ASU Analytical Trip (August 11, 2010)

So, after returning from my east coast trip I worked for a while under Dr. R until it came time to take another trip to do analytical work on another university's equipment. This time we headed to Arizona State University to use their SIMS - Secondary Ion Mass Spectrometry - machine (a CAMECA IMS 6f).

Our samples were predominantly quartz crystals of Dr. R's student CD, who placed the crystals onto mounts and polished them down until they presented flat surfaces exposing melt inclusions.  These mounts are placed in a holder, and all of this is sputter coated with gold.

 These crystals were then bombarded with oxygen ions so as to ablate the polished surface ionizing some of the ablated material and sending it through an energy filter to sort by ionization and a magnet to sort by mass before collecting a target ion.

 In our case, trace elements of about twelve types were of interest to us, particularly Ti.  Using our knowledge of the volcanic setting these quartz crystals formed in and the Ti concentrations of the inclusions we were able to show that current Ti-in quartz barometers, thermometers, and thus analogs for depth do not effectively describe realistic values for CD's quartz samples.  We also got an abundance of trace element information to help characterize the different categories of inclusions we came across.

While we ran our multi-day analytical sessions we had a maintenance crew who was doing work on the building unplug one of our pumps to create vacuum in the machine and so it crashed, which definitely freaked CD and I out.  Luckily it was an easy fix and though we missed a bit of run time in order to let the machine pump down we were analyzing samples by the next morning.

Additionally, the lab manager was kind enough to give me a tour of all their nearby equipment which included another, older SIMS machine, a TIMS machine, and a high pressure high temperature multi-anvil ram that I found really awesome.

We were lucky to have a bit of rain ease away the 100+ °F heat we had most of the time and I managed have dinner with an old classmate and her husband who had moved to Phoenix the year before and see how they were.  Overall, it was a fascinating trip and it was a real treat to see some equipment that was not directly related to our work while at ASU.  The SIMS lab staff were excellent and we had some got some excellent data, which is what these trips are all about.