation - only from the ends). The central axis would mostly deliver heat via convection. The 2 coaxial inner tubes (that appear to be only a single tube) is the only logical place to contain the ingredients. Penon lists the components and there were only 4 observable components. As a welded unit, the central cylinder would appear as a single part - the welded coaxial reactor cell. Bob - This would be easier to imagine if it wasn't explicitly stated that "The most important element of the E-Cat HT was lodged inside the structure. It consisted of an AISI 310 steel cylinder, 3 mm thick and 33 mm in diameter, housing the powder charges. Two AISI 316 steel cone-shaped caps were hot-hammered in the cylinder, sealing it hermetically." IMO - the 3 mm wall thickness at the operating temperature would simply fail immediately without a ceramic retaining structure, and the "cone shaped" caps seem to preclude another coaxial tube. Jones
