16 June 2008

T2K is Coming Along....

It has been a few years since our group started working on T2K, and as with any experiment, initially there was lots of talking and designing and re-designing, but without very much to show for it all, at least in a form that can be appreciated outside of physics meetings.

But with less than a year to go till we start taking data (which is a scary thought), we now have some photos and videos to prove that T2K construction is right on track!
The picture on the right is something I generated a while ago from the representation of the T2K near detector in the computer simulations that we have been using to design and study it.
The movie shows the magnet coil a week ago, being put inside the red magnet, which has already been placed 20 metres underground in the brand-new detector cavern. All 900 tonnes of the magnet were shipped all the way from CERN just a few months ago. Note the uncanny similarity between the picture and the movie.... The movie is sped up by the way -- the workmen don't actually whizz about like that.
It is a proper experimental hall now, but on the right is how the "cavern" looked when we visited J-PARC 9 months ago in September 2007--barely a scratch on the surface!
The near detector is being built in the ground about 280m from the origin of the neutrino beam that is also undergoing construction, so that we will be able to measure the beam and understand the interaction properties of neutrinos well enough to be able to measure it again at Super-Kamiokande, 295 km away, which is the point of T2K.
The cage-like object rendered in brown in the picture at the top is what we call the "Basket". It sits in the middle of the magnet, and holds up the P0D, FGD, and TPC detectors inside. This was one of the UK responsibilities, and in this picture you can see our colleagues from up North inspecting it when it was finished. Since it goes inside a big magnet, the Basket, and everything else too, needs to be made of non-magnetic materials, and that was one of the things they checked.
I hope it goes without saying that the Basket is not the only thing we are building for T2K in the UK! The Electromagnetic Calorimeter, or ECAL, which the UK is responsible for, is also coming along nicely, as is the neutrino beamline itself. I think I'll save those for another post though....