We basically got no where last night, and basically the day shift didn't make it any further either. We've lost now fully 3/8ths of our beamtime because we the beam of photons and the diffractometer refuse to line up. Sadly, this is not something that users should be doing. In an ideal world, we would just come in, set up our experiment, and do science. That's not really the case in practice, but usually things go smoother than this. We still have to struggle, but usually we're struggling with the experiment and not basic beamline function.

Regrettably the diffractometer motors frequently lose their positions. And by frequently, I mean that two of them seem to lose track every time they move.

This is further complicated by the fact that the photon energy, the wavelength of the light, is A) not as advertised, B) not constant, and C) drifts in position. The beam of x-rays that comes from the storage ring has lots of different energies, most of which we don't need. So there is a device called a monochromator that selects out a particular energy that we want. The x-rays dump an enormous amount of heat on the monochromator mirrors. Usually there's a fairly reliable cooling system that adjusts the angles, correcting for aberation due to the heating. Unfortunately this is not the case. So we suffer from a beam of photons that is not the energy we request. The energy of the beam fluctuates and its position at the diffractometer also change. Such problems may be fatal to the experiment at hand...

So we're not very happy at the moment.

We'll try to make the best of it.