Week+of+2-11-2013

2-14-13 I came in today and once more worked on trying to get the scope to retract. After a long, unsuccessful approach of about 2500 steps, I rotated the sample and cut a new, longer tip. Another unsuccessful approach of 3000 steps followed this change. I then forced the sample to crash into the tip and then pulled it slightly back. It was able to approach this time in 104 steps. I tried to force the tip to retract by adjusting a number of settings, none of which was particularly successful. I decided to let the fast out procedure run for an extended period of time. After about ten minutes, I stopped the retraction and found that the STM was no longer tunneling. I approached to see how far away the tip had gotten and it only took 5 steps to approach. Essentially, the retract feature on the scope does indeed work it just works incredibly slowly. I tried this a second time and gained the same result. I think that this is due most likely to the sample holder being too heavy which is preventing the microslider from moving the tip back and forth inside the scope. After informing Matt of this, he told me that he intends to create a lighter version of the tip holder to solve this problem.