Beginning to scatter

1.14pm. After the end of the electrical oscillations lab, we went outside for coffee. Dunc spent a fair bit of time fiddling with his radio, to try and get some cricket scores, none the wiser. I chatted to Alex for a bit, and we've swapped email addresses. It will be great to keep in touch with him, he seems very sound.

Dunc on his radio.

David Keen found us outside, and he chatted to me for a few minutes. He said, unashamedly in front of my (new, admittedly) friends that he thought I'd done a marvellous job of writing the Frequently Asked Questions for the SXR103 forum (the University of Sussex course that I did in 2009). I was surprised and humbled by his praise, which was completely unexpected. It is a pleasure to give something so small back to other students of the OU, but this pales into insignificance when I attempt to contemplate the contribution that David has made to the OU.

I gather from reading posts on the SXR207 course forum that he has been working for the OU for 40 years. I know he also works hard on the S207 preparation and S207 revision weekends, which he most certainly doesn't have to do, and I suspect that far from covering his costs, he probably loses out - except that he seems to drink in the quiet gratitude of his students without pride. Where he gets his energy from I have no idea; I don't have that amount of energy now, let alone what I might be like in my sixties. The fact that he is part of the OU, and I am part of the OU, makes me immensely proud by association.

But I digress.

After the coffee break was over, we walked back inside. After some difficulty finding the right room (we went past Dr Fong's room - what a cool name for a Marvel comics villain!) we found ourselves in the Compton Scattering lab.

Tom and Nick. Lousy photo, it was a frame grab from a video.

Nick Braithwaite, one of the tutors did a lengthy but necessary safety briefing. Nick sounds like a cricket commentator, a cross between Michael Parkinson and Peter Allis, so I've been careful not to repeat my anecdote about picking up a moaning Yorkshireman on my radio, in case he turns out to be from Yorkshire himself!

Once we got going, we used a discriminator to measure radiation counts at an angle of zero degrees at specific energy levels from a fairly chunky Caesium source, guarded by fairly substantial lead blocks, moved in and out of the way by pinball style levers. Later we'll be looking at other sources taken at different angles (which is why the angle comment was relevant).

Tom Wilks, the other tutor for this lab, recognised me, and realised that I'd done the course before. He tactfully didn't enquire why I was doing the course again, and I was glad of that. He might ask later, and if he does, I'll tell him. But he's highly entertaining. I have intentionally told few people that I've done the course before. Duncan knows, and one or two others in the group do, but there is no sense in making an announcement, as it were. If people know that I've done the course before then there may be an expectation that I know it all, and clearly I don't, because this is my second attempt.

After getting count readings from discriminator settings 0.0 to 10.0 in 0.5 degree increments, we plotted a rough graph of the very high peak (and I mean high; the readings rocketed from about 250 counts to well over 6,000). Then, we took finer measurements in 0.1 increments around the peak to try and get a more accurate location for it.

Textbooks already tell us that this peak is at the 662 keV mark, so measuring where this peak appears on our equipment is the first step in producing what is known as a calibration graph.

That took us until lunchtime. Dunc and I walked back up the hill, and we talked about Malta en route. He's off there shortly, with his missus I am presuming, and his daughter. His daughter suffers from Asperger's Syndrome, which must add an additional dimension to parenthood. It's something I may have to consider the possibility of, in time.

At lunch, I sat with Tom Wilks, Dunc and another guy whose name I don't yet know. Tom lives in Barnstaple, fairly close to my parents. He used to teach full-time, but because he has a severely disabled son, George, Tom now works pretty much full-time for the OU from home. My respect for him increased further when he told me that he's also an OU student himself, doing his masters in education. A weighty and worthy topic, I salute him.