Things have no started particularly well. We’ve had problems with both the sample and the beam. My first sample doesn’t look at all “right” when put in the beam. It looks like gold, it feels like gold, it smells like gold (does gold really smell?), but put it in a beam and it doesn’t really behave like a duck should, ermmm... like a gold crystal should. That’s been frustrating enough, but the beamline may be giving us trouble in a new way.

Anyhow, there has been some progress. The big piece of equipment that moves our samples around is aligned and calibrated (the diffractometer). The heating equipment functions, the gas flow controllers function, and the plumbing is done for the water. Now we just need to get the sample to behave. Hopefully that shouldn’t be too hard. On a normal day that means just heating the sample up to around 1200 degrees Kelvin. At that temperature most anything that’s not gold will have left the surface and the atoms themselves will have enough heat energy to rearrange. The atoms in the bulk usually “repair” their arrangement to some extent. Gold is so soft that virtually any time it is handled the crystal begins to suffer from the forces and the crystal loses some of its regular atomic lattice. High temperatures help remove those internal clumps, stresses, twists, bunches, etc... and restore the more highly ordered spacing. However, for us the most important thing is that the high temperatures provide enough energy for the surface atoms to rearrange into the interesting patterns we hope to observe and manipulate.

Unfortunately things have not ended well for the day. As I leave the APS, turning the experiment over to the night crew, the beam has been lost and we have no light. No light = no experiment. We’ve done about all we can do without light, so it’s a matter of waiting.

and Yes, yes... it’s still October. In fact it’s not even Halloween yet. But since most of the run will occur in November, I’ll keep this as November.