Accelerators

The day the results of the recent referendum was announced was also the day of the accelerator, that is to say a discourse about accelerators at the Royal Institution from an accelerator physicist at the University of Oxford.

Started off in the usual way with a quick perusal of the expensive art work for sale in Albemarle Street followed by a spot of white in the Goat. Lots of people outside, most of whom were not smoking, less inside - perhaps because of the noise coming from the televisions. Or perhaps the loudspeakers.

Onto the lecture where, although the lecturer was an old hand at selling science to the general public, somehow I felt right from the off that she had not pitched this one quite right, at least not quite right for me. Maybe she was thrown by the (usual) mix of school children, colleagues, older scientists, drop-ins and university of the third age types (in which category I put myself).

She had some clever toys with which to make some of her points, with the one I liked best being a tube maybe two feet long and three or four inches in diameter with a yellow beam of electrons down the middle, a beam which she was able to move about with an ordinary magnet. Nothing particularly fancy, being only a more visible version of what an old fashioned television used to do, but I had not seen such a thing before.

Her main point seemed to be that there are lots of beams of particles which need accelerating about, with ten of thousands of them in various bits of medical equipment alone: not all of them are on the scale of the collider underneath the Swiss-French border which we had first heard about getting on for two years ago. See references 1 and 2. Very useful things, despite the skepticism as to real world applications which had greeted their first arrival in the world, more than a century ago now. And all described by much the same sort of equations. So a puff for pure science - for science which in her case depended on the EC for around 10% of its funding.

There seemed to be some kind of a trade off between beams travelling very fast - which I think is power - and the number of particles in the beam - which I think is intensity. But she failed on Friday and google fails today to clarify the point.

Another angle which could do with clarification is the idea that you don't actually want the electrons. What you actually want is the second wave of particles that you get when you fire the electrons at something, perhaps a sheet or slab of some metal or other, and these are the particles which do your business.

Not to mention the whole tricky business of focussing your beam, something it seems that you could only do in one plane at a time. Failure might mean burning an expensive hole in one's beam tube.

All in all slightly depressing that I have devoted several hours to these beams and their collisions now, but my knowledge remains terribly sketchy, with most of what was taken in now having faded away again.

Half Way House at Earlsfield all present and correct though, if surprisingly quiet this Friday evening.

Reference 1: http://psmv2.blogspot.co.uk/2014/09/hadrons.html.

Reference 2: http://psmv2.blogspot.co.uk/2015/11/luvvy-spotting.html.