The core appears to be two parts or elements making one assembly, a chamber for solid fuel with the ability to withstand a specific maximum burst pressure (comment from Lui needed) structurally and in addition have a seperate piece of stainless steel retaining the glow plug which is also used to seal "the chamber" made out of copper. This is a 2 peice configuration of unlike metal which would need to be sealed together threadibly. Comment appreciated from Lui in regards to solid copper billet and omit the stainless steel.
It also appears these cores are placed within a holding framework "like a skeleton frame" in a bath of water, does this container that is designated as copper in the power point also need to hold pressure?
The tray, is it sealed and bi directional flow?