Hello, I'm a student at the University of Minnesota and as I was moving out of my dorm last semester I found a co2 laser in the throw away/donate electronics bin my dorm has set out. I don't know it's exact condition and I'm not an expert at gas lasers. It seems like most of the laser is in order but there a few things that might be messed up. The person who had it before seemed to have been taking it slightly apart for some reason. They took out a bunch of the screws that were holding stuff together which were also grounding screws. Those will be easy to replace though. At this point I'm actually kind of hoping some other student stole the laser and just threw it in the bin because they didn't want their parents to know when they moved out. That means it's much more likely it still works. But there's a chance it was thrown out because it's broken. In any case here's the main problem: 1. What is the foil that runs down the outside of the gas chamber tube for? It appears to be made of copper and it used to be grounded. Whomever had it before ripped most of it off but I can tell it ran down the entire tube because there's sticky residue where it used to be connected. 2. Is there anyway to test the laser without co2 being pumped into it? I know the concept behind a laser (I'm a physics major) but I'm quite a novice in general when it comes to lasers. I'd rather not spend the money to pay for a system to pump in the co2 without knowing whether the laser was in the bin because it's beyond repair in some way or not. Anyway, thanks for your help!