Week 3 Post 2

The calculations which were necessary to make the entire procedure possible were nothing over the top, but instead an application of one of the most fundamental, and important formulas that relates gases: PV=nRT. By manipulating this formula, then finding the inside diameter of the copper tubing, we were able to create a formula which had only one variable, which was length of the copper wire. Trying to get as small as possible, without being too hard to work with, the optimal choice of length was 4 inches. So the process began... we attached two of the best valves we could find to either end of the 4 inch tubing and connected the whole thing to the original system we used to fill the 150cc canister. Luckily, we had filled the 150cc canister with 20psig of gas meaning we had enough purified helium in the canister to fill the 4 inch tube. So the canister was attached at the other end of the 4 inch tubing and valved off so we could safely pump and purge the 4 inch tubing. We did all the plumbing with of the copper lines, and finally got it all set. We hooked up the pump and leak checked the whole system. We wanted to purge the whole system with purified helium a few times to ensure that there was no air contamination in our 4 inch tube. So we passed some additional underground gas through the zeolite and passed this purified helium through the 4 inch tube 3 times. Once we finished pumping and purging. We pumped down one final time and on Monday we will move the helium from the 150cc canister into the 4 inch tubing.