Meet the scientists!

It is a bit of a cheesy fact but it is true: we are all star children. The carbon, oxygen and other chemical elements from which are bodies are made were cooked up inside the heart of stars over billions of years. But where did stars get their fuel from? The answer lies in the first few seconds of the Universe, just after it’s Big Bang birth. The secret is locked away in natures smallest building blocks – the particles.I study the way particles interact with each other and themselves. I am looking for very very very rare types of interaction, about 1 in 10,000,000,000, which gave birth to the star fuel. This involves using powerful particle accelerators, atom smashers, and massive detectors.This is a picture of one of the massive particle detectors used in the experiment I am working on. It contains over 33 Olympic sized swimming pools worth of water and is a kilometre underneath a mountain in western Japan. If you looks closely you can see two men in a rubber boat checking the electronics, just to give you and idea of how big the thing is.The experiment I work on, with over 500 other scientists and engineers, is based in Japan. The particles we use are called neutrinos, if you haven’t heard of them I am not surprised. Trillions of neutrinos pass through your body every second, on their journey through the cosmos, but you would never notice them. The are anti-social particles, very rarely interacting. This means that we can fire a beam of neutrinos a whole 295km from one side of Japan to the other right through the Earth. From the few interactions we get in our detectors we try to piece together an understanding of how the Universe was born.If you have heard of neutrinos it may have been from the claims suggested by CERN that they might be able to travel faster than the speed of light. The experiment I work on, in Japan, is very similar to the OPERA experiment which suggested that this might happen and we will also be looking into this too. If neutrinos do travel faster than light then we would have to re-write all of our textbooks as it changes our surrent understanding of the Universe on all scales.Above is a particle physicists view of the history of the Universe – take a look at the time scale along the bottom; particle physicists like me are interested in the very first few seconds after the Big Bang.Here is a diagram of the building blocks of nature, the forces they feel and the particles that transmit the force.

More on my experiment

The experiment I work on is split over a massive diastance; from the very East Pacific Ocean coast of Japan, just north of Tokyo, to the Mountainous Japanese Alps 295km to the West.

It all starts with a particle beam, infact we use one type of particle beam to produce a second beam of particles that we need for the experiment. Protons, just the same as in the Large Hadron Collider (LHC), are acellerated in a machine called a synchrotron. Instead of smashing these protons into each other we crash them into graphite, the same stuff as in the centre of a pencil. This gives birth to new particles which in their death produce a beam of neutrinos – the particles we want. See if you can spot the stage at which the neutrinos are created in the animation below.

Just after we create these neutrinos they pass through a “near detector”, called ND280, which takes a snaphot of just a few of the trillions of neutrinos created. This snapshot lets us understand how many of each type of neutrino was in the beam and what energy they each had.

The neutrinos then travel 295km, straight through the Earth, to another “far detector” which is called Super-Kamiokande.

Super-K, for short, also takes a snapshot of the beam of neutrinos and tels us how many of the different types of neutrino we see and at what energy. This Super-K snapshot is compared with the ND280 snapshot and from this we can determine exciting physics as I described in “Me and my work”.

This is what I do with most of my time although it is difficult to say what a typical day is exactly.I am responsible for processing a lots and lots of data from our particle detectors on a huge worldwide network of computers called the GRID. I also develop computer programs to recognise patterns within the detectors, so that we know what particles we are taking photographs of.Some days I may be in a sterile clean room assembling and testing electronics; such as the ultra-sensitive light sensors we use to detect a single particle of light (photon) at a time. Other days I could be looking after one of the massive particle detectors, making sure that everything is running smoothly.I also have lots of meetings and conferences to attend and these can be all over the world or just a video conference at any time of the day or night. Travelling is a big part of my job as well, mainly to to Japan but I also find time (and reasons) to get to go to other interesting places in the world. Ocassionally I get to escape my desk and build LEGO Universes, teaching people of all ages about the birth of the Universe and the particles and forces that make it.

I have been writing a blog for a while now, The Neutrino Blog, and I would love to make the best of these posts into video podcasts for all to download and learn about neutrino and particle physics. I am a visual learner and much prefer producing video and animations than written stuff.