California

Happy new year all!

I've been in California this past week and have another week to go. It's another trip doing experiments at the Stanford Synchrotron. They have made a few upgrades to the facility, some of which are good and others which were not so good. For example, they now run the electron beam (which generates synchrotron X-rays as the electrons are deflected using magnetic fields - we use the X-rays that are produced to do experiments) in what is called 'top-up mode'. It used to be, the electrons would be injected 3 times a day, but then over time some of them are lost due to a variety of reasons. So over the course of 8 hrs between fills, the electron beam current - and therefore the X-ray beam intensity - would drop by about 40%. Now they top up the electron beam every 10 minutes, and they are running at a higher current than before, so all in all it generally means more stable experiments with no interruptions for the beam fills. So this is good; however the beam line (experimental station) we have been using for the last few days has not liked us for some reason. The X-ray beam shape and position seemed to move around, which was really annoying. Then the computer developed some kind of hard disk and/or power supply error (mind you, it is pretty antiquated so probably not surprising). Last of all the chemistry didn't work as well as we had hoped. But true to form, all the best results were obtained on the very last night at about 2 am.

Now I have 2 days off and am planning to veg out a bit, probably go for a short drive this afternoon, and generally rest up ahead of the next stint. On Wednesday we change beam lines and start new experiments. We'll be using the same chemistry etc. but it's a different technique: small-angle X-ray scattering, or SAXS for short. Probably the most provocatively-named technique there is (apart from SEXAFS - surface extended X-ray absorption fine structure). So it's not uncommon to have a conversation along the lines of:
"What are you up to next week?" "Oh, lots and lots of SAXS."
Or, "If we'd done the SAXS earlier, we would know if things were working or not."
In fact, at one point last year I gave two talks at work about some computer programs I have been developing to analyse SAXS data. I called the first, 'Getting the most out of SAXS' and the second 'Getting even more out of SAXS.' Strangely enough, hardly anybody came along. Then there's the all-popular title, 'Everything you wanted to know about SAXS but were too afraid to ask.'

Man, I need to get some sleep!