in order to improve the stability of the chamber temperature the current plan is to add a heater and insulation for the second chamber. room temperature changes were about 2K_pp over the last couple of days. I already ordered flexible insulating foam for the chamber (the round parts). What we need is one or more heaters. We could somehow add half of the original heater to that chamber but i would like to go for a more final solution as we need one for the other chamber in the ATF as well. The plan is to buy standard heaters with adhesive backside and stick them to the chamber.  Price is about $70 for a 10"x10" heater (MINCO). The chamber surface is about 22"x25" in total, cut into smaller areas by the 4 vaccum tubes and 2 legs. I think we can cover most of it with a total amount of 4 to 6 heaters of different sizes.