Despite its size, ATLAS is not a completely stationary detector. It has a stationary infrastructure but it does have some parts that can move around, allowing for access to the internal elements of the detector. (By contrast CMS is very mobile–it is like a gigantic Yule log where each section can be separated from each other.) On each side of ATLAS, there are three big moveable parts as seen in this picture. The muon wheels shown by the turquoise arrow can be moved back. This allows for the end-cap magnets indicated by the red arrow to be pulled out. Once the end-cap is moved, we can gain access to the extended barrel calorimeters (such as TileCal). The extended barrels shown by the blue arrow can also move forward, allowing for access to the calorimeter barrel as well as the inner detector. But space is limited so it is not possible to access all places at once. And so in typical ATLAS fashion, there are committees in place to organize who gets access when.
But the end of April is ‘the closing’. Or perhaps I should say THE CLOSING. Or maybe even, THE CLOSING.
Where all the moveable parts are put into their final location. And the installation of the beam pipe and the beam pipe shielding begins.
The bad news is that we will lose access to the detector. The good news is that it means the beam is coming.
The closing is one of those things that can simultaneously fill you with ecstatic excitement and absolute panic. And it really is a simultaneous feeling. On one hand it is like sitting in a Ferrari waiting for the keys. Feeling the pressure of the seat against your back, the feel of the wheel under your hands, anticipating the roar of the engine when you hit the gas and thinking, ‘Alright. Show me what 0 to 60 really means.’ And yet at absolutely the same moment, it is like the night before your last final exam. Staring intently at a pile of books, willing the information to leap out of the pages and into your brain, lamenting, ‘why didn’t I get to this sooner’, but knowing that it was impossible in any case because you had other exams which took precedent.
But heedless of anyone’s feelings on the subject, the closing approaches. And I will bet that as it continues to approach the two most common phrases in the halls will be either ‘We are closing soon, the beam will be here!’ or ‘We are closing soon, and it is the end of January already. How did it get to be the end of January already?!’.
The end of April, it is so far and yet so close.