It is a moment both longed for and dreaded: The closing of the calorimeters. To us on TileCal the calorimeters closing says two things. On one hand it says, ‘What a relief! Finally no more repair work’. And on the other it says, ‘What! We are closed? Now there is no more repair work.’ The thing about hardware people is that we get very, very uncomfortable when we can’t actually touch the hardware. So the closing is a very painful but necessary transition. While we are all very glad that the calorimeters have finally closed, we are all still a bit nervous about it. But this will fade.
The Tile calorimeter is divided into three parts, two of which are movable. There is one ‘barrel’ section of about six meters in length and two ‘extended barrels’ (on each side of the barrel) of about three meters long. In the ‘open’ position, the two extended barrels can be moved about three meters apart from the barrel section. The movement of the extended barrels back into their usual position (next to the barrel) is an engineering feat on its own. Not only is it big and heavy, it also has thousand of cables connected to it. As it took years to connect all the cables going to the extended barrel, it is not possible to disconnect them before moving. Instead the cables were made longer (for some slack) and then put in ‘flexible trays’, so that when the extended barrels move the flexible trays can move with it. Hence no recabling!
This picture was taken during the movement of one of the extended barrels. The perspective is from the bottom of the extended barrel looking up. The blue boxes on the outside are where Tile’s power supplies are located. But despite our unhappiness with no longer being able to touch the hardware, now that the extended barrels are in their final position, we can certainly breath easier. The movement went very smoothly, nothing crashed or crushed or squished or squeezed. And now we are one step closer to being ready for beam!
