Week+of+11-6-2012

11-6-2012 I came in today and found that the undergrad Chris had been scanning. I looked at his last scan and logbook and decided to change the tip. I then began scanning unannealed gold in an effort to anneal it through my heating experiment. Chris had been having some problems with approaching earlier today as indicated by his logbook and they persisted through my time in the lab. When I first approached, the STM never recognized that the tip had actually made contact with the surface. The STM continued to approach and since the sample was stationary, the tip was getting shoved further back into the tip holder. By time I had checked it after around 2000 steps, a somewhat normal amount for an approach on this scope, it had been shoved into the tip holder past retrieval. I tried to get it out and just pushed it in even more. Matt tried to solve this by using a drill bit to fish the tip out but he was also unsuccessful. Tomorrow, I will attempt to scan with the tip stuck inside of its holder and the designs for the new scope should be finalized by this Friday. Construction should be able to begin next week. 11-7-2012 Unfortunately, the scope's failures persisted today. I came in today and placed a new tip in its holder and tried to approach the same sample of unannealed gold from yesterday. The first time I tried to approach, it got to around 2000 steps before I stopped it to check on it. When I opened the box I found that the tip had not yet reached the surface, though it was close, so I tried a second time. I let the scope approach about another 1000 steps before checking on it again. I found this time that the tip had indeed crashed into the surface and the sample's stationary stance was pushing the tip further into the tip holder. I was able to pull the tip out before it was too far in to get stuck. I tried to approach after this and found no luck as the same problem occurred. For some reason, the scope is not tunneling correctly and is not recognizing when the tip has made contact with the sample. Perhaps it is some internal connection problem. Finally, at 5:15 pm, the scope successfully approached. Unfortunately, the scans were absolutely horrid. I could not find any way to fix the Y-slope. I tried adjusting the gain, moving the scanning area, adjusting the A/D gain and nothing worked. I tried retracting the tip 20 steps and tapping the sample to try and get a better area but it would not approach again after that. I knew it wasn't working when it went past 50 steps in its approach. Also, I should note that the sample in that area was probably horrible because of the repeated crashes in that particular places that occurred on accident because of the scope's current inability to recognize the surface. Depending on Dr. Kandel's approval of the designs, Matt should be able to begin building the new system which will use a Peltier device to heat the sample. The scope will also be in air but will be in a much smaller setup than the current one. It will be much more suitable for my heating experiment.