Week+of+6-11+to+6-15

6-11-12 I began the day by measuring the resistance of the gold sample prior to adding silver paint and connecting the wires. Its resistance read 1.0 Ohm. The silver paint had hardened when I tried to use it. I talked to Matt about it and he suggested that we add Acetone as a solvent. I did so and it became slightly liquid-like. I put the silver paint on the gold and connected the two wires I had already cut. I measured the resistance from the ends of the two wires. I kept getting ridiculous amounts of resistance. It read anywhere from 15-350 Ohms. I think this was either caused by the silver paint not being dissolved in the proper liquid and not being as conductive or by the wires not having cleanly cut ends. Professor Kandel suggested connecting the wires to the gold through the use of solder. We soldered the wires to the gold with Indium. Also, I attached a thermocouple to measure the change in temperature when voltage is applied to the sample. We brought the system over to plug in to a Variac to test it. Matt accidentally plugged it into a wall outlet rather than into the Variac. The gold system received 120 V and subsequently exploded. We soldered the wires again and this time placed the plug correctly into the variac. I moved it very slowly up to 5 V. The thermocouple read 26 C before any voltage was applied. The temperature jumped very quickly and rose to 95 C after only a few seconds and before I even made it to 5 V. I turned the variac down to 0 V. We tried to measure the temperature increase again but with a smaller amount of voltage charged but we found that the circuit was not complete. This is most likely because, at the connections, the indium possibly reached a high enough temperature to melt and ruin the circuit. Matt thought it would be best to just connect the wires with epoxy and he did so after I left and let it sit in the oven overnight.

6-12-12 I came in and Matt and I were going to continue testing th esystem with the sample connected by epoxy to the wires. He had me connect the thermocouple to the sample using superglue because he tried using epoxy on it and it would not work. While doing this, one of the wires that was connected came off with the epoxy and gold beneath it. Afterwards, we discussed a sample holder with Alex to use on Annette's old scope. Matt showed me how to use Autodesk on the computer to create 3-D models. I created a model of the sample holder along with the washer that will be placed on top of it.

6-13-12 I began today by using the hole puncher to create washers to utilize for the new system. Matt purchased a nylon washer but realized that the melting point is too low for what we could be possibly doing with the temperature increases. I made the washers with mica from old samples of gold. When we tried applying them, however, they were too flimsy and broke easily. We looked for a ceramic washer in the lab and Kevin made us one out of alumina. Then,I used epoxy to attach the washer to the sample holder. I placed it in the oven right before lunch; it should be done drying later today. When I got back from lunch, I cut holding clips for the sample holder and punched holes in them. 6-14-12

I came in today and spent about an hour and a half learning about Annette's old scope from Matt. (After that, I spent about an hour working with and getting familiar with the setup. I took scans messed around with the electronics to get comfortable with the new system and train myself to be able to combat strange occurrences). After that, I attached one of the clips I made yesterday to the new sample holder. 6-15-12 I spent the first half of the day taking the safety class and getting my work permit. I only stayed for about an hour because I had to go to Columbus, OH at 12:30. While I was in the lab, I continued adjusting the sample holder clips and messing around with different shapes for them.