QUESTER 6 visit the Synchrotron

The afternoon visit to the Diamond Light Source (DLS) at Harwell started with a lecture by our guide, who explained the functions of DLS and why it had been constructed. Needless to say, the whole thing is very complex, but I think that most of us grasped how it worked at the end of the talk. Then it was time to visit to the machine itself. And what an impressive piece of kit this is (Think of a huge concrete doughnut in a building covering several acres and you have the picture). I have not even attempted to write up this report using my own words but have shamelessly copied information from the Diamond Website. Here are a few extracts:

Diamond Light Source is the UK’s national synchrotron facility. By accelerating electrons to near light-speed, Diamond generates brilliant beams of light from infrared to X-rays, which are used for academic, and industrial research Our eyes can distinguish between millions of different colours of visible light, each colour having a different wavelength. However, there is a huge range of the electromagnetic spectrum that we can’t see directly including radio waves, microwaves, infrared light, ultraviolet light, x-rays and gamma rays. A synchrotron is a huge scientific machine designed to produce very intense beams of x-rays, infrared and ultraviolet light, called synchrotron light.

For centuries scientists used microscopes to study things too small to see with the naked eye. However, microscopes are limited by the wavelength of the light that they use, so to study smaller objects like molecules and atoms, we need to use light with shorter wavelengths like X-rays. Diamond can generate synchrotron light from infrared through the visible range and ultraviolet up to X-rays. Synchrotron light can be as much as 100 billion times brighter than the sun. This allows scientists to study samples in incredible detail, to a level that is only possible at a synchrotron.

Particles called electrons are generated in an electron gun, very like the cathode ray tubes found in old TV sets. These are then accelerated up to very high speeds through a series of three particle accelerators. These are called the linear accelerator, or linac, the booster synchrotron and the large storage ring.

The storage ring is not a true circle, but a polygon, made of straight sections angled together with bending magnets. These bending magnets are used to steer the electrons around the ring. As the electron passes through each magnet it loses energy in the form of light. This light can then be channeled out of the storage ring wall and into the experimental stations, called beamlines. Diamond is free to use and over 2000 researchers from academia and industry use Diamond’s beamlines to conduct experiments in a wide range of disciplines including structural biology, health and medicine, solid-state physics, materials & magnetism, nanoscience, electronics, earth & environmental sciences, chemistry, cultural heritage, energy and engineering. This work now generates several hundred research papers every year and the rate of publication continues to increase as the facility expands.

At our traditional pub supper which followed our visit, we all agreed that this was the sort of visit that the U3A is all about: it was fascinating, it stretched our minds, and we learnt a lot of things that we didn’t know beforehand. I now suggest that you go to www.diamond.ac.uk for a fuller and excellent description. Many thanks to Ann Rich for organising an excellent outing.

Margaret Henstock