Hello all, I use an evaporation chamber at my lab every day. Basically, put some substance in the chamber, close it, bring it down to vacuum, and pump enough current through it to vaporize it where it deposits on a substrate. I've been using 175A to create a deposition rate of about 1 angstrom/sec. All of a sudden, a few days ago, 175A doesn't generate any deposition. Even if I bring it up to 200A, there is almost no deposition taking place. I've checked the electrodes both physically and with a DMM to the best of my abilities, and there doesn't appear to be any loose connections or damage. I've also ruled out the possibility of the rate monitor being faulty. Does anyone have experience with evaporation chambers who could help me out?