Archive for the ‘Shutdown Weekly’ Category

Week 39: Doing archaeological work

Added July 23rd, 2010 in Shutdown Weekly

At this time the vast majority of the existing carbon tiles have been removed. The attention has now turned to performing the photographic survey of the inside of the torus as the first-wall is exposed. The need to do this with the accuracy nowadays available is to confirm that all the new components to be installed will fit.

Week 38: Reliability comes with an effort

Added July 16th, 2010 in Shutdown Weekly

The high reliability of JET is achieved through insistence upon very high Quality Assurance requirements, similar to those needed for aircraft components.

The photograph shows some new water pipes that are being installed to bring cooling water to the new actively cooled duct liners.

Week 37: Pure nothingness

Added July 9th, 2010 in Shutdown Weekly

Helium gas is used for several reasons. The helium atoms are small and they easily pass through tiny holes. There is also very little helium present in normal air, and it is non-flammable and therefore safe to use. It also has the useful property that it is very light. It is familiar to most people [...]

Week 36: A huge amount of energy

Added July 2nd, 2010 in Shutdown Weekly

The Neutral Beam Enhancement project has been mentioned previously as part of the upgrade of the neutral beam injection system. This week’s picture shows the ‘blocking diodes’ which are part of the new power supplies for NBE. They have been installed in a first floor building above the water chilling plant adjacent to the J1H building.

Week 35: On the move

Added June 25th, 2010 in Shutdown Weekly

There is a regular requirement to move components from the JET torus to the Beryllium Handling Facility for refurbishment or storage. All the in-vessel components are wrapped and stored inside a modified ‘ISO Container’ like the one shown in the photograph. [...]

Week 34: Freeze drying!

Added June 18th, 2010 in Shutdown Weekly

During the work on the Neutral Beam Enhancement project, many components have been removed from the neutral injection boxes (NIBs), allowing internal components to be examined in more detail than has been possible for several years. [...]

Week 33: Upgrading the neutron spectrometer

Added June 11th, 2010 in Shutdown Weekly

JET’s 14 MeV neutron spectrometer (known as “Magnetic Proton Recoil Spectrometer”) was originally designed to analyse the energy of the neutrons produced during deuterium-tritium experiments. It has been upgraded to produce useful data for normal operation with deuterium alone.[...]

Week 32: Maintaining the Lower-Hybrid launcher

Added June 4th, 2010 in Shutdown Weekly

The Lower-Hybrid Current Drive (LHCD) system is an important part of JET that is used in experiments to drive current in specific regions of the plasma. Microwave power at 3.7 gigahertz is generated by a set of klystrons, and up to about 5 megawatts is ‘launched’ into the plasma through an assembly of waveguides which can be moved close to the edge of the plasma. [...]

Week 31: An early riser again

Added May 28th, 2010 in Shutdown Weekly

In week 20 we described the two flywheel generators, their specifications, their reliability and their role in supplying power to JET. The team of engineers from our sub-contractor Cegelec, who maintain these large complex machines, have had an opportunity to carry out some major maintenance operations this year.

Week 30: In-vessel survey in 3D

Added May 20th, 2010 in Shutdown Weekly

Components inside the JET torus need to be installed with great accuracy. Diagnostic Engineer Guy Sandford in collaboration with University College London, has developed a new stereo-photography system. This system is capable of doing a three-dimensional survey of the whole bare wall before the new tiles are installed.