over the weekend we baked the two AR-coated windows for the new chamber. Bob doesn't need the oven the next couple of days so i restarted the baking again and will continue to bake the remaining parts the next couple of days. We also set up peters old vacuum pump. We got lots of stuff from 40m and cleaned all parts today. The pump is now running and pumping the whole system including the hose to the chamber. We also wrapped some heaters around the parts and started heating the stuff to make it a bit cleaner as no one knows for what the parts have been used before. They all looked pretty clean and wiping everything didn't show any obvious contamination. We can't bake it to high as some parts are viton sealed.
The new, insulated feet should be finished by wed or so. Tomorrow we start cutting the remaining foam to size and glue the parts together. I ordered the remaining heaters, one is already attached to the chamber and it fits good except that the sticky back is not sticky enough to hold it in place. The bending force is too high, so i added some aluminum tape which holds it in place now (the corners didn't want to stick). We have plenty of space for temp sensors and we will add several AD590 and a couple of platinum sensors. If we find out that the AD590 is not good enough we can easily switch to the other sensors. We should discuss how many we want and especially where. My guess is that we should add some more on this first prototype to get a feeling for the gradients or so. We can then reduce the amount on the second chamber if we want. The platinum sensors are cheap. Typically one is about $8-10 each, but I bought a pack of 100 directly from the manufacturer and so its about $1 each only. |