Posted on: 18th March 2011

As the upgrade work on the neutral beam duct cooling draws to a close, it has become possible to start reinstalling a lot of other components at Octants 4 and 8. Much of the equipment has been in storage since early last year.

At Octant 8, a set of access stairs and a platform have been lifted back into place, followed by a new support structure for a ‘neutron collimator’. This collimator is a 250 kilogram multi-layer sandwich of lead and polythene sheets with a central hole. It acts rather like a (non-magnifying) telescope in that it will allow a diagnostic system to ‘look’ at the plasma with a well defined field of view.

Meanwhile, at Octant 4 the scaffolding has been modified and another diagnostic system has been installed. This system has been upgraded since it was removed. It uses a plate coated with a scintillating material to detect alpha particles that escape from the edge of the plasma. Following that, some work has been done on one of the viewing systems that allows observing the plasma during a JET pulse.

The end of the shutdown is clearly approaching us and the number of activities in the torus hall is ramping up.